Jeff Perrin

Mar 142008


This is a test you will none of our competition do! We have always wanted to prove that a PERRIN turbo inlet hose was more than just a good replacement for a failed OEM part. We know it makes more power and allows the turbo to spool faster, and there are a few results online, but all these tests were done days or weeks apart. We always wanted to prove how it works and do an install within a couple hours, so we just decided to do it one day!

We started this test on a 2008 STI with a previously installed PERRIN Cold Air Intake, PERRIN turbo back exhaust system with (2) high flow cats and a custom Accessport tune.  We made roughly 5 runs until the power settled out, and then we started the PERRIN inlet hose install. The installation took about 45 minutes and in about 50 minutes total we were able to do a few more dyno runs to see how the PERRIN inlet hose affects the car.


Dyno Proving

The below green line shows the best run with the stock inlet hose, and the purple line shows the best run with the PERRIN turbo inlet hose. The result that really surprised us was the change in boost. This proved 2 things:The stock inlet hose is a restriction holding back the turbo from spooling up, and it shows is how much freer flowing the inlet hose is above 5000RPM.  Where the ECU built more boost at low RPM it created more TQ, and where it added more boost above 6000RPM it also added more HP. Funny, more boost equals more HP???


The HP graphs showed where more the increase in boost equalled more torque and more power! Since there was more boost from 5000- redline, HP increased about 10WHP all through this range. The more impressive gain is with the torque. Since the turbo spools up quicker, there is an increase of 100ft-lbs at 2700 RPM! After driving the car, the low end is very noticeable, as is the top end power! Another thing to note is these results are still with the stock TMIC and stock headers!  Oh, and don’t forget 2 cats in the PERRIN Downpipe!



Proof of the Test Being Back to Back

We wanted to make sure that customers knew this was done on the same day so we setup our camera to take pictures during the install with time stamps to help document this. Since I was not being put on the spot, I decided to see how fast we could install one of these. A few bets were made as to how fast I was going to be able to do it. Now it had been quite a while since I had install one, but now I had a camera taking pictures over my shoulder, the challenge was on! After the install was all done, I was surprised that I did it in 37 minutes!  I think had I been a little more prepared (should have grabbed a part off the shelf) and with a little practice 30 minutes is totally doable.  Since I had John h taking pics of the install over my shoulder, we turned the install into a quick video.I was like how about an hour I did the install in about 45 minutes time, which was pretty fast and something we thought people might like to see. So we made a little video to show how easy this was. I think we ended up with two really cool things:The fastest turbo inlet hose install ever, and the only  back to back inlet hose dyno runs ever done!


The PERRIN inlet hose used here is the newest version of one of our best selling parts ever.Lots of good info on the Evolution of our PERRIN inlet hose can be found here. The biggest change to our turbo inlet hose is the new skeleton.  Our past hoses were all constructed the same, where the multiple layers of silicone and polyester to create a stiff hose that would hold up to intake vacuum. There was a huge “Internet” issue where a few people had a hose collapse on them during high HP runs. The issue was due to the silicone not being cured long enough and the introduction of engine oil to the hose which softened it. To this day, roughly ten out of thousands of parts were returned to us with the collapsing issue. While this was a very small issue to us, it was publicly exploited on the Internet and made out to be a much bigger problem that it really was.

To remedy this problem and ensure that ZERO hoses got returned for collapsing, we added a a skeleton to support the hose. We added a stainless steel wires through the middle of all the layers of silicone, which adds more than enough support to eliminate the hose collapsing. Over time we have done other minor tweaks to make the hose easier to install or better performing. All these changes will make an already great part even better and with ZERO change in price.IMG_2145


Mar 142008

This test was done on our 08 STI shop car.  Before we get to far into the fun stuff, the STI is in our Stage 2 form. This means it has our twin cat downpipe, 3€ quad tip exhaust, and our Stage 2 AccessPORT tuning.  With that said we are going to show 2 tests in this article one, the PERRIN 08 intake and the PERRIN  Version 2 inlet hose.

First lets explain the dyno and testing methods we are using.  In Oregon, we have 92 octane, using that fact, in stock form our put down numbers a little higher than 91 guys but a little lower than east cost guys. But still our 235WHP was pretty similar to what many people are seeing.  Our dyno we are using is a Dynapack dyno.  This isn€™t a dyno that reads high, or really low.  In fact it seems to be pretty close to the mustang dyno in how it reads for most cars.  All of our runs are done in 5th gear, and run for 14 seconds.  Both of these factors play into the actual HP and TQ numbers we see.  These factors are important to mention and important to understand as they can be manipulated to change the results.  We could have made the dyno read a bit higher, by changing to 4th gear, or making the run shorter, but for tuning purposes, and future part comparos, this is what we decided on.


The new intake system is different than other silicone versions we used to make. We are moving more toward all aluminum intake systems in general on old and the new car. So this is the first all aluminum intake you will see from us.  Using our newest MAF housing design, which incorporates a partial velocity stack into the front, we have a simple tube mating it to the OEM inlet hose.  What is different about this intake as well as the future ones, is that its ONLY a cold air design.  The filter is located down in the fender behind the fog lights and where a nice fresh bath of cold air is constantly passing by.


First up we did some runs and a little more tuning to our Stage 2 mapping.  With that said we had our base line before we installed the intake system.  Initial testing on our intake system showed the MAF curve was pretty close to the same as stock.  Our first couple runs show that it leans out the AFR€™s almost 1 full point.  For a tuned car this is not good, for a bone stock car it is good.  With that said this intake will be one that requires a custom ECU tune.  Our intakes in the past didn€™t have this issue, but this could be do to the change in the new MAF sensor, or the change to the intake housing.  Either way we will be selling this as an ok part for a stock ECU tune, and a custom tune required for a car with an AP.

Our initial results with the car running leaner were very good. But it was on the verge of being a little dangerous for the off the shelf mapping.  Also since the intake made the car run leaner, this doesn€™t prove that that intake being freer flowing makes more horsepower.  This is important to note as we do not want to trick everyone into thinking our intake make more power than others.  So in order to keep things all square and equal, we retuned the ECU to the same AFR as our stage 2 tune. This way the gains shown are gains from the intake flowing more air, not from MAF trickery.  What is strange is that with out retuning the ECU we were seeing about the same power!  Adding back in the fuel only caused a loss of about 3-5HP.


Even with all that said, 20WHP on stage 2 PERRIN map is huge!  One other thing to note is the boost.  Boost was the same before and after the install.  Below, the green line represented the boost we were seeing.  So what created that purple line??



 Posted by on March 14, 2008 Dyno Test & Tune Tagged with: , , , , , ,
Mar 122008

The PERRIN turbo inlet hose has been one of our best selling, long standing products for many years. Since the beginning, we have made our part different than the rest in that we didn’t just make a copy of the OEM part.  We had something different in mind to make the installation of this go much easier, and also out perform other turbo inlet hoses offered by our competition.


When we got the WRX and started making parts for it, we looked to Japan for some of our inspiration, as they had the car for much longer. One of the more common parts we saw people replacing was their OEM inlet hoses. Before we had decided to make one, we had been installing these on customer cars for a couple years and come to hate the installation. This was due to the removal of the intake manifold, which meant about a 3 hour install job. This seemed ridiculous as the customer would buy a $300 part, then pay $200-300 to have it installed. All this for about 10HP? This is what sparked us to make the PERRIN inlet hose. We wanted to make the installation quicker and the part less expensive so customers would pay more like $300 installed.


We looked at many different ways to build it.  The criteria was that it had to be easy to install and inexpensive enough so the value equaled the HP gained.  Sounds easy!  I spent a lot of time trying to make some from carbon fiber. This entailed a pattern of the inlet hose, and a mold of the pattern.  A wax casting was made from the mold and a carbon “sock” was pulled over it. When cured, we just heated it up and out came the wax.  This didn’t work so well and was super messy.

Before the mold was thrown away, we tried one last thing.  A carbon fiber “sock” was pulled over a specially made bladder, and inserted into the mold.  With resin soaked into the carbon, and the bladder pressured up the mold, out comes a carbon inlet hose!  Sounds complicated, but this is how a lot of these kinds of things are made.  However, for a smaller company like us, it was messy and time consuming.


So the next best thing was silicone. Silicone is flexible and this would be great for installation.  After a little engineering and after NOT looking at the stock part, we created our first prototype tool.  Looking at this from an installers point of view, we came up with the idea to move the spigots around to make the part installable while keeping the manifold bolted down.  This simple idea not only eliminated the need of the intake manifold coming off, but it eliminated cost in installation fees.


This polished Stainless Steel tool created the hose you see below. Silicone is wrapped around the tool, then mylar is wrapped over this to keep the silicone tight to the tool. It is then baked in an oven to cure and then the hose is removed from the tool. The process for doing this is very labor intensive, but it creates a hose that is very durable, easy to install, and very heat resistant. The first version of this hose was made in 4-ply’s (silicone and polyester). Later on we changed it to 5 ply’s and a longer cure time to stiffen up the hose a bit.


Over the years, competitors have come into the market with similar parts, and taken some of the market share.  This has driven us to look at new methods of building the hose, as well as making it even better. We could make it from an aluminum tube, but someone already does this. We looked at a cast aluminum part, but it would more expensive than the silicone. Every method we looked back to all had the same problem, installation time and cost.  Instead of reinventing the part, we decided to build upon our silicone design and make it even better.


So how can we make the part better?  A very small but damaging issue we had with some of our parts, was the reports of them collapsing.  To this day roughly ten out of thousands of parts were returned to us with this issue. The issue was due to the silicone not being cured long enough. While this was a very small issue to us, it was publicly exploited on the internet and made out to be a much bigger problem that it really was.


Again, this small issue could be completely remedied if we made a simple and effective change.  We could add a wire that would run through the middle of the hose and would provide enough support that collapsing issues would be gone completely and still be able to install it! So there we have it!  Along with the added wire, we moved the spigots around, increased the spigot sizes, added some additional connectors,  and added slight revisions to the instructions. We feel that these changes will make an already great part even better and with ZERO change in price.



Again, we tried to one up our competition and prove that our part made HP versus just claiming it made HP. We had done tests in the past that were days or weeks apart and they always showed more boost and power but, they were not done close enough together to use this as proof. So we decided to do an install on the dyno on the same day to ensure that the testing was as legit as possible.

When testing parts, sometimes we look how much power is gained by just bolting it on, and sometimes we look at how much HP is gained by bolting it on with an ECU retune. If we can show that a part makes power with just bolting it on, this normally means that even more can be had with a custom tune. In our testing we found that there are gains had without custom tuning, which is awesome as even more HP will be gained with further tuning of the ECU.


There are 2 very important parts of the RPM band to look at.  The green line represents the boost on our car (Stage 2 STI) with the stock turbo inlet, and the purple line shows the same car with a PERRIN inlet hose installed. These runs were done roughly 40minutes apart, removing any major variables to HP and TQ. As you can clearly see, the OEM inlet hose is a restriction as the turbo builds boost faster and holds more at higher RPM.


The power graphs show the turbo spooling up quicker and netting more low end torque and power.  At the same time, the slight increase in boost at the upper RPM provides more HP from 5500 RPM. An ECU retuned specifically for the inlet hose could net a few more HP as the turbo runs more efficiently.  But for the above test, we are running our Stage 2 mapping that was designed for the Intake system. This is showing the real world HP that other customer should expect to see.



We have the advantage over other brands. Our inlet hose is the only one on the market today that does NOT require the removal of the intake manifold! That is HUGE. Think about it, no fuel to drain, no water lines to remove, no gaskets to purchase, less nuts and bolts to deal with. A huge advantage if you do it yourself or pay a technician. Instead of paying for 4-6 hours labor and parts, you should only have to pay for 1-1.5 hours and no extra parts.

To add to that, we are the only ones to prove our part makes power!  When testing parts, we look at 2 different things, bolt on power, and ECU retune power.  Because we can tune the ECU and make power, it is important to look at both methods to show real world gains and gains after a tune.  For this part, we see great gains with no tuning, which means with an ECU retune there is even more to get!

Below is a comparison of the PERRIN inlet hose compare to some of the aftermarket ones offered. There is not one single competitive brand mentioned below, its more of a conglomeration of all aftermarket parts.

  • PERRIN Inlet hose is made of high quality polyester reinforced 5 ply Silicone rated to -75F to 400F
  • OEM is made of plastic and rubber which cracks over time


  • PERRIN Inlet hose has a thick steel wire reinforcing hose from collapsing under extreme conditions
  • Their Inlet hose has no steel wire keep hose from collapsing.


  • PERRIN Inlet hose doesn’t require removal of intake manifold making install time to be about an hour.
  • Theirs requires intake manifold to be removed making install time 3-4 hours


  • PERRIN Innovative design with larger inside diameter and relocated spigots
  • Theirs, a copy of the OEM hose with little to no performance benefit.


  • PERRIN proven HP done on dyno with back-to-back testing done in under an hour.
  • Theirs, no dyno numbers, just claims of more airflow


  • PERRIN Inlet hose Includes hardware and hoses with detailed instructions on how to install
  • Theirs has nothing but a hose and expects you to “know” how to install it.


  • PERRIN inlet hose includes hardware to make it compatible with other intakes and Front mount intercoolers
  • Theirs not always compatible with FMIC’s and aftermarket intake systems.


 Posted by on March 12, 2008 Dyno Test & Tune, Part Design & Tech Tagged with: , , , ,
Mar 082008

When we got our 08 STI, we went over the whole car and pointed out all the differences, and made comments about the changes.  Now that our EVO is in our hands, it gets a turn under the microscope.  PERRIN as a company was a little unsure of what to do about the EVO old and new.  There isn€™t many of them compared to STI€™s and the customer base is very different that the Subaru guys.  There were already some established companies making parts for them out there, and while we were one of the first people to our EVO 8 a long time ago, our brand name didn€™t really stick with the EVO guys.  The EVO was on the chopping block ready to be diced and cooked, then a long time customer of ours stopped by with his new X.  From that day on, things changed!  The car looked sweet, but not too €œricer boy€, gone was the boring interior, and other things that plagued the older EVO.  Not to mention our customer let me take it for drive, which was pretty nice.  My initial impressions were, Its not slow, Steering is sweet, seats are sweet€¦..maybe we need to rethink the EVO??  Also in the back of our mind was the fact the Ralliart EVO is coming out soon, which will bring the EVO to many customers not able to spend $35K.


First off the obvious, the body.  I love the looks of the new EVO. In the pics and articles I saw, I really liked the nose, but the rear looked really big.  Much bigger than the older car, or WRX/STI. But in person, both cars sitting next to each other my mind change a bit.  The front looks way more aggressive than the older EVO, the flares the side skirts, and everything from the front to the middle of the car is really making me want to buy this car.  But whats with this useless Toe hook port, am I missing something??

yup, nothing behind here???

Now onto the rear.  It is way bigger/taller than the previous EVO, but its not that bad. The black lower part of the bumper really breaks it up.  The wing on the car we saw was the taller wing like the good old Carbon fiber wing of the past. Many guys explain their dislike for the newer €œCheaper€ Wing, but I can see beyond the missing carbon.  Mitsu was smart in ditching carbon for plastic in that it can save costs in many ways. Not only cost to build, but to replace when someone gets in a wreck. I like the 2 tone nature of it along with the additional diffuser at the top.  The shape of the wing is that of a true race car, with the center foil being at an agle to catch the wing coming off the roof.  Like the APR wing used on so many import race cars. (Not import €œracer€ cars but real race cars).


Very cool detail on the X’s wing

One thing I liked about the body that is very similar to the STI, is the side vents.  These vents really and some flavor to the rather plain side panel. Its not really that plain but compared to the STI with the over exaggerated flairs it needed something.  Again like the STI these vents are functional.  They let built up pressured in the engine bay have another place to go.


Mitsubishi very elegantly did away with the monster vent in the hood, and added smaller vents.  The front 2 vents are just like the older car where they help get rid of the heat and air coming through the radiator.


The new vent Mitsubishi added was the center scoop toward the rear of the hood.  The older vent in the from the EVO 8 and 9 was not only for the radiator, but to help get rid of some of the heat coming off the turbo.  On the X, Mitsu installed a scoop to blow cool fresh air over the turbo that was now mounted at the rear of the motor, not the front. More on this scoop and its functionality, later.


The body, under the car, has some other cool things I really like.   Starting at the front of the car the first thing is something I have seen on Porsches.  The front brake vent/scoop mounted on the control arm.  Mitsu was very smart in how this was adapted to the body and chassis.  The lower €œskid plate€ has channels molded into it to direct air flow right to these scoops. The scoops, simply blow air over the rotors.  Simple, effective, and clean!


Working our way back to the rear of the car, I noticed another really cool thing.  The EVO has a built in tranny cooler!  Again it uses the air already traveling under the car and scoops it up and directs it over the tranny and center diff housing.  Again, simple, cool and effective!


In the middle of the car is another small thing to help with wind turbulence under the car.  These little flappers are probably there for 2 reasons; one is for keeping road grime off the suspension components and two, for deflecting wing over the suspension components.  This helps reduce wind drag and cut down on road noise.  This is a common thing found on many Euro cars, first time I have seen it on a car made in Japan.


The rear of the EVO has a few very subtle vents. Its these really small details that make me like the EVO more and more.  Next to the license plates are some smaller sized vents that let some of the pressure escape around the muffler area and out the back.  When traveling at a high rate of speed I am sure these vents help with the back bumper buffeting around and help get rid of some lift.


One small detail people might miss about the new chassis is where Mitsubishi strengthened it up.  EVO of the past had very bad crash test ratings and this showed in the insurance rates for the EVO and how easy they were to total.  For those who had a sunroof, and stiff suspension installed on their EVO, they may have noticed the creases that started to appear.  I couldn€™t believe this until it started happening on our shop 8. Each side of the car had areas where the body started to buckle!  This is not good. Mitsubishi helped this potential problem on the X with some really slick ribs in the roofline.  These look really cool on the car, and to the passer-by they are hardily noticeable. But they are pronounced enough that a €œCar Guy or Gal€ would see this and know something is up!


No more issues with the roof caving in

While the new chassis design and bracing the X has makes for a better overall platform, it does have a downfall, weight.  The new X weighs about 300lbs more than the old EVO, this means its got some extra work to do to be as fast. It just means it has to have more power.

Last but not least is one thing I really don€™t like about the outside.  The Exhaust tips!  They are not even straight! They are crooked, and just do not fit the back of the car.  These have to go!  Oh ya, and the butt is too plain, it needs something to break it up.  How about a sticker, a PERRIN sticker!


This is an easy category.  They are a perfect wheel for the in stock from.  They are 18€x8.5€ so they can support a 265 pretty easily, and still look stock.  But they are perfect in other ways, that make them €œnot so cool€ that you don€™t want to replace them.  We have fit some 275 wide tires on our EVO with a 9.5€ wide wheel, and it was perfect!  Our JIC magic wheels are on the way!


Just like the body changed drastically so did the engine.  The STI also made a huge change this year, but the engine didn€™t really change much.  For Mitsubishi, the new engine was long over due.  Its not that the 4g63 was a bad engine, but come on, Iron??  Are we living in the 60€™s?  Anyway I love the new engine.  Who cares if some of the things are weaker, or valves are smaller or ports are smaller. These are small details and to 90% of the customers looking at modding this car it will have ZERO effect on the HP they make.  Aluminum blocks are what all modern engine are made from, and plenty of aluminum blocks make 700WHP with no issues. So, to those naysayer€™s out there about the new engine, get back in your Talon and shut it!  Ahhhh, that felt good.  So back to the new 411B motor.  A few tuners have already taken this apart and shown you its guts, and while this is cool, its not something we plan on doing for a long time.  Tuning the stock engine with stock internals is important to see how far this engine can go before things go wrong.


The new engine for those who don€™t know is an all aluminum engine with forged connecting rods and crank. Pistons are a high quality Mahle pistons which should hold big power levels and like the 8/9, these will not be a weak link to increasing power.  Mivec is also a big part of this engine.  Its big competitor has displacement as an advantage to the EVO, and the MIVEC is a big part of how it is just as responsive as the bigger engine.  The wizardry behind the Cams make the turbo spool quicker and keep emissions good and clean.

Pulling off the plastic engine cover, we fine a lot of similar but different things. The fuel rails are the first things that caught my eye as this looked to be the same part as the previous car. Long and flat, these are going to be a restriction for the big power guys.


Also right below the flat fuel rail is a brand new part. MAP sensor, does Mitsu know what these are used for?  I sure hope so as this is a good sign that X€™s ECU has a much better/smarter boost control system.  On the old car the ECU would cut fuel based on MAF readings and RPM.  On this car it for sure is based off of a boost reading of about 26psi.   With good engine management on the way, this is a good sign we have a lot of freedom when playing with boost.


Gone are the belt driven cam gears in place of the newer high tech timing chain.  The chain method provides a much longer service interval and nearly failure free operation. The valves are now pushed down by a cam and bucket, not a rocker arm.  Less parts to add cost, less parts to fail.  Variable cam timing is on both the Intake and Exhaust cam, not just the intake cam like the 9.

While we are still on the head, another thing Mitus improved on was the coil on plug coils. The older EVO used 2 coils and a wasted spark setup.  This means that the coils would fire 2 times per cycle instead of only once.  The new coil on plug setup is great as longer coil charge times can be had, and the coils will have more time to cool down between firings which all means less potential for coils to burn out.


As we work our way down to the bottom, we come across the new pistons, and rods.  Like mentioned before these are high quality forged units.  But the rods are different in that they are shorter.  If you look at the bore and stroke of old and new engines, you will see the older engine had a small bore and long stroke (85mmx 88mm). The new engine is a more €œsquare€ built engine in that is has a shorter stroke and bigger bore (86mmx86mm). This is a better combination for high reving engines, and sure enough the new engine revs 500RPM more than before.  So do I venture to say 8000RPM could be totally doable with an ECU tune??

The block being aluminum is inherently a little weaker(still not weak in my book), but there are a few things that make up for it. The cylinders walls are a semi closed deck style. This means instead of the cylinder walls floating in the tops of the block they are captured by small supports.


Below the forged crank is a girdle. A small but very cool feature found on the X.  The girdle an aluminum piece that bolts to the cranks bearing caps.  This keeps the crank case flex to a minimum.  So far this thing looks like its set to make some big power.

The only bad thing about the new motor is that the Dodge Caliber SRT-4 has nearly the same motor, but bigger displacement.  This relationship with the SRT-4 kind of takes the mighty Mitsubishi down a level for me.

Beyond the engine are the fun things that bolt to it and make power! The turbo on the X is a different than before.  But its not just a bigger turbo, but in fact it has a smaller compressor wheel than previous EVO turbos, but a bigger exhaust housing. At first this may seem like its going to loose spool and make less HP. But remember the turbo is right next to the engine so the exhaust energy helps kick the turbo into motion. So the larger 12cm (vs.10.5cm) exhaust housing makes for some great top end performance.  And in our dyno graphs it shows.

As said before the turbo is located at the back of the engine, not the front.  This makes for a shorter path for the exhaust to get to the back of the car.  But in turn makes for replacing the turbo a little trickier.  While looking at the turbo you may notice the €œChimney€ on top the manifold. If you remember earlier we were talking about that new scoop in the hood, this is what its for.  The scoop blows air over this €œchimney€ evacuating the heat off the turbo and manifold.  A nice clean way to keep engine bay temps at bay.  On thing to take note of is the razors placed all over this area.  The heat shielding is very sharp and in very precarious places that will for sure make for some bloody knuckles.  Be careful!


Finally Mitsubishi got away from drive by cable throttle body. Many are thinking this is worse! Well yes and no. In stock form It can be programmed to make the car feel sluggish, or non responsive. It also can effect overall HP in that is closes right before redline.  But in the hand of tuners, Drive-by-wire throttles are a great thing.  We can change the relation of the pedal to throttle, make it more responsive than if it were a cable.  Also flat foot shifting, launch control, or antilag settings can be had by some tweaking.


Like all other EVO€™s and not like Subarus, the intercooler is in the front, where it should be.  This provides the best, coolest, most consistent charge temps.  But for 08 The routing was totally change.  With the intake and exhaust system being flipped around, the boost routing would also have to be moved.  A clever and simple route for the boost tubes is up and over the radiator.  This is made possible by the new redesigned front end.  With that big shovel type front end, it gives them room to go over the core support.


The intake system for the turbo is just like the older EVO but kicked around and turned a bit.  Now the MAF sensor is a more normal round type with a normal 0-5v sensor. The older system used a Karmen type of sensor,  which is based off of frequency.  These proved to be a little finicky from time to time.   Attached to this is the higher quality EVO MR type aluminum BOV. Gone is the crappy plastic BOV!  But what makes this whole thing strange is the BOV routing.  There€™s like 6ft of tubing going from the boost tube to the BOV!  There are 2 obvious places to tap the BOV into, and where Mitsubishi did it, is not the obvious place.


The air box has the normal front type air scoop to get its fresh air from. But like most all other car, this sucks from a low pressure area.  No ram air intake here!  The filter looks like a real simple thing to install, look for a high flow filter from us to come out real soon.


Now onto the other things that keep the engine rocking, and held back!  Like the older EVO there is still the 100% functional scoops mounted on the passenger side feeding the oil cooler.  Another small but important feature you don€™t find on the Subarus. What is strange is both driver and passenger side grills have a vent, and both have exhaust vents cut into the plastic wheel liner.  So why is there one on the drivers side? Is this for a future tranny cooler??

When we get to the exhaust, we can see that it€™s a much straighter shot to the back of the car.  Less bends, and less piping surely make this a decent exhaust.  Its decent, but not great. Great would be a 3€ SS exhaust and a straight through muffler.  The older EVO had one cat and an 02 sensor after it.  The new €œcat pipe€ actually had 2 cats in one piece.  There is one physical cat, but 2 bricks.  In between these 2 bricks is the 02 sensor.  I know in the EVO world its all about getting rid of the cats.  This is not legal in any state, nor something we condone.   High flow cats are not restrictive, and we see this with all the testing we do. So expect to see the PERRIN €œCat pipe€ with a cat in the pipe€¦..

The rest of the exhaust is 2.25€ tubing with tons of heat shields all over it.  The shields are ok, but they got to go!  Along with this over shielded exhaust, is an over built 02 sensor holder.  I think Mitsubishi could have knocked off $1000, or added NAV for free if they just moved the 02 sensor to the other side of the car.


The muffler section is a little strange in that it€™s a center inlet design, which wouldn€™t be so bad if it entered exactly in the center.  After a few runs on the dyno you can see how it starts to dis-color.  Another strange thing is them muffler section is connected by another flex joint. Why is the question, who knows!


After we got 600miles on the clock we dynoed the car, which really surprised us!  As seen above our muffler got a little color, as did our bumper with the flames we saw!


And the video we did€¦€¦€¦€¦€¦


The Tranny is similar but different.  Its laid out very similar, but with a lot more trickery involved with making the car get around the corners.  We didn€™t invent the S-AWC system, so we are not going to pretend to be experts.  We could just copy down what all the magazines say about it, but the truth is it works.  You point, it steers, simple as that.  The ECU modifies the Throttle, brakes, front/center/rear diffs and makes the car go!  Its nice to know all this cool stuff is happening when going around corners, it makes me want to see what the ECU is actually doing.  Oh wait, I have the Super A-Wack (S-AWC) display!  This is great, while I am going mach 5 around the corners I can watch the Super A-Wack display move around and tell me whats going on.  Seriously, the display is a gimmick, but its cool to see move as you corner hard.

To control the diffs, and apply different TQ to the wheels, the cars uses hydraulics. The pump and reservoir are moved to the back of the car out of the engine bay.  It€™s a great way to take some of the weight off the front of the car and move it to the back.  Mitsu also moved the battery back there for the same reason.


While we are at back of the car, lets look at the suspension. Like the older car, lots of forged aluminum bits.  There is no reason for Mitsubishi to go and change the rear suspension because it worked so well. The same basic multilink design is used, but for some reason they changed out one of the nice aluminum arms for a steel unit. Must have saved them, what, $5? But really not much different here.  There are a couple added braces running from the diff mounting supports, to the subframe, and from the control arm mounts to the subframe.


The front suspension is very similar to the older car, but more boxed in around the rear mount of front lower arm.   Obviously this was done to stiffen up an already rock solid mount. The good news about the front is that our PSRS looks like it will fit!  The old subframe had a huge cut out for the exhaust to pass under and with Mitsu rotating the engine around, this allowed for a stiffer flatter sub frame.  A small but cool detail.


All these little things make the EVO a very solid handling car. The suspension is stiffer than the STI (which is good and bad), and the steering rack ratio is a lot faster so it takes less input to make it around the corners.  The rack is the one thing Subaru should have taken note on a long time ago.  WTF Subaru?  Oh wait, this article is about how cool the EVO is€¦..


The interior doesn€™t have a lot to say other than, Finally!  Finally the interior better fits the cost of the car.  Almost every inch of the car got revamped.  If we look at the old car, every piece of the X is better.  Better finish, better materials, better fit, better everything.  But, here comes the but, its still not up to par with the Subaru or some of the Euro cars.  There are definitely things left to be desired about the interior. For me, it€™s the steering wheel, and textures on the plastic controls.  And where€™s the telescoping wheel? The STI has this and makes for a great seating position for us tall dudes. But I think what makes up for all the interior issues for me is the seats!  Like previous EVO€™s the seats are perfect!  Even the little fake carbon headrest trim is kind of cool.

There is one more thing that is a step down in the controls department.  The Shifter. It used to be super solid, super smooth, and nearly perfect. But now its clunky and almost hard to drive smoothly. I hope that as time passes it get better, but at this point with 800 miles on the clock it is far behind the STI in shifter quality.


Oh one more thing.  The clutch.  Its way different than the other cars around the shop, and almost weak feeling.  Maybe Mitsu used too tight of a restirctor in the hydraulic lines. This could be a problem once we start going to the track and doing some launches. But who knows we will see!

Ok fine, one more  thing. The trunk!  If you get Fosgate Stereo like we did, you quickly find that the trunk is a little tight. I am sure you can cram a golf bag or dead body can fit back there, but neither of those things are items i plan on putting back there.   This is an area where Mitsu cheesed out on. The carpet, the trim pieces that cover up the floor boars are pretty cheap looking.  Its like they went down to the craft store and the Depot and make a floor.  While we are talking about the trunk.  Also the window washer is back there but located in a spot that is going to be very hard to fill. Esspecially when we put our Water injection system on the car.


At this point the EVO X doesn€™t have the Ralliart to compare to like the WRX.  It seems that when we were commenting on the STI vs WRX, it was easy to look at the things Subaru did to distinguish the 2 cars.  Hopefully Mitsubishi doesn€™t have to many distinguishing features from the X to the Ralliart model, the more they keep it looking like the EVO X, the better.  My guess for Mitsu to get the price down to the $24K range, the wing, wheels, brakes, seats and some of the aluminum suspension bits will be gone. While this does suck, it€™s the only way to knock off $10K of the price.

The X is a great car, and seeing and driving one in person makes me want to get rid of our families 08 WRX and get EVO, but then the dogs won€™t fit in the back.  That is a perfect setup, STI and an EVO in the garage.   I just have to figure out how to make that work€¦€¦

If there was one thing I could change about the EVO is€¦€¦€¦€¦€¦. The engine.  It needs .5 more liters to be a real competitor!!   J

With the acronyms the 08 Mitsubishi Lancer Evolution Ten has, AYC, S-AWC, S-Sport, ACD, ABS MR, 4B11, PS, DSG, MP3, ASC, GPS, TC-SST, its interesting how all these things can be scribed in one simple letter€¦€¦X


 Posted by on March 8, 2008 New Cars Exposed Tagged with: , , ,
Feb 112008

We were the first to dyno the 08 STI, we were the first to bring you intimate pics of the car, and we were the first to tune the AccessPORT on the STI!  In stage 1 form (bone stock car), with some initial testing we did, we got great gains!  We saw roughly 40ft-lbs and 35WHP with nothing other than an ECU reflash!  Its not very often that you can get those types of gains from a bolt on/flash on.

Stock ECU tune vs. PERRIN Stage 1 Tune

This graph shows our initial dyno plots vs. our initial Stage 1 tuning.  The above graph was release a long time ago, when we were doing a lot of testing on the car.  With quite a bit more road/dyno time under our belt it was time to go to the next level!  Stage 2, the stage that 90% of the STI community will be stepping up to after they buy their car.

Stage 2 for most companies consists of a Turboback 3€ exhaust.  This is true for the PERRIN stage 2, but with a little twist.  Our Stage 2 down pipe consists of (2) cats, where most companies have (1) or no cats.  For legal reasons we build our downpipes with cats to keep the EPA has happy as possible.  Many people think that cats are restrictive, but this really isn€™t the case when dealing with less than 400WHP.    We will show you the huge HP you can gain with (2) cats.

Before we can got tuning a stage 2 car we need an exhaust.  Ok, simple!  We have (2) types of exhaust we are working on, one that fits to the OEM exhaust pieces (so you can buy just a muffler or just midpipe) and another that is a complete catback, that is all inclusive and a little simpler.  We have shown the prototype OEM fitment system before a few times. But here it is to refresh your memory.

PERRIN Muffler bolted to OEM midpipe.

Dual Single Tip€™s for this system.  This tied to our 3€ midpipe is a great sounding exhaust.

But for this test we will be dynoing our car with our 3€ system that doesn€™t interchange to the OEM pieces.  Of course it still bolts to the stock downpipe.  It consists of the same basic 3€ piping, resonator, and muffler.  The muffler has a central chamber where the exhaust splits into a 3€ core.  Both the above and below systems have a similar design, one is just a different entry.

This shows the central entry of the 3€ tube into the muffler

Up close shot of the 4€ dual Single wall tip

A shot from the back showing the tips and the straighter shot of the 3€ piping to the back of the car.

This the first shot of the exhaust we have posted up, so feel free to critique us with suggestions of tips or other things.  Like our other current systems this will be available in a black thermal coating.

The rest of the €œturboback€ exhaust consists of our off the shelf downpipes with cats.  The cats are high flow, metallic core cat, like we have been using for quite some time.  Before we go and dyno the parts and start to tune our stage 2 setup we tested our latest version of our stage 1 map we have building/tweaking.

Preliminary PERRIN Stage 1 results, vs the most current Stage 1 results.

The above graph shows our first iteration of the 2008 STI stage 1 mapping. This was a huge gain over stock and with some tweeking we did with more agressive boost control and some Exhaust cam changes we netted an additional 15-20ft-lbs of torque at lower RPMS.  This mapping represents the 92/93 octane maps that we will be sending out to our customers that buy our custom map program and AccessPORTs.

So we as quick as we could, we yanked the OEM exhaust off the car and installed the newest version of our 3€ catback exhaust.   Like our other exhaust this fits to the OEM down pipes.  With the coolant still above 160 degrees we did a few quick runs back to back.  With other catback exhaust testing we did, we would see about 8-12 WHP, with doing no other mods

PERRIN 3€ catback exhaust test on 2008 STI using stage 1 mapping.

What is different about this test is we left the stage 1 tune on the ECU.  So its running a little leaner, little more boost, and more timing that it would be instock form.   Just for fun we flashed the ECU with the stock programming before and after the catback.  The results reminded us why the reflash was so important.  The inconsistencies and rough graphs didn€™t give us any proof of the exhaust doing anything.  With our Stage 1 reflash(which fixes many of the OEM ECU tunings shortcomings) and the catback exhaust installed, the runs were very consistent and consistently showed a 10WHP gain.

Next up is the downpipes!  As we have explained before, our downpipes replace the stock (2) cats with 2 high flow cats.  While this is not the normal type of downpipe you will find, we will show you how you can make lots of power and still be legal.

This is the graph of the HP and TQ gained  from PERRN Dual cat downpipe being added to the catback.

This is the graph of the HP and TQ gained  from PERRN Dual cat Turbo back exhaust System

These graphs are showing the gains had by installing the downpipes and the catback.  Again we are using the mapping from the Stage 1 setup we did.  You can see that the Catback and both downpipes are about a 10WHP each, making 20WHP.  This is with NO retuning done and the same boost levels.  The torque went way up because the turbo spooled up quicker by a couple hundered RPM.  Now lets do some more tuning and see what we get!

This graph shows the HP we got with just bolting on the Turbo back and the HP we got with further ECU tuning.

The results with further tuning with the complete Turboback exhaust are amazing!  Before the ECU didn€™t like any additional timing up top, now with the freer flowing exhaust the engine was much less prone to knock and liked to run a little leaner. The leaner mixture, and additional timing up top is very noticeable, and no longer does the car feel like it totally falls flat on its face above 5500rpm.

This is our Stage 1 results vs. our stage 2 results.

While our Stage 1 results we very impressive over stock at 35ft-lbs and 30WHP, Stage 2 takes the cake!  For under $1500 you can take your Stage 1 2008 STI and turn it into a Stage 2 monster with another 50ft-lbs and 35WHP.  Not to mention a sweet new sound!

This is the stock 08 STI results vs Stage 2 results.  Don€™t forget this is with 2 cats!

This the stock 2008 STI Horsepowrer and TQ results we got the day we started tuning our Stage 1 setup.  For under $2000 in parts, you will find very similar results on your 2008 STI.


There are 3 important things to note on the results.  One is this is all done on Oregon 92 octane fuel, Two is we used our dual cat down pipes, same as the ones we sell, and three all runs were done in the manor as before.  This means same gear, same start RPM, same load time, and same run time.  We just want to be clear about how the results were obtained.

Other important things are the HP gained from our Exhaust system installations. The catback exhaust was worth about 10WHP and 10ft-lbs of torque, the turbo back was worth about 20WHP and 30ft-lbs or torque.  This is with out any ECU tuning.

Add in the AccessPORT to those numbers and add another 20WHP and 20ft-lbs of torque. This makes for an incredible 35WHP and 50ft-lbs of TQ gained over Stage 1, and a crazy 60WHP and 80ft-lbs of torque over a stock car!  Look for our Stage 2 setup to be under $2000, which includes the exact same parts as are tested here, plus the AccessPORT.

Like we did with our other Stage 1 STI mapping, we will do some minor tweaks over the next few days after we beat on the car a bit more.  Stage 2 for us is important, as this is the most popular setup for the Subaru enthusiast.

We feel this is where most people go with their cars, exhaust system, and ECU flash and they call it good.  Because this is such a popular setup, expect a lot of refinement.  So what is next up on our plate?  Stage 3 of course.  We will be doing both TMIC and FMIC mapping and proving, along with water injection maps.

Finally this car feels fun to drive!


 Posted by on February 11, 2008 Dyno Test & Tune, ECU Tuning, Project Builds Tagged with: , , , , ,
Feb 082008

We were very lucky to get our hands on the first STI available in Oregon, and maybe anywhere in the US.  Our dealer was very reluctant to sell us the car as it was not offically released.  After we dynoed it in stock form with in hours of owning the car, we very quickly shipped the ECU out to COBB next day air.  They needed the ECU for only a few hours and we got it back in 2 days along with some special cables and a funny grey box……… what are these for??


Along with this specially programed AccessPORT we got a specail version of the Protuner software.  After a few minutes of studying the new maps, and layout, we were ready to tune!  This would be a stage 1 base tune on a car with about 100 miles on the clock.  Yes, we know, this isn’t the normal break-in procedure, but my belief is break it in loose!


How do we make more power?  More boost is one thing!  The stock boost curve seems to hold a little better than years past, this could be from the different turbo.  At this point who knows if it is bigger or smaller than past STI turbos.  In time we will dig further into the car discover what the difference really is.


In stage 1 form (bone stock car), the initial testing we did, we got great gains!  We changed the AFR targets, timing and boost to get a healthy 40ft-lbs and 35WHP with nothing other than an ECU reflash.  Just wait until we get to the stage 2 parts and tuning.  Keep an eye out on more results soon!

Quick Update!!!!!

Before we went and installed more of our parts to build the stage 2 setup, we did a few more tweaks to the boost and Exhaust AVCS and gained a little more power and torque!

PERRIN Stage 1 initial tuning vs. PERRIN Stage 1 final Tune

Here is the retune vs. OEM programming.



 Posted by on February 8, 2008 Dyno Test & Tune, ECU Tuning Tagged with: , , , , ,
Jan 122008

I learned a few things from my vaction in Maui.  If you dont own a GM product, you must live there, Gas is $4.10 for premium, Mike D from GreenDay shops at the ABC stores, WRX/STI are very rare, Legacys do not exist, Chevy Cobalts have launch control,(good for make it actualy go fast), only 1 road with 55mph limit, all the rest were 35 or 25, and Poi is nasty!

After 10 days off, its time to get back to work!  While we made a good first impression with the tuning we did on our STI, Cobb Released the 08 WRX AP’s and it was time to start selling them!  We could just simply sell them with the base Cobb Maps, but that is no fun!  After playing catch up all week, Saturday was my first free day, and here is what i did!

To make things clear as to how we tested our 2008 WRX sedan (yes, not the hatchback, its definately not stock).  We are using the same Dynapack as we always use, using the same basic settings as we always do on Subarus.  The runs were 14 seconds long, 3 seconds of launch, and on this car its done in 3rd gear.  3rd gear takes the car to 100+MPH so it works great.

Our base runs we did showed a peak of 210WHP and 245ft-lbs of tq.  I thought this seemed a little high.  High enough i had to go back on the internet to see what Subaru rated the 08 WRX in HP and TQ.  No its the same, 224HP and 226ft-lbs at 2800 RPM. Did Subaru under rate this car?  Given the WHP and TQ we saw, if you compare it to our STI’s base readings, it makes the STI’s 245WHP and 275ft-lbs not look so good.  With all the dyno numbers we have seen on stock STIs (rated at 300HP) The 245WHP range has been exceptable as equaling 300 engine HP.  So if 240-ish means 300 engine HP, what does, 210WHP mean in engine HP?? Surely not 224HP!

dyno_tune_08stistart Graph showing our 08 STI in stock form and with stage1 mapping.  The relationship of stock HP ratings vs. WHP ratings makes sense on this car.


Back to the Stage 1 08 WRX results.  The lower HP graphs are what we got from the stock car, on the stock ECU.  As i described above, this is very high for a WRX only rated at 224 engine HP.  Running at 12psi peak dropping to 8psi at redline.  The runs were very consistent. After an ECU reset to ensure things were ok and running smoothy, the base HP runs were established.  Unlike the STI the WRX runs very well in stock form.  Like most of the newer Subaru engines, the ECU runs 14.5 AFR while on boost, up to about 3300RPM.  This seems very dangerous, but obviously it works fine for low boost levels, and is done for emissions reasons.  ZERO knock was heard, ZERO timing retard was seen, it ran very very well.  Smooth, maybe not, but that is where we can come into play.

08wrxresults Graph showing Stock 08 WRX, Cobb Stage 1 mapping, and PERRIN Stage 1 mapping.  Which version would you drive?


We first flashed the ECU with Cobb’s Stage 1 map.  Boost went up to 15psi, and tapered back down to 8-9-is at redline.  The increase in boost at peak torque (3500RPM) made for an extra 20ft-lbs of torque, and 25WHP at 3500.  As you can see, power at redline didn’t change, because the boost was the same.

Now it was time to play!  With some AVCS tweaking, adding a little more boost, changing boost response, you see what kind of results we got!  At 3000 RPM, 65ft-lbs of torque over stock mapping, and at the same point we made 35 extra HP.  The biggest gain we got was at lower RPM where the tiny WRX turbo is happy.  At upper RPM, the turbo shows its small nature.  The boost drops off after 4000 RPM and there is nothing you can do about it.

Next is Stage 2 tuning.  With a free flowing turbo back exhaust, i think there is quite a bit left to get out of this engine. Mabye not at redline, but from 2000-4500RPMS there should be lots of room!

Look for intercooler, and Turbo back results with mapping soon!



 Posted by on January 12, 2008 Dyno Test & Tune Tagged with: , , , ,
Dec 182007

There is not much to brag about, but, now that i have your attention, lets see what these new STI’s put down!


The first couple runs showed about what we would expect to see. Most STI’s put down about 230-240WHP, and we were right there. Same with torque, we were pretty close to what everyone sees.

Few things to note, redline is 6500, not 7000. WHAT?? Well that is simple, Subaru only needed to make the 305HP mark and it doesn’t need to go the extra 500 RPM to get there. If you look at other peoples dyno plots on a stock car they peak around 6000RPM. I am not saying that it can get some more power, or better shift points raising the redline, but that is my guess why Subaru did that.

We have 92 octane here, and as many know the stock ECU programing loves race fuel, higher octanes, and water injection. Water injection is definitely something we are incorporating in our futures plans with this car. You will notice on the graphs that there are 2 lines. 11 of the 15 runs were just like the lower HP line. This is what we are using as our base power and tq numbers. The other 4 runs were where the ECU was happy, and was running zero knock retard and adding a couple degrees. These runs only happened right after we turned the ignition off, and did a run.

With the 15 runs we did, we tested the I-drive stuff out. Like in the LGT spec-b, it does effect how the car feels, but does it effect power?? Not a single bit! I expected differences in low end power, but nothing! Boost was the same, power, tq, boring!! The only thing I-drive does is change the throttle position vs. the accelerator position. Which does effect low end power, but only in normal driving conditions. When it comes time to tune these, being able to change maps with the poke and twist of a button will be very cool.

We tried Deltadash to see if we could log some data, and to my surprise it worked, and showed the one thing i was most interested in. The Exhaust AVCS! Not that everyone knows, but the new 2008 STI has AVCS on both the intake and Exhaust cams. The intake is advaced at lower RPM and load, but turned off at higher RPM and load. The AVCS for the Exhaust cam is a little different, it is not advanced, but retarded. Under load, the Ext cam is retard the whole time, ranging from 20 at low and increases to 30 in the midrange, then back to 20. The only time it goes to zero is under normal driving. The question is, when we can tune this, where will it help make more power?

Just to make things clear, this is totally stock with a whopping 40 miles on the clock. We went from the dealer, took an hour drive, and rolled right up to the dyno. A little history on the Dynapack and how it is setup. Many people run the cars in 4th gear, at for 12 seconds. Because of our big plans with this car, we started in 5th gear, and run it for 14 seconds. Both of these factors play into the actual HP and TQ numbers by lowering them. We could have made the dyno read a bit higher, by changing to 4th gear, or making the run shorter, but for tuning purposes, and future part comparos, this is what we decided on.

I know you all are thinking, shut up and give us more data and pictures! We just got the car a few hours ago! What more can you expect!

Look for lots of info tomorrow!









 Posted by on December 18, 2007 Dyno Test & Tune, ECU Tuning Tagged with: , , , , ,
Dec 162007

So I am just sitting there responding to some NASIOC posts, and I get the call…… “Your 2008 STI is here!!!” our good buddy at our dealer tells me.  This was a huge surprise to us as we had all been told they would be in by the end of January!  It’s December, and we already got our car.  Time to get to work!


When ever we get a new car, the first thing we do is go over all the new things, and changes done from the previous models, and in this case from the WRX.  For us, getting a new model of a car, is like opening Christmas presents. First off, from the WRX, this car is very different.  They may share a few of the same parts, like the chassis, and dash, but that is where similarities end.  With our STI came a very “Mini Cooper” type of media pack.  Magazines, brochures, tattoo, kill markers, listing of all Subaru clubs…….



The obvious changes are the flares.  2007 and previous model WRX’s had the very distinguished wheel well bulges.  So when the 2008 WRX came out with little to no bulge, I was a little disappointed.  One of the more distinguishing features of the WRX/STI was taken away.   Anyone else who feels the same, should go look at a 2008 STI, you will not be disappointed!


Subaru took their race-car-like bulge to the next level. There is roughly 2″ more fender flare on the STI vs. the WRX.  When looking them both side by side, this is very noticeable and makes the WRX look more “relaxed” and more of a grocery getter!


To incorporate the flairs into the rest of the body, Subaru beefed up the front bumper and left the flair open where it meets the door.  The open vent at the door really adds to the race car look, and makes is much more aggressive.


The front bumpers are wider and the lower intake is much more open looking.  I say looking because of the black colored part of the plastic.  The black part is just asking for us to cut it out for a front mounted intercooler.  This contrasting black plastic is carried around to the fog light area to an even more aggressive look to the car.  If you have seen the pics of the prototype WRC STI, you will see similar type styling.




Other than the flares the STI has a larger wing than the WRX.  It’s rather the same shape just longer and with some raised sides.  This is better looking than the WRX, but still could use some improvements. We have a few things up our sleeve that should bring this part of the car back to life!


Right below the wing is that really bad looking, or normally bad looking Chrome panel. On the STI this part is not chrome, but color matched to the body, a huge improvement over the WRX hatch.  This removal of chrome was continued to the front grill. This was one of the biggest things people complained about when the 08 WRX debuted.




The scoop for the STI model is unchanged from the WRX.  In the past Subaru has always stuck a larger scoop on the STI to go with the larger intercoolers that came on them. But the last couple models have kept the same size scoop. The scoop is actually very large, but it’s a little deceiving until you get right down and look at it.  When we show customers our WRX or STI, its one of the things people talk about.  No more snow shovel to try to look over while driving, just a nice bulge.


One thing that I didn’t pick up on right away is the badges.  STI has always been pink, but on the 08, they are red!  I didn’t notice this at first because our car is white, and from far away, red and white make pink.


Again, Subaru is making it more appealing to more people.  But they still kept the STI pink in some places.



In a quick glance, nothing has change.  Take a second look and you will find all the little things that are different.

Starting from left to right the first thing is the intake system. The intake has the newer smaller Denso MAF sensor, and Legacy type intake air box.  Both these items were the same as found on the WRX, but the difference is in the silencer.  When we first pulled apart the 2008 WRX, I noticed the air box was the same as the Legacy, but no silencer. In fact it had the place to snap one in, but the hole was blocked off.  The STI has the silencer!  Not sure why but I guess to make the engine quieter. Just like the Legacy platform, the power steering reservoir, and ABS is moved back to the shock tower.  Subaru relocated the boost control solenoid from the shock tower to the top of the intake manifold. This is a very distinguishing part of the 2008 STI. The solenoid is covered by/held on by a nicely formed steel shroud.


The intercooler looks to be similar to ones found on the older STI’s but with no STI logo painted on the face.  Actually it’s quite a bit larger than the previous STI IC.  The new STI intercooler has a bracket that now bolts to the head, instead of the block, which allows the IC to stretch further over the turbo.  This newer wider IC fits the wider opening of the hood scoop and definitely makes better use (compared to the WRX) of the air traveling through the scoop.  While the PERRIN WRX TMIC fits right now, this gives us some more freedom to make an even Bigger Intercooler! The turbo that this new TMIC covers up is not labeled like other turbos.  Is it a VF40, 39, 43, who knows, we will have to pull it off to discover the exact size. But base on our initial dyno numbers we saw, its not much different than the previous STI turbo.

Just like the 2008 WRX, the STI engine has the secondary air pump installed.  Some may be thinking that has to go!  This is a great way for Subaru to keep their engines within the emissions guidelines with out having to cut back on power. So be happy its there and that your engine makes 305HP!  The Other strange thing is the fuel system. Its looks pretty similar, but the fuel pressure regulator has moved to the shock tower.   Not only that, but the feed and return line feed into the regulator. It’s sort of a balanced fuel system.   I am sure Subaru did this to make it close to a return less system but not a return less system.  This setup will minimize fuel traveling through the rail and heating up, then traveling back to the tank. Hot fuel is bad for a couple reasons, and anyone who has been on the dyno with no gas in the tank can contest how hot fuel gets, and how it hurts power.


After that there is nothing else really visible under the hood.  But wait there is something you can’t see, and this is a very annoying part to be missing.  The AC belt has no tensioner on it!  What?  I discovered this on the WRX when I went to throw on a PERRIN crank pulley on the engine.  Then I noticed there was No AC tensioner.  There must be something we can do about this, but it will have to wait.   Other than that that is all the visible things in the engine bay.  Well there is something you can kind of see…..


The one thing about the 2008 STI that will either make this engine the best engine Subaru has ever made, or make it the 2ndmost complicated (behind the Ez30R) is the Dual AVCS.  Not only does the ECU change the timing of the intake cam depending on load, but now it can change the exhaust cam!  This could be very cool!  I am sure Subaru says they did it for emissions, and blah, blah, blah, but what will it do for tuning? We have seen what varying the cams can do for turbo spool up (decrease the lag time), but what can changing the Exhaust cam timing do?  This is something we will have to wait and see.  From our initial dyno testing, and data logging using the DeltaDash, the Exhaust cam is being retarded. Which when teamed with an advancing intake cam, this can create more valve overlap.  Normally this is good in NA high revving engines, and bad for boosted engines. But who knows what it will do for power or spool, we will just have to wait until we can tune the ECU.


If anyone has looked at the last few STI engines Subaru has made, they have seen the lower part of the head, with the blanked out fittings for a sensor to go. Well now there is finally something filling the hole!  And now both the top and bottom of the cam covers have bulges! A small but interesting difference from the WRX to the STI is the STI has an oil cooler/warmer where the WRX did away with this.  The 2008 WRX is the first turbo Subaru engine to not use an oil cooler in a very long time.  Obvious, this was a way to cut some cost out of the car on the WRX.


The HP specs on the engine are a little different than previous STI’s.  The past STI models (2004-2006) were rated at 300 engine HP and 300ft-lbs of torque.  The 2008 is rated at 305 engine HP and 290 ft-lbs of torque.  So why the change?  This has to do with the SAE ratings that changed a while back.  The 2007 STI was rated at 293HP and 290ft-lbs of torque. So Subaru has added some power, and kept the same peak torque but lower the RPM at which it hits 290ft-lbs.  But I think there is a little more to the story.  I think Subaru underrated the 2007 STI with the new SAE specs in place.  In late 2005 a new SAE HP correction was put in place and while this caused some cars manufactures engine HP ratings to drop, some increased. Subaru’s HP numbers stayed the same, but when the 2007 model year STI, (first batch of Subaru’s affected by this change) the numbers dropped, to the 293/290.  What is strange, is that many people were finding the 2007 STI was making more power than before! Not a lot but 10-20 more HP than previous cars, and with a lower HP, that seems kind of strange??  Hmmm, now for 2008 they claim more HP and same torque at a lower RPM, but with less working RPM?  Seems like they might have kept the same power, as the previous year and cut back the Redline.  Who, knows, but it is strange.


The Exhaust is again similar but different than the WRX exhaust. Similar in that it’s a tube that goes from the front of the car to back, and bolts to flange on the muffler.  They both have transverse mounted mufflers, but that is where things start to change.  The STI steps up the diameter of the exhaust, and gets rid of the funny shaped center mounted resonator for a normal round type. The muffler is similar to the WRX, but the obvious change is the tips. The STI has a new distinct look, kind of Euro, kind of BMW like dual twin tips.


The muffler is about the same size, but with the different tip configuration.  The larger piping, different resonator, and tip configuration make for a nice change in the exhaust note.



The big suspension change was done with the release of the 2008 WRX and now the STI takes it a step further.  Like the Engine if you take a quick glance under the car and it doesn’t look a whole lot different, but in fact there are a few very important differences to note. Starting from the front of car, the STI suspension is laid out just like the 08 WRX, and previous Legacy models.  No lower subframe and the vertical control arm bushings are there.  The control arms are the forge aluminum type similar to what was installed on the Legacy Spec-B. The front swaybar is just like every other Subaru out there, 20mm.


Nothing other than that to take note of, other than some funny looking engine mounts.  Subaru claimed that the 2008 WRX engine and tranny were lowered roughly .5″ over older Impreza’s. While this might be true on the WRX, it is very noticeable on the STI.  The front engine motor mounts are noticeably flatter, looking as though they had been smashed in a 100 ton press.  Also gone are the cheap, rubbery plastic engine mounts.  Moving back toward the tranny, we find the same thing.  The tranny mount was also shorter than before. Besides lowering the center of gravity the lower mounts make the engine and tranny stiffer, providing a better transmission of power from the engine to the wheels.  And like the other STI tranny mounts, its solid across the middle of it.


Just like the 2007 STI the 2008 STI has taller gear ratios for the 2nd, 3rd, and 4th gears.  In the 2007 STI this was a noticeable change and made for a better delivery of the power across the entire speed range of the car.  The clutch is the same nice and smoother engaging clutch of the past.  We will soon find out how much torque it can hold!  The shifter seems shorter than I remember, but this could be because I was used to the longer stock WRX SS I had been driving lately.  Still in my opinion, the height of the knob seems too short, but I am tall guy, so shorter shifters are not something i have ever liked. Shorter throw, now that is a different story.   Since the WRX came out, I always thought that it needed to be a couple inches taller.  One strange thing with the tranny is the dipstick is gone!  Now in its place is a Socket cap screw plugging the hole.  So where did it go?  The dip stick altogether is gone, and now has the more normal side fill plug.  For those of us who do our own service, this is not going to be as easy as it once was to change the tranny oil.

As we get to the back of the car, again the suspension is similar to the WRX, but a couple things are different.  One is the differential cradle. The cradle on the WRX is a steel formed piece, and like other STI parts, its aluminum and a bit lighter.  The other thing about the rear suspension is the swaybar is bigger. The WRX uses a 15mm and the STI has an 18mm. Overall this seems small compared to the older cars, but because of the way the swaybar, is designed, this has a greater overall stiffness than the 19mm bars of the past.


The Suspension bushing and rear subframe bushings seem a little stiffer, but it will take some part number cross referencing to figure this out.

Last but not least, the wheel and tires.  The wheels are huge for the STI.  Wheels are 18×8.5″ with a 55 offset. The older STI wheels were 17×7.5, and later changed to 17×8.  The largest tire that came on previous STI’s was a 235, and now they have monster wide 245!  Like other changes to the STI, Subaru picked a more subdued tire.  Gone is the super sticky Potneza for a Dunlop with a tread wear rating of 300.  Some magazines have done some skid pad tests and shown a slight drop in lateral G’s on the 08, which is most likely from change in tires.  While the 08 STI has a lower lateral G rating, it has shown to be faster in the slalom and faster around the track.   To us and others reading this article, I am sure we are thinking the same thing. Who cares what it comes with, how big of a tire can we go!  With stock 8.5 wheels, 265 should be no problem, but what about a 295?  With the right width and offset, I think 295s will be common.  Imagine the grip the STI will have with some 295 Yoko Advan A048′s.  That will be scary!


More refinements on found on the insides of the STI.  The first thing you will notice is the seats and carpet, are not blue anymore, but a better grey color.  Subaru is again, trying to make their cars more appealing to everyone, and getting away from the blue is one to get the older crowd interested in the car.  The seats also get better bolsters than the older STI.  I as well as many others hated the past STI seats.  They were too flat, too hard, no bolsters.  The WRX seats were better than the STI seats!


The next most noticeable item is the center console. It’s more Legacy like, with nicer buttons, trim and the cool sliding door that covers up the cup holders.  Located on the center console is the buttons for the center diff control and I-drive functions.  The Diff control of the past was simple. There was an auto mode, and a knob to put more power to the back or front, which also allowed you to lock the diff, or leave it open.  The 08 STI has all these same features, but adds a DIFF plus and DIFF Minus setting for gravel specific, and tarmac specific settings.  And instead of the Radio Shack type roller switch, it’s a silver, luxury car type of switch.  Taking the similar styling note from the older STI, the new one has a more drastic approach to the shifter trim ring.  Previous STI’s simply took the WRX console and bolted on a ring.  Now its whole different plastic console piece compared to the WRX.  Also right above it a perfect Cell phone holder.  The WRX has a similar spot, but no rubber mat. So your phone or garage door opener just slides around, and annoys the hell out of you!


Onto the dash.  I had been driving the 08 WRX for a long time, and come to love the layout of the dash, the quality of the gauges and seating postion. Again, the STI goes a step further with the gauges, and HVAC controls.  The lighting of the dash I a little different, as is the HVAC controls.  The small bits of silver add to a nicer, more quality look to the interior.  To the left of the dash are the mirror controls, headlight leveling system, and the DSC button.  This is all similar to the WRX, except that the DSC has 2 modes.  Normally it controls both traction, and yaw or rotation of the car.  Traction control is handled by closing the throttle, and the yaw is controlled by applying the brakes.   Hit it once and both are turned off, and the DSC light turns orange. But hold it down the DSC light turns green.  This second mode does away with the traction control and keeps the yaw control in place. This mode is what most likely will be preferred for track or auto crossing.  So now if the tires slip, the ABS unit will start to apply force to the brakes, and not cut power to the engine.


The rest of the interior is about the same, but with the new grey Alcantara patched in here and there.  The seating room is the same, the trunk room is the same, speaking of the trunk, gone is the Intercooler sprayer tank.  Subaru didn’t include this in the 08 STI, which is a bummer, but it just gives us another reason to create our own tank for our water injection system.  There is a little more plastic on the doors than I would like but its Subaru not a Porsche!


Many people are complaining about how expensive the STI is this year.  The price for the base STI did go up $1000, but there is more than a $1000 in parts.  18 wheels, 245 wide tires, 2 stage DSC, New Center diff settings, Lower engine and drive train, more powerful engine, nicer interior, better seating position, telescoping steering wheel, wider track, shorter body, cool hatchback shape, and the flares all make it worth way more than $1000. Not to mention than this STI has the most potential for power and handling compared to previous STI’s.

Subaru did leave some things to be desired, but of course, no car is perfect. That is why the term “aftermarket parts” exist!

What are our plans for the STI?

We have 2 big tricks up our sleeve, things that no one else has ever done before! Besides that, there are the normal things to expect.  Turbo back exhausts, intakes, intercoolers, shifters, bushings, swaybars, endlinks, PSRS, and the most important item we plan on offering is Custom AccessPORT maps for all stages of tune.  As you are reading this, we are the first to have, and are already tuning our STI.  We are the first, and we are the ones leading the pack.  There are many exciting things in the next few months you will see from us!



















 Posted by on December 16, 2007 About Your Car, New Cars Exposed Tagged with: , , ,
Nov 172007

Now that Project $15k has a healthy dose of power it’s time to put some focus on the suspension and brakes.


Starting with a car that has 110k miles on it probably means it has the original struts holding things together but not playing a big part in the suspension game any more.  We found this to be the case as they where worn out, rusty and leaking.  The springs have been changed in the past with some cool looking orange units.  Since we liked the ride height we will continue using these springs in the build to save some cost in that department.

So all that had to be done was swap in the new struts and clean things up a bit.  We started in the rear and found that one of the last owners put in 2006 model WRX lowering springs, we know this because they also put in 2006 model strut tops.  This is not a necessary thing but it does give us fresh rubber in the strut top bushing, a good thing.  The installation of the struts was very easy and straight forward.  One benefit we got from replacing the struts and doing some cleaning was that the car lost about 5lbs of dirt!  Not kidding, once I was done I swept the dirt into a big pile to take a picture but before I could my shop guys swept it up (dam clean freaks!)

The struts we chose are Tokico Spec D.  We chose these as a comprimise of price and performance.  This was a $10k car and I dont see the need to put 10%-15% of the vehicles value into struts, but they where still the second most expensive modification. ($530.00)

“TOKICO€™s D-Spec Series adjustable shock is a multi-use product that€™s the result of sophisticated piston and valving design. In addition, it utilizes a unique variable-aperture bypass, which is controlled by an adjustable slide valve.

D-Spec (damping specific) adjustments change both rebound and compression damping simultaneously. Between maximum soft and hard settings, the D-Spec is infinitely adjustable. For more information and to view the damping graph full size, click here.

D-Spec shocks and struts are sold in sets of four. Each set includes a manual explaining the adjustment process as well as covering suspension tuning tips.”


I could have gotten away with  just a thorough bleed job and a good brake pad but the original brake lines where probably getting a little worn by the elements and getting soft or brittle and the rotors where showing some wear grooves and the center hats where rusty.

I went ahead and installed new StopTech replacement slotted rotors that look cool with the black painted center hats, StopTech SS lines and Axxis Ultimate Brake Pads.  For brake fluid I just chose Prestone DOT4/DOT3 as again this is a budget build that will mostly see street driving so an expensive racing fluid is not needed.



 Posted by on November 17, 2007 Project Builds Tagged with: ,