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Andrew's 2008 STI - GTX3076 on E85 - 505whp!

Posted by Ed Susman on

Here is a build we did recently that ended up with more power than expected... another one in the 500whp club!

This car came to us running a basic stage 2 package with about 90k miles on the clock. The customer wanted a big bump in power while maintaining the streetability and reliability. So we went over all the options and spec'd out the following setup:

IAG Stage 3 Tuff Closed Deck Shortblock
BC Stage 2 Cams
BC Valve Spring Kit
Refreshed heads with performance valve job and bowl blend
IAG 1/2" Head Studs
IAG TGV Deletes
Tomei ELH + UP
Invidia DP, Q300 CB
ATP Stock Location GTX3076 Turbo
Tial 44mm EWG
Perrin 3" Turbo Inlet
Process West TMIC
TurboSmart Kompact BPV
Cobb SF Intake with Box
Company 23 Anti-Surge Boost Control Solenoid
OMNI Subaru 4 BAR MAP Sensor
Injector Dynamics 1300cc Injectors
Walbro 450lph Fuel Pump
EQT Fuel Pump Controller
Cobb Flex Fuel Kit + Fuel Pressure Sensor Kit
Cobb Fuel Pressure Regulator Kit
Cobb AP V3
RPS MAX Series Clutch with Street Disc
EQT Custom Flex Fuel Tune

After we built the car, the customer completed the break-in mileage. Then it was time for tuning. Since we had a nice strong block, we could really push this turbo and see what it can do all out. We started with 91 Octane and made around 350whp at 21psi.... not bad! Then we moved on to E85 and really let her rip. This turbo loves boost and just kept making more and more power. We ended up hitting right at 30psi in the mid range, tapering to 28psi by redline. The 1300cc injectors were absolutely maxed out at this level and the turbo was all out of flow up top as well. But we still managed to just crack 500whp along with a really nice wide powerband! And all that on a TMIC. The turbo could make more boost and torque in the mid range, but we opted to keep things somewhat reasonable and linear.

The car absolutely rips in any gear and just about any RPM. The best part is that it looks completely stock and sounds very mild. This is a true 500whp sleeper!

Here's the dyno chart showing the 91 Octane pull along with a few pulls on E85 to show how consistent the power is:

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  • Great build! Is the DP catless? And did you dump EWG to atm? I’m a little concerned for that clutch haha.

    Dionysios on
  • How much will a build like this costs?

    Steve on

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