For this project in the months ahead we are going to improve upon the STi's strong point, mainly its torquey and tractable engine, making it much faster while keeping its streetable and road raceable characteristics. Mostly we'll be paying a lot of attention to improving the cars weak points, the handling and braking. Project STi's goals will be to keep its easy street persona while being able to rip the 11/44-mile in the 11s and also win a Time Attack.
We are going to do extensive suspension work to improve every aspect from the geometry to the damping. Our brake work will bring out the full potential of the Brembos and we will work to exploit every possibility for easy bolt-on power.
We started with a used 2004 STi bought from a private party. Although the car was in mint condition and essentially stock, it was equipped with some sort of horrible aftermarket lowering springs that lowered the car too much and were too soft. This led to bottoming out the front suspension under cornering loads and horrible understeer. Unfortunately, this is typical of aftermarket lowering springs. A car as good as the STi is in stock form it is easy for the typical aftermarket tuner to mess it up. We were unable to even come close to approaching the lap times of a stock STi at Streets of Willow Raceway. These springs will hit the garbage soon enough and we will replace them with adjustable dampers equipped with coil-overs.
The previous owner had curbed the stock wheels hard and probably ran the car through a carwash with unprotected rails scarring the wheels badly. This looked ugly. Mackin Industries saved the day and provide us with some ultralight forged bronze Volk CE28N wheels in 18x8.5 with a 44mm offset. The CE28N is a high tech, superlight forged wheel favored by touring car racers around the world. Each wheel weighs a feathery 18 lbs. Impressive for an 18-inch, wheel.
Our racing experience also tells us that the CE28N is an exceptionally strong wheel as I have personally banged many a set hard against FIA curbs and potholes on the track with no damage! We also needed some sticky tires in anticipation of our planned suspension mods and excess of power. We selected a set of 245/40-18 BFG G-Force KDW tires for all around wet and dry street performance. At a later date we will probably get a set of 17-inch wheels with some sticky R-compound tires just for track use.
As a first step we drained all of the fluids from the transmission, transaxle, differential, and engine and replaced them with synthetics from Motul. We will get more into these lubes at a later date. Next, we baselined Project STi on XS Engineering's 4WD dyno and were surprised with the results. Project STi spit out an impressive 246.3 hp and 241.8 lb-ft of torque.
In our next installments, we will try to see what some basic bolt-ons do to Project STi's power, start to tidy up Project STi's handling, and turn XS's Eric Hsu loose on tweaking the STi's factory ECU.
Finally, we plan to have a showdown, a war to settle the score. Project STi vs. Project EVO head-to-head. Who will win? Stay tuned.