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Subaru STI - Now We Get The Power - Install

Project Track Star STI Stage Two: Engine Mods

Elliot Moran
Dec 1, 2007
Photographer: The Super Street Archives
130_0712_01_z+project_sti+at_the_track Photo 1/5   |   Subaru STI - Now We Get The Power - Install

(Disclaimer: Read this first sentence in your best Scarface accent-and loudly.)

Tony Montana once said, "In this country, you gotta make the money first. Then when you get the money, you get the power. Then, when you get the power, then you get the women." While this might be true for pharmaceutical salesmen and CEOs, it better not be the case for the rest of us "normal" people; otherwise, we'd end up dateless losers like Justin (a.k.a. Dirty), the new slave at Project Car magazine. When it comes to our Super Lap Battle series you don't need to make the money before you make the power. With our Project Track Star STI, we wanted to build it up for our Street class but maintain everyday drivability, which made throwing a huge turbo on and making 800 hp impractical. With Southern California traffic being an exercise in not revving your car past the 3K mark, a big turbo upgrade would not only be wasted on the street but on the track as well. Power without traction just leads to having an uncontrollable car; in turn, making you slow on the track.

130_0712_05_z+project_sti+world_sport_exhaust Photo 2/5   |   Subaru STI - Now We Get The Power - Install

To start things off we contacted A'PEXi to get some bolt-on parts. The STI comes stock with a healthy 300 hp, which is more than enough horsepower for the street, but since we were going to take it to the track we wanted to get a little more out of the car. The beauty of the STI is that getting more horsepower really isn't that difficult and can be done with simple bolt-ons. First up was to change out the exhaust. Since we're getting older by the minute, we wanted an exhaust that sounded good but wasn't too loud. We went with the World Sport exhaust, which has 65 mm piping and a stainless steel muffler. After the exhaust was installed, we fired the car up and right off the bat noticed how quiet this exhaust is. It was barely louder than stock, but with the stainless steel muffler it looked a hundred times better. After staring at the rear end of the STI for a good 15 minutes admiring our shiny new exhaust, we bolted the car on their dyno to see what kind of improvements we were looking at. When the dyno rollers stopped spinning, we were impressed to find we put an extra 10 hp to the wheels. For an exhaust that was barely louder than stock to give us this kind of power gain, we were stoked. What's even better: For those guys out there who don't mind an exhaust that's a little bit louder, A'PEXi offers their GT Spec exhaust with piping that goes up to 85 mm, which will give you even more horsepower gains.

To compliment the exhaust we'll also put on an A'PEXi Aluminum Induction Box and intake, AVC-R boost controller and Auto Timer. The Induction Box is designed to cover the filter, thus keeping the intake temperatures down by shielding it from engine heat. With the AVC-R we'll not only be able to raise the boost levels, but also control boost based on RPM. To help prolong the life of our turbo, the Auto Timer will let us cool the car down with out having to sit in it with the keys in the ignition. The next step for our STI will be to run at the Super Lap Battle Finals. We've done enough writing about the car; now it'll be time to see what it can really do on the track.

We Can Do It!As you can see we've added some bolt-on performance parts to take better advantage of our TEIN/Carbing suspension and Gram Lights/Yokohama wheels and tires. With our setup we won't be winning any dyno challenges, but that's not what we were going for. In fact, if you look at the top ranking teams at the Super Lap Battle finals and you'll see most of the cars make around 400-500 hp. Setting up a car for the street is very similar to a road course setup, on the street for a turbo car you'll want quick spooling turbo with some good midrange power. While on a road course you might hit 100+ mph on some of the straights, the majority of the time is spent in lower gears coming in and out of turns. To be fast, you'll want your car to spool quickly to help accelerate out of the turn. However, on the street, how often are you going to go 100+ mph? You'd much rather have a setup that lets you get to the next stoplight much quicker instead of just getting into full boost as you roll up to the crosswalk.


Orange, CA 92868
By Elliot Moran
1 Articles



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