When I first got my STI I knew I wanted to do track days. So I started looking into it and I ended up at Wine Country Motorsports at the Sears Point (Infineon) Raceway in Sonoma. Paul was very helpful there and I purchased two 4 point harnesses for my STI and he recommended that I go up the hill to WORKS to get them installed. WORKS is a shop that primarily works on EVO's but they do some work on STI's and other cars, he told me.

So I drove up the hill and was very impressed with the staff at WORKS, they showed me around, talked with me and generally made me feel like a welcome guest. As time has gone by I've spent weekends there helping out around the shop, learning a little bit more about cars in general and my STI in particular from the Mechanics and engineers. In the last few months, the owner of WORKS, Pete Kang, has had me start to assist him in tuning cars on their Dynapack 4WD dyno. Many of you know I'm an Engineer by profession and I love solving problems, so I dove into tuning with a cheerful grin. Pete has shown me what the ideals are and what things to tweak to have differing effects. He's also very adamant about being cautious during tuning as it's not our property.

This weekend we were finally able to get my STI onto the dyno. My STI is completely stock under the hood, but Pete was adamant about the fact that the car could perform better even without any upgrades.

Once we got it on the dyno, we ran six pulls to establish a firm baseline for where the car was with the stock ECU settings. That baseline was 236.6 whp and 229.9 lb-ft of torque. The stock turbo was making 15.1 PSI of boost at 4800 RPM.

The first step was to adjust the boost to bring the boost on faster, but not too fast. I didn't want full boost before 3500 RPM as that might make the car a bit more jumpy on a corner exit than I really want. I had spoken with my Subaru Mechanic and I wanted to keep the boost under 19 PSI as well. With all that in mind, Pete and I went to work adjusting the wastegate duty cycles and boost targets. What we ended up with is this:


Honestly the boost tapered more than I wanted as the RPM's went higher, but we didn't have a lot of choice, at the higher RPM's the stock turbo with a TMIC just can't pull in more air than it is. With the changes to the boost, we moved on to the Air Fuel Ratio. We cleaned it up and leaned it out to 11.5:1 which is the ideal for a forced induction engine.

The final step was to add in timing during the power phase of the engine to give us the final results. We added in a degree or two of timing at a time, being careful to check for any knocking. Once we got it to knock slightly, we backed off the timing several degrees and cleaned up our maps and we were done. A note about the graphs, the "flywheel horsepower" heading is actually whp. Here are the final results the red line is the final run and the blue is the baseline:


Here is the power vs total torque graph:


The final numbers were 260.5 whp@5489 RPM and 274.8 lb-ft@3959 RPM.

I would highly recommend WORKS as a tuner to any STI or WRX owner, they're conscientious, kind, diligent and respectful of their customer's property. WORKS will tune your car until the tune is complete, if that takes 25 or even 50 pulls on the dyno. They don't do 6 pulls and you're done, by final count my STI did 27 pulls on the dyno, of which the first 6 were merely to establish a baseline. WORKS is also more than happy to tune to the specifications of the individual driver. An aftermarket ECU is not required, nor is a COBB AP, though both of those things can be worked with.

If you're interested in WORKS, you can find them on the web at www.worksevo.com or at Infineon Raceway.

 

Nice review.

 

Thats awesome you were able to pull 20 odd hp nd 50ft lbs with just tuning the stock motor. Thats always nice.

 

Believe me it's amazing to drive, it's MUCH faster on the accelerator now. There's very little "lag" time even at lower (read 3000ish) RPM. It was worth every penny I spent on the tune.

 

Nice! When I was reading around at norcalevo forums, these guys are one of the favorites, especially from the Evo X guys.