Joe loaded the Wester's Race Tune into my 2007 GXP and I drove in home about 70 miles. I wanted to share my impressions.
In a word: Holy crap!! OK, that's two words. I found it spun up a little quicker from a dead stop to 3,000 rpms. Then, it started kicking like an army mule, as boost built to pin at 23 psi for as long as I could hang in, which was 6k+, and still far below the "new" redline. I had to end the experiment as the other big gauge next to the tach started edging into dangerous territory. There is a distinct surge of intense torque at around 4k that builds momentum very quickly. Our cars are a bit porky (no offense but true), so they hold on to that momentum very well, and speed builds quickly.
It appears that all "for your own good" nonsense has been sent home to mommy. For once the driver is in placed in touch with the wild, unrestrained potential of the forced induction direct injection system. It takes some getting used to, and all is not smooth and silky, particularly between shifts. But the sound of the turbo whining as the tach needle buries itself past the stock redline, the building G forces slam you back into your seat, and you adjust the wheel ever so slightly to stay ahead of the body twist. Well. Let's just say its well worth the investment. And despite the fact that I run the much reviled Fujitsa intake and I/C tubes, it threw no codes so far, in both WOT and quiet street driving modes. Speaking of which, out of boost, the tune is virtually the same as stock. Idle quality and low rpm operation and efficiency are unaffected.
BUT -- I have noticed that the massive midrange torque reveals the shortcomings of the chassis and suspension for predictable and solid handling. The minimal center section of the chassis and the weakness of the factory-supplied cookie sheet that passes for a cross frame brace requires one to dial in a little lefthand countersteer to compensate for the twist in the frame when the boost comes on hard at 3k on up. The left hand rear wheel gets light or spins when hitting peak torque as the side in the direction of rotation digs in.
This is OK and kind of fun in a straight line as the rear walks out and the LSD hooks again, but would not be so good rolling on throttle with the front wheels turned, hammering on to build speed out of a turn on the autox course or track, or even on the twisties on the street. Also, there was noticeable squat as the torque started kicking, and dive on hard braking. Bottom Line: I think the Race Tune calls for chassis stiffening, and a racier suspension. Strut tower brace, backbone, diff. brace, and a rear end brace at least. Coilovers with a higher spring rate would help the squat and dive.
The performance enhancement with this tune is almost unbelieveably dramatic. You will have to learn to drive your car all over. While you are doing that, you will need to be careful and show some respect, as you cute little cruiser will be far less forgiving of dumb driving mistakes than before. The cruiser becomes kind of a bruiser. Tires will surely not last as long, as you will spend considerable time at the limits of traction if you live in the power band of this tune. Can't wait to test this in a closed course, timed event. My helmet's off to you, Lyndon.
