shomesomesho
G-force addict
Made a few changes to the SHO that I think helped dramatically, leading to a top 5 finish (of 115) last Sunday's event. Results here (scroll to bottom for overall ranked raw times).
Setup changes:
- upgrading to 17x8 rims with 245-40's - this I think made the biggest difference. There is considerably more margin before reaching the traction limit. Previously was running 225-50/16's on 16x7's, which are like training wheels in comparison. Even though the 17x8 rims+tires is heavier (41 lbs. vs. 36 lbs.), the gain in traction & stability far outweighs the weight gain (no pun intended
). If someone makes 17x9 rims in the proper bolt pattern and offset, those would be even better. The hunt begins.
- smaller rear swaybar, 20mm to 18mm (rear alignment 1/8" toe-out, 2.1 deg neg camber). Car still oversteers a tad too much, especially during hard trailbraking, where I find I have to countersteer to stabilize the car. That's time lost. I can't seem to find any smaller swaybar, so I will probably set the rear toe to zero, or toe-out to 1/16". I might even try running without a rear swaybar. While oversteer is nice & fun, and it feels faster, in reality it's not. Neutral is better.
- air/fuel ratio 12.8 (previously 13.1); I did back-to-back runs comparing each setting and was about 0.8 sec faster with the 12.8 A/F ratio. That's the best evidence I have right now short of dyno data.
The SHO was the fastest FWD (and faster than all the AWD's for that matter) out there, but got beat out by a Z06 (raw horsepower & tq, no surprise there) and a stock '84 Porsche 944 (non-turbo 4-cyl 2.5L, 170hp/140 tq, 2900 lbs.). The husband & wife driving the 944 are both world-class autocrossers, having each won multiple National championships. That is both humbling and encouraging to me, especially seeing what can be accomplished with that level of driving skill given the HP limitations of that car.
I think the SHO has a little more left in her, probably about 1 to 1.5 seconds more, if I cleaned up my driving and tweaked the rear to be a little less loose. Other than that, probably the biggest limitations at this point is lack of enough torque to pull out of the turns, especially in that critical 3-5k rpm range. It just may be time to strap on the supercharger.
P.S. If you look at the 4th to 8th place finishes, amazingly the time separating them is merely tenths to sub-tenths of a second, literally less than an eye-blink. Think about it - that's time that could be made up just by shifting a little faster, letting the clutch out a little sooner, getting on the gas a little quicker, or even just by a more effective starting line launch.
Setup changes:
- upgrading to 17x8 rims with 245-40's - this I think made the biggest difference. There is considerably more margin before reaching the traction limit. Previously was running 225-50/16's on 16x7's, which are like training wheels in comparison. Even though the 17x8 rims+tires is heavier (41 lbs. vs. 36 lbs.), the gain in traction & stability far outweighs the weight gain (no pun intended
). If someone makes 17x9 rims in the proper bolt pattern and offset, those would be even better. The hunt begins.- smaller rear swaybar, 20mm to 18mm (rear alignment 1/8" toe-out, 2.1 deg neg camber). Car still oversteers a tad too much, especially during hard trailbraking, where I find I have to countersteer to stabilize the car. That's time lost. I can't seem to find any smaller swaybar, so I will probably set the rear toe to zero, or toe-out to 1/16". I might even try running without a rear swaybar. While oversteer is nice & fun, and it feels faster, in reality it's not. Neutral is better.
- air/fuel ratio 12.8 (previously 13.1); I did back-to-back runs comparing each setting and was about 0.8 sec faster with the 12.8 A/F ratio. That's the best evidence I have right now short of dyno data.
The SHO was the fastest FWD (and faster than all the AWD's for that matter) out there, but got beat out by a Z06 (raw horsepower & tq, no surprise there) and a stock '84 Porsche 944 (non-turbo 4-cyl 2.5L, 170hp/140 tq, 2900 lbs.). The husband & wife driving the 944 are both world-class autocrossers, having each won multiple National championships. That is both humbling and encouraging to me, especially seeing what can be accomplished with that level of driving skill given the HP limitations of that car.
I think the SHO has a little more left in her, probably about 1 to 1.5 seconds more, if I cleaned up my driving and tweaked the rear to be a little less loose. Other than that, probably the biggest limitations at this point is lack of enough torque to pull out of the turns, especially in that critical 3-5k rpm range. It just may be time to strap on the supercharger.
P.S. If you look at the 4th to 8th place finishes, amazingly the time separating them is merely tenths to sub-tenths of a second, literally less than an eye-blink. Think about it - that's time that could be made up just by shifting a little faster, letting the clutch out a little sooner, getting on the gas a little quicker, or even just by a more effective starting line launch.
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