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981 GT4 Clubsport (Michelin Slicks), Buttonwillow 1CW. 1:55.31. This was my first time a GT4CS, seems like an awesome car. I think I can knock another second or two off this with seat time and minor setup tweaks. Video:
Crossing another track off my bucket list. Made the trip up from Austin to Road America. We watched the indy race on Sunday at turn 5 and then had two blissful days on the track with Nord Stern PCA. Kyle Busch was there with us, practicing for the coming nascar race. Super interesting to watch his antics.
I started on Cup 2s and within a couple sessions was feeling pretty good, got down to a 32. Second day the Hoosiers came out and I was able to shave another 5 seconds off of that to a 27.5. There is easily another couple seconds to piece together from all my best attacks on each corner, and a likely many more with some coaching from someone who knows the track well. My second day was cut short with a low-coolant-error that put the car into limp mode.
Not claiming this is a best time or anything, but lots of onscreen data for folks who are about to learn the track. I wish I had this to learn before I got there.
Sean Reiche, driving my car at Pitt Race, did a 1:57.67. The tires were overinflated to reduce edge wear which slowed him down a bit.
2021 GT4 with PDK transmission. Apex Pro shows this as a 2020 718 GT4 unless manually edited.
Tires were Dunlop Race 2 at 35/36 hot, instead of my more normal 32/33.
Front camber was -2.5°. Rear was -2.0°.
Toe was close to 0 in front and 13' per side in the rear.
I have adjustable rear toe links to get enough toe at that camber. Everything else is tock.
@ShakeNBake Thats an epic time at Road America for a street GT4, 2:32 on Cup2s and 2:28 with an R-Compound are right up there with some of the best I’ve seen yet. Well done. You guys had some great weather. Dodging storms the last few days at Road America with Northwoods Shelby this weekend.
@ShakeNBake Thats an epic time at Road America for a street GT4, 2:32 on Cup2s and 2:28 with an R-Compound are right up there with some of the best I’ve seen yet. Well done. You guys had some great weather. Dodging storms the last few days at Road America with Northwoods Shelby this weekend.
How aggressive is your track tune?
We did have epic weather, high 70s and a smidgen of rain on Monday! I could not ask for a better day. Well, I did get black flagged very first session for passing to close to the kink, and then proceeded to miss the black flag - that could have gone better.
Alignment is -3.3F/-2.8R, 2mm toe in rear, 1mm toe out front, 10 degrees of caster. Using the tarret camber plates to get the caster up with that much camber, which seems to be key on this car. I don't recall the ride height exactly, but it's about 0.5" lower (maybe more) than stock, and we've messed with the rake to dial out some understeer, I think it's about +5mm from stock (rear higher relative to front).
Sean Reiche, driving my car at Pitt Race, did a 1:57.67. The tires were overinflated to reduce edge wear which slowed him down a bit.
2021 GT4 with PDK transmission. Apex Pro shows this as a 2020 718 GT4 unless manually edited.
Tires were Dunlop Race 2 at 35/36 hot, instead of my more normal 32/33.
Front camber was -2.5°. Rear was -2.0°.
Toe was close to 0 in front and 13' per side in the rear.
I have adjustable rear toe links to get enough toe at that camber. Everything else is tock.
Nice job on PittRace and remarkably similar to my time. Only been once but enjoyed it even if can be a little tricky to instruct and plan to go back again. Manual 981 GT4 on RE71s with streetable alignment yielded my time at 157.60.
Trying different lines and approaches with data helped as the track does allow you to overdrive, but trick seems to be patience is rewarded.
Last edited by Errsomeone; 07-06-2021 at 06:20 PM.
I don't know what it is worth but he had about 190# of ballast in the car, me!
rule of thumb: every 100# is worth up to 0.5 seconds per minute of lap time. Does depend a on the car/horsepower/aero/etc. So in this case, it’s would certainly be +1 second and up to ~2 seconds.
rule of thumb: every 100# is worth up to 0.5 seconds per minute of lap time. Does depend a on the car/horsepower/aero/etc. So in this case, it’s would certainly be +1 second and up to ~2 seconds.
Let's do the math. 190# would be 0.95 sec/min and the lap was 1.928 min, so 1.83 sec or 1:55.84. My personal riule-of-thumb is I'm about 5% slower than the best non-professional drivers on this track. My best lap that day was 2:01.78, which is 5.1% slower. Close enough for government work!
Rule-of-thumb. I'm about 10% slower on tracks where I don't have the level of experience I do at Pitt Race. I'm about 15% slower than a professional driver [not Lewis or Max!] Conclusion: I'm pretty slow but I have fun!!
rule of thumb: every 100# is worth up to 0.5 seconds per minute of lap time. Does depend a on the car/horsepower/aero/etc. So in this case, it’s would certainly be +1 second and up to ~2 seconds.
Going to 32As would save about 20 lbs or .1 sec. Correct?
06-07-2021, 10:01 PM
