Terry, autocross doesn't have the same air and rotational drag concerns of high speed track use, you know that
My lap times dropped ~10 seconds, but my point was that rolling drag & aero drag will eventually cause issues. I changed the entire suspension setup and went from -1 degree of camber up front to -3 and changed to better dampers, etc etc. Lots of other factors there
Counter Space Garage tested sticky 225s vs sticky 245s and for lower power levels on a high average speed track 225s were faster. I'm not privy to *how* they tested, but that's the info they presented.
FWIW Shenandoah circuit isn't a high speed track, somewhere like VIR I'd likely have been setting the same lap times on sticky 225s versus sticky 245s just due to drag. If I'm giving up 1 mph apex speed with narrower tires but making speed up the entire back straight then the math likely works out to a wash eventually.
Also, I think the other comments here about just slapping wider tires on with doing no other setup work is likely why the ZL1 on OP's post went slower. Balance change, everything too soft, etc etc. The ZL1 has enough power to not care much about that extra bit of rubber width causing drag. It's not a 200hp 4 banger, haha.
My lap times dropped ~10 seconds, but my point was that rolling drag & aero drag will eventually cause issues. I changed the entire suspension setup and went from -1 degree of camber up front to -3 and changed to better dampers, etc etc. Lots of other factors there
Counter Space Garage tested sticky 225s vs sticky 245s and for lower power levels on a high average speed track 225s were faster. I'm not privy to *how* they tested, but that's the info they presented.
FWIW Shenandoah circuit isn't a high speed track, somewhere like VIR I'd likely have been setting the same lap times on sticky 225s versus sticky 245s just due to drag. If I'm giving up 1 mph apex speed with narrower tires but making speed up the entire back straight then the math likely works out to a wash eventually.
Also, I think the other comments here about just slapping wider tires on with doing no other setup work is likely why the ZL1 on OP's post went slower. Balance change, everything too soft, etc etc. The ZL1 has enough power to not care much about that extra bit of rubber width causing drag. It's not a 200hp 4 banger, haha.