Originally Posted by FiKtIOn
Wow. Considering how crappy 712's are (and how grippy MX's are), I think there's something else going on to make you that much slower.
Given, oversizing might be screwing up your steering feel and possibly your turn in, but there's no way it's making you that much slower by going to a tire which is much stickier.
Yep, it doesnt make sense.
The only thing I can think of is that the tread depth on the newer tires is allowing the car to wallow more than the worn-down 712's they replaced. I can testify that the car was very loose the first day on the track. Tire pressure adjustments did little to correct the problem, and I did find that the MX's like to have ~5lbs more air than the 712s to work well. I even spun the car off the track for the first time in 3 years on my new grippier MX's. Damn "South Bend"!
It is not due to changes in the car setup, or power loss. I really dont think my driving ability has deteriorated so much since installing the MX's, that installing a Cobb Stage 1 power package cant compensate. The car pulls like a motherf*<}#r now, so I know the engine isnt to blame. I still feel like these tires allow more body roll. I recommend wider rims.