Stick the Corners
Active Member
I got to say I’m a bit confused about changing my stock C4 Z51 1984 wheels to get increased options for tires and prices. As you know, the Z51 gave me 16 inch wheels with 8.5 width in front and 9.5 in the rear with offsets in both cases of 32mm.
At first, the often suggested ZR1 wheels at 17/ 11 inch width and 36 or is it 38mm offset would seem to keep pretty close the rear suspension geometry. Another suggestion others have made are switching to wheels of 18/9.5 with 40mm offsets which may also be okay. One advantage I see with this is that these wheels can go on the fronts also. Not sure if 17/11 ZR1s can or should go on the fronts. If not ok for the front, what is the best choice for the fronts in a 17 inch wheel?
This could be overthink, but I am beginning to understand that things are technically more complex. Concepts involving Kingpin offset , scrub radius and bearing loads all affect the suspension. These changes moreover could affect torque steer, braking effects , and pot hole absorption, as well as suspension longevity requiring increased maintenance.
Mitigating these effects by keeping the new combination of wheel and tire, possibly utilizing increased tire tread contact patch could help getting the center of the tire position close to the same as my 255/50 16 tires, if that is actually desirable both from a maintenance versus an increased performance perspective. I would like to know whether minimal spacers need to be considered in the calculation with some of these tire/wheel combinations. I have seen that larger spacer kits are available when considering replacing with newer corvette wheels. That maybe ok but are there problems with that? Would spacers even be allowed by the SCCA if I wanted to Autocross?
Also if cost is removed from the equation, should we be looking for the widest tire possible to fit in our wheel wells without encroachment or the need for structural body modifications? Drivability versus performance would seem to be at odds with each other in the fronts.
I’d be surprised if this collective knowledge base hasn’t already thrashed these concepts to minimize the trade offs that probably always need to be balanced.
At first, the often suggested ZR1 wheels at 17/ 11 inch width and 36 or is it 38mm offset would seem to keep pretty close the rear suspension geometry. Another suggestion others have made are switching to wheels of 18/9.5 with 40mm offsets which may also be okay. One advantage I see with this is that these wheels can go on the fronts also. Not sure if 17/11 ZR1s can or should go on the fronts. If not ok for the front, what is the best choice for the fronts in a 17 inch wheel?
This could be overthink, but I am beginning to understand that things are technically more complex. Concepts involving Kingpin offset , scrub radius and bearing loads all affect the suspension. These changes moreover could affect torque steer, braking effects , and pot hole absorption, as well as suspension longevity requiring increased maintenance.
Mitigating these effects by keeping the new combination of wheel and tire, possibly utilizing increased tire tread contact patch could help getting the center of the tire position close to the same as my 255/50 16 tires, if that is actually desirable both from a maintenance versus an increased performance perspective. I would like to know whether minimal spacers need to be considered in the calculation with some of these tire/wheel combinations. I have seen that larger spacer kits are available when considering replacing with newer corvette wheels. That maybe ok but are there problems with that? Would spacers even be allowed by the SCCA if I wanted to Autocross?
Also if cost is removed from the equation, should we be looking for the widest tire possible to fit in our wheel wells without encroachment or the need for structural body modifications? Drivability versus performance would seem to be at odds with each other in the fronts.
I’d be surprised if this collective knowledge base hasn’t already thrashed these concepts to minimize the trade offs that probably always need to be balanced.
