Importance of diameter for competition tires
05-04-2022, 05:09 PM
#1
Senior Member
Thread Starter
Importance of diameter for competition tires?
I'm shopping for competition tires (first time on this car, 2017 C43) and it is difficult to find a set for stock staggered 18" or 19" wheels, or even fitting on +1 inch wider wheels than stock. I'm trying to stay close to the stock diameter of 26.0 inches. Is that important? For example, this set of Toyo R888R - are they too small? Does it matter?
Front https://www.discounttiredirect.com/b...-r888r/p/40831 25.39"
Rear https://www.discounttiredirect.com/b...-r888r/p/40828 25.31"
I assume nobody goes with a square setup with, for example, 8.5" wide wheels on all 4 corners? I know the offsets would be different, but the tires would be the same.
Thanks for your input.
Front https://www.discounttiredirect.com/b...-r888r/p/40831 25.39"
Rear https://www.discounttiredirect.com/b...-r888r/p/40828 25.31"
I assume nobody goes with a square setup with, for example, 8.5" wide wheels on all 4 corners? I know the offsets would be different, but the tires would be the same.
Thanks for your input.
Last edited by GermanCarShow; 05-04-2022 at 06:32 PM.
05-04-2022, 07:09 PM
#2
square set up would be ideal, would counter balance the understeer.
within 3% is the go to for diameter. 235/45/18 would be closer but adds rotational mass and roll over - which, without proper suspension modification is a moot point I guess. K3's with stiffening braces would be at the top of my list. Even then you'll be wanting more. It's a big heavy car that wallows in turns.
within 3% is the go to for diameter. 235/45/18 would be closer but adds rotational mass and roll over - which, without proper suspension modification is a moot point I guess. K3's with stiffening braces would be at the top of my list. Even then you'll be wanting more. It's a big heavy car that wallows in turns.
05-04-2022, 08:50 PM
#3
Senior Member
Thread Starter
I had not thought of that, interesting point. Do others with significant track time want to back that up?
Within 3% difference between front and rear? Or, within 3% of stock 26.0" diameter? My example R888R's are nearly identical front and rear, but are near the 3% limit from stock of 25.22".
Well, I know it's not a 911 or Elise. And I'm no pro, so the car has better skills/limits than me. I'm just getting started. I'm thinking wheels & tires this year. Maybe brakes next year. Suspension would be after that, eventually (biggest cost). This is my daily driver that I just got last week, so the wallet is a bit light and I'm only planning a few events this year. I get more vacation days next year!!
Within 3% difference between front and rear? Or, within 3% of stock 26.0" diameter? My example R888R's are nearly identical front and rear, but are near the 3% limit from stock of 25.22".
Well, I know it's not a 911 or Elise. And I'm no pro, so the car has better skills/limits than me. I'm just getting started. I'm thinking wheels & tires this year. Maybe brakes next year. Suspension would be after that, eventually (biggest cost). This is my daily driver that I just got last week, so the wallet is a bit light and I'm only planning a few events this year. I get more vacation days next year!!
