Aftemarket wheels and tires for roadracing

[pwpanas]

Originally Posted by Bolarbag

...So I'm currently speccing my wheel sizes and offsets to suit my Brembo BBK's front and rear, you recommend 10 at the front and 11.5rear on a stock body?

Yes. Be sure to check the rim diameter you need to clear the brakes. Next, check the sizes of the tires that you plan to purchase and use. You may not be able to get near-optimal 275s or 285s in the front, and 315s in the rear. Maybe you'll end up with 265s up front, and 295s or 305s in the rear instead. Also have one or two back-up tire brands/models in case the company stops producing your first choice. Lastly, get the rim widths to match the rubber you'll be running. When you come close to your decision, please feel free to post here, and we'll provide feedback.

Originally Posted by Bolarbag

...Wont the wider tyres in the front give me a less responsive turn in - you have to bare in mind that the tracks in the UK are like 100th of the size of the ones in the U.S - i.e my local track I should get round in 58secs, there are a few bigger ones but not longer than 3mins e.t.c however I do intend to go to the Nurburgring this autumn

Low profile, wide front tires will give you a MUCH more responsive turn-in. You'll be shocked when you switch from oem 235s to 275s or so up front. Of course, it'll be a bit harder on your power steering, so be sure to follow proper maintenance, and use good fluid (eg Redline Power Steering Fluid).

Hypothetically, if you widened the back tires, and kept the oem front tires the same width, it'd push in the corners (i.e. turn-in would be less responsive). That's why you have to upgrade both the front and the back widths simultaneously and proportionally.

Please post any follow-up questions you have...and good luck with it - please keep us informed!