Im going to start using RA-1's for HPDE's next year. A friend told me about buying used RA-1's from www.Bimmerworld.com. Basically, they run them for a few sessions on their race cars and then sell them for a discounted price. They have two prices depending on tread depth ($50 or $100) and someone said they got 3 weekends out of a set. They only have one size which is 235/40-17.

Im wondering if there are any issues, besides speedometer error, in running these slightly missized tires? Also, would I have any problem running these on a 9 inch wheel? My plan is to use the used tires for the first few events and eventually get a set of new 255's to run on.

$75-125 saved per tire equals that many more DE's I can pay for.

 

They should work, but 235's would be the narrowest tire I would run on a 9" wheel. Why not just run them on you stockers?

 

Well, I eventually wanted to step up to a wider tire and I dont want to drive to the events on the Toyo's. I think Im leaning more towards just getting new 255's now. They should last me quite a few events since I wont be shaving them, plus I can run them in the rain if need be.

 

I didnt shave and got a full season of autox out of my 255 RA1's, and should be able to get alteast 5 more events out of them next season. Ill probably buy another set once these are toast, i am very happy with them.

 

You can get most of a season out of a new set and from bmwwheels.com the 255/40-17 is $159. But a 235 will work with a ~3% speed error. Toyo OKs them for up to a 9.5" wheel. And they're a pound or two lighter than the 255. You'll like the RA-1, they hold their grip after many heat cycles.

Dave

 

255/40/17 fit just fine on the stock Enkei 17" x 8" wheels with no modifications. I have gone through four sets, getting an average of about 10 HPDE days on a set, running lots of track time each day. Unless you drive like Kent Jordan, don't shave them, it just reduces tread life big time.