How would a set of 275/40R17 RA1s perform on 17x8 rims? Is 275 too wide for AutoX?

 

If you are serious about auto-x, meaning you want to win a title at a regional event or something you will need racing slicks like Hoosier as04a's or Kuhmo V710's. Other that any tire you have will work well enough. I am running 275/35-19 T1S on heavy-*** RH J-5 wheels. I don't plan on winning but I plan on having fun, which is what auto-x is all about.

In general though the more tire the better. We have so much power that the added traction will only help.

Have fun.

 

The Toyo RA1s are race compund, but they aren't slicks. I don't live too far from the track, but it's far enough that I don't want to drive there on a set of Hoosiers. I figure that the RA1 is a pretty good compromise.

I'm not looking to win a title, just be a little more competitive. I'm still a rookie.

 

Then again I'm thinking you'd want a stiffer sidewall for cornering feel and tire longevity. Going too wide would cause the sidewall to "rollover" in corners and cause a loss of control. Not having autox'ed before, take my advice for what it is...just personal driving & rim/tire combo experience.

 

In my current search for tires, the dealer said the RA-1 and Kumho Victo V700 are backordered in 255/40-17, which I was going to use all around or just for the front, with 275/40-17 on back.

The wheels I'm using are 17x9 w/ a 27 offset. Any idea if 275/40-17's will fit all around?

 

275 all around is fine if you think you can handle it. the car will bite a lot harder going into turns because of the wideness up front which will cause your rear to come out more. I dont know your car set up or how you drive but ive been tracking for just over a year and happy with 245 all the way around I do however want to go up a notch. PM eagle1 or Thx928 both are track gods. I learned everything from them. Eagle1 runs 275 all around RA1's thx runs hoosier slicks.

Just name sure you have enough brake power to make those things stop.

what track do you run at?

 

I have two different wheel set ups that I use for the track but it is for road racing and not auto cross.
One set up is on Nismo 18 inch diameter wheels, with 245/40 in front and 275/35 in the rear using the new Nitto NT-01 rubber. Those have very grippy compound and radical siping, very close to slicks. They brake and corner more aggressively than the Toyo RA-1, have a high modulation response (quickly snap back to shape) and strong sidewalls. They really are a fine tire, but NOT for autocross as you have to get them up to temp and that takes a warm up lap on a road racing track. But since they are just being released it could be hard to score a set. Worth the wait if you can get them, and reasonably priced between the Kumho and Yokohama offerings.

My other set is 275/35 all around on 18 inch Gram Lights (forged) with Toyo RA-1 rubber. You need to use a 3mm spacer disc on the fronts if you run that big a tire up front to keep it from rubbing.
That set up gives a lot of bite and promotes more oversteer. But again, that is a track set up, not an autocross set up.