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Racerflash
11-19-2012, 11:25 AM
Hey guys, I'm looking for some Autocross tires to mount on stock 17x7s. The Hoosier A6 205/40s are so pricey, but Kumho has R-Compounds about $50 per tire less, but only in a 215/40r17. Does anyone know if the extra 10mm width causes any problem with stock springs (not lowered)?

Thanks
Flash

Racerflash
11-19-2012, 03:29 PM
Not worried about the tire fitting on the rim, but the clearance of the tire in the wheel well and around suspension, etc.

Thanks for any feedback you can offer.

BigDaddySRT
11-19-2012, 04:22 PM
Not worried about the tire fitting on the rim, but the clearance of the tire in the wheel well and around suspension, etc.

Thanks for any feedback you can offer.

Your tire shop will be "upset" when they are trying to shoe horn a tire on a Rim Width not recommended by the manufacture.

Pinecone
11-19-2012, 04:37 PM
10mm wider should be fine. But for autocross especially, you don't want any taller (diameter) tire. Reduces the effective gearing, reducing acceleration.

OK, looking at Tire Rack (Rim wide, section width, diameter)

Stock tires 205/40-17 5.5 - 7.5 8.1" 23.7"
Kumho V710 215/40-17 7 - 8.5 9.1" 24.1"
Hoosier R6 215/40-17 7 - 8 8.8" 23.8"
Hoosier A6 225/40-17 7 - 8 9.8" 23.8"

I don't see a Hoosier A6 (autocross tire) in 215/40, smaller is 225/40. The R6 is theroad race tire and is too hard and needs too much heat to work well for autocross.

The A6 225/40 is 1.7" wider than the stock wheel, so an extra 0.85" (a bit over 3/4") to the each the outside and inside. Might be a problem.

Section width is the actual width of the tire as installed.

Stock 17" wheels are 7" wide, so all these tires will fit the wheel.

Racerflash
11-19-2012, 04:47 PM
Your tire shop will be "upset" when they are trying to shoe horn a tire on a Rim Width not recommended by the manufacture.

Thanks, but what I meant about not worried about wheel figment is that I already checked Tire Rack specs and they recommend 7-8.5" rims for this tire. So I'm OK with the min width.

Racerflash
11-19-2012, 04:48 PM
Thanks, I'll check the diameter for sure too!

Crazy Otto
11-19-2012, 08:20 PM
Unless you are hell bent on setting FTD in your class of something like that you should consider toyo r888 - you can drive to the track on these. Granted you will not have ultimate grip as an A6 but that may be ok. In fact, the A6 may be too much for this car with its stock suspension. Plus you can enjoy the r888 somewhat on the street when its warm.

Another option is a extreme performance street tire like ghe yokohama ad08 or dunlop direzza star specs which are on sale right now by tire rack. These street compounds rival the performance of yesteryear s dot r compounds.

My personal experience with the khume v710s were ok. Consider this inbetween a hoosier r6 and a6 in terms of warmup time. I sjffered the groove of death on these as others have.

I would recommend you call tire rack and discuss the yoke ad08. This may be a splendid compromise. I cant wait to get my set nsxt spring.

Crazy Otto
11-19-2012, 08:22 PM
Were you trailering your car to autocross?

Racerflash
11-20-2012, 12:37 AM
Were you trailering your car to autocross?

Not trailering but less than 5 miles so in the past I've switched tires at home and driven. When rain looked possible, my son would bring the tires, jack, etc to the event in his pick-up and we would switch tires there. He also co-drives my car (and beats me now and then!). I've driven home before in the rain with some slick Kumhos and it's not fun!

Thanks to all for the advice,
Flash

jguerdat
11-20-2012, 07:55 AM
It's my understanding that the GS Abarth at Nationals this year was on Hoosiers so fitment shouldn't be a problem.

I'm sticking with street tire classes. 215/40-17 will be fine although the Hoosiers are obviously wider...