Widest front tire for AS autox?
#16
on my 986 s, I have run the Hoosier A6 in 245/35/18 height 24.7",275/35/18 height 25.5"and 285/30/18 height 24.7 on my the 245 and 275 were on my 18x7.5 stock wheels with a 1/4" spacer. the 245 clears everything, the 275 rub's on the fender liner polishing it and the lower spring purch. the 285 were mounted on a 18x9 stock rear rim mounted on the front. it will rub the liner polishing it. I have not tried the 255's which will be my next purchase.
I did Mount a 285 on the 7.5 but did not like how they looked on the rim. Did not run them at any events.
I like a very sharp front on my cars, for this I run alot of pressure up front in the middle 40's and about 10lbs lower in the rear. A lot of others run they pressures diffrently. personal preference for most .
just my 2 cents
Rob
I did Mount a 285 on the 7.5 but did not like how they looked on the rim. Did not run them at any events.
I like a very sharp front on my cars, for this I run alot of pressure up front in the middle 40's and about 10lbs lower in the rear. A lot of others run they pressures diffrently. personal preference for most .
just my 2 cents
Rob
#17
Thread Starter
Pro
on my 986 s, I have run the Hoosier A6 in 245/35/18 height 24.7",275/35/18 height 25.5"and 285/30/18 height 24.7 on my the 245 and 275 were on my 18x7.5 stock wheels with a 1/4" spacer. the 245 clears everything, the 275 rub's on the fender liner polishing it and the lower spring purch. the 285 were mounted on a 18x9 stock rear rim mounted on the front. it will rub the liner polishing it. I have not tried the 255's which will be my next purchase.
I did Mount a 285 on the 7.5 but did not like how they looked on the rim. Did not run them at any events.
I like a very sharp front on my cars, for this I run alot of pressure up front in the middle 40's and about 10lbs lower in the rear. A lot of others run they pressures diffrently. personal preference for most .
just my 2 cents
Rob
I did Mount a 285 on the 7.5 but did not like how they looked on the rim. Did not run them at any events.
I like a very sharp front on my cars, for this I run alot of pressure up front in the middle 40's and about 10lbs lower in the rear. A lot of others run they pressures diffrently. personal preference for most .
just my 2 cents
Rob
I'm considering a 285/30/18 V710 on my 18x8 front, stock offset, camber -0.75. I would also go with a 305/30/18 V710 in the rear.
Sounds like the front will likely "polish" the fender, the strut, or both. Does "polishing" preclude running it, or is it more of an intermittent light "haze" during hard cornering only. Thanks!
#18
Somehow I missed this post.
I'm considering a 285/30/18 V710 on my 18x8 front, stock offset, camber -0.75. I would also go with a 305/30/18 V710 in the rear.
Sounds like the front will likely "polish" the fender, the strut, or both. Does "polishing" preclude running it, or is it more of an intermittent light "haze" during hard cornering only. Thanks!
I'm considering a 285/30/18 V710 on my 18x8 front, stock offset, camber -0.75. I would also go with a 305/30/18 V710 in the rear.
Sounds like the front will likely "polish" the fender, the strut, or both. Does "polishing" preclude running it, or is it more of an intermittent light "haze" during hard cornering only. Thanks!
18x9 +50 (7" backspace), 18x12 +69 (9.25" backspace).
So I got 265/35/r18 kumho v700 on front rims and it barely fits, it actually fits only because I have GT3 LCAs and -2.4 degree camber points top of the tire inside into wheel well. no way 285 tire can fit there. that is on 9" rim with 50mm offset on a 997 car.
and that`s on those custom wheel - 285mm tires on a stock 8" rim with 57mm offset (even if you will manage somehow to mount that 285mm tire on a 8" rim) will rub at fenders.
IMHO max tire that will work on stock 8" and 10" rims are 245/305 and 305 is somewhat too wide for rear 10" wheel. but you can get toyo ra1 in those sizes and they are of correct diameters so it will work better imho than odd 285/305 combo. to put 285 in front you really mush roll up your fenders and put 9.5" rims in front. I think ccw makes such as well.
#19
Well, I guess you can teach an old dog new tricks. My co-driver feels the car understeers too much on corner entry (I think its liveable) and we have done all the legal adjusting we can think of to reduce it.
PedalFaster's comments made me realize the one thing we have not done is go wider than 255s in the front. So, I am doing a $600 experiment by buying a pair of 275s for the front. We should be able to do back to back comparisons. I'll let you know about fit and performance in a few weeks.
PedalFaster's comments made me realize the one thing we have not done is go wider than 255s in the front. So, I am doing a $600 experiment by buying a pair of 275s for the front. We should be able to do back to back comparisons. I'll let you know about fit and performance in a few weeks.
#20
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Rennlist Member
Rennlist Member
I don't think you'll ever get a 285 V710 to mount on an 8" rim. 245/35 V710's are a royal PITA on an 8" rim, I can't see how you'd ever get the V710 on there. The Hoosiers mount a lot easier for some reason. Many times have I picked up a partially mounted 245/35 V710 on an 8" rim from a tire shop and had to finish the mounting myself with lots of tire snot, guys jumping up and down on the rim, heat, and air pressure.
FWIW, there was a thread quite a while back from the GT3 guys running in SS (Peter Lier if I recall correctly). They found in back to back testing that the 285 on the rear was faster than wider sizes due to the better gearing. Your very tall 2nd gear is probably one of the biggest liabilities of the car (assuming it is similar to the 993), and a wider/taller rear tire only exacerbates this problem.
FWIW, there was a thread quite a while back from the GT3 guys running in SS (Peter Lier if I recall correctly). They found in back to back testing that the 285 on the rear was faster than wider sizes due to the better gearing. Your very tall 2nd gear is probably one of the biggest liabilities of the car (assuming it is similar to the 993), and a wider/taller rear tire only exacerbates this problem.
#21
It's pretty common, actually; I personally ran an RX-8 with 285 V710s on the stock 18" x 8" wheels for a year. You just need a good tire guy, preferably one who's used to dealing with Stock class autocrossers and our ridiculous demands.
#22
Bringing this thread back to life for another datapoint.
This year I moved from 275/35/18 fronts on my 987 to 285/30/18 fronts on stock size and offset 18x8 rims and identical 285/30/18 rears on stock size and offset rims 18x9. They all fit without spacers! These are Hoosier A6s no info on Kumhos.
I like the way these tires work and wear better than the 275s.
This year I moved from 275/35/18 fronts on my 987 to 285/30/18 fronts on stock size and offset 18x8 rims and identical 285/30/18 rears on stock size and offset rims 18x9. They all fit without spacers! These are Hoosier A6s no info on Kumhos.
I like the way these tires work and wear better than the 275s.