R Tires for Autocross - Help in Sizing
09-14-2009, 02:41 AM
#1
Addict
Rennlist Member
Rennlist Member
Thread Starter
R Tires for Autocross - Help in Sizing
I have a 1973 911 with an unmodified narrow body (no flares, fenders not rolled etc).
I have a set of 6x15 cookie cutters and 6x16 fuchs wheels. [I have run 205/60 and 205/55-15's on the street and they fit fine with no rubbing or other issues.
For one these wheels I want to put a set of R compound tires for Autocross. Looking at the Hoosier site for A6's, I see I can get:
205/50-15 which will fit and be ok; or
225/50-16 which I am unsure will fit.
(Hoosier also shows a 205/45-16 which would be better for me. Unfortunately they indicate that these need to be fitted to a 6 1/2 to 7 1/2 inch wheel.)
I would prefer the A6's to be on my 16" wheels but I am not sure they fit in my wheel wells. Will they fit or must I go with the 15" tires?
I have a set of 6x15 cookie cutters and 6x16 fuchs wheels. [I have run 205/60 and 205/55-15's on the street and they fit fine with no rubbing or other issues.
For one these wheels I want to put a set of R compound tires for Autocross. Looking at the Hoosier site for A6's, I see I can get:
205/50-15 which will fit and be ok; or
225/50-16 which I am unsure will fit.
(Hoosier also shows a 205/45-16 which would be better for me. Unfortunately they indicate that these need to be fitted to a 6 1/2 to 7 1/2 inch wheel.)
I would prefer the A6's to be on my 16" wheels but I am not sure they fit in my wheel wells. Will they fit or must I go with the 15" tires?
09-15-2009, 01:35 PM
#4
I agree with the above comments.
If you must have Hoosiers, stick with the 205 since the Hoosiers have square shoulders and a cantilever-slick look to them which can make them more difficult to fit in some applications. I occasionally run run 225/45/15 tires on 8" rims on my narrow body and they are tight. I could squeeze a 225/50/16 but I have trimmed spring plate bolts, no oil cooler lines, and heavily rolled fenders.
If you must have Hoosiers, stick with the 205 since the Hoosiers have square shoulders and a cantilever-slick look to them which can make them more difficult to fit in some applications. I occasionally run run 225/45/15 tires on 8" rims on my narrow body and they are tight. I could squeeze a 225/50/16 but I have trimmed spring plate bolts, no oil cooler lines, and heavily rolled fenders.
09-15-2009, 02:37 PM
#5
Racer
I agree with the above comments.
If you must have Hoosiers, stick with the 205 since the Hoosiers have square shoulders and a cantilever-slick look to them which can make them more difficult to fit in some applications. I occasionally run run 225/45/15 tires on 8" rims on my narrow body and they are tight. I could squeeze a 225/50/16 but I have trimmed spring plate bolts, no oil cooler lines, and heavily rolled fenders.
If you must have Hoosiers, stick with the 205 since the Hoosiers have square shoulders and a cantilever-slick look to them which can make them more difficult to fit in some applications. I occasionally run run 225/45/15 tires on 8" rims on my narrow body and they are tight. I could squeeze a 225/50/16 but I have trimmed spring plate bolts, no oil cooler lines, and heavily rolled fenders.
Kevin
09-15-2009, 05:37 PM
#6
Well, every car is a little bit different. I'd say to go on Tire Rack and check dimensions of the 205 vs. 225 and then measure the inside and outside clearance on YOUR car. I'd say they will fit with rolled fenders but I can't say for sure since I am running custom offset Revolution wheels and I'm not sure how the offset compares with the 23mm ET (I think) on your wheels.
Make sure you check for clearance on the oil lines on the '72 as they are different than other years and mine that has no external oil cooler.
Good luck!
Make sure you check for clearance on the oil lines on the '72 as they are different than other years and mine that has no external oil cooler.
Good luck!
09-15-2009, 05:52 PM
#7
Racer
Join Date: Dec 2008
Location: Lancaster, PA
Posts: 287
Likes: 0
Received 0 Likes
on
0 Posts
I used to have a car with 15x6 wheels and I have run plenty of Hoosier A6s on them.
A 205/15 Hoosier A6 will fit a 15x6 rim no problem. Any tire monkey should be able to mount them.
A 225/15 Hoosier A6 will fit a 15x6 rim but it is a stretch. An experienced tire monkey with good equipment will not have too many problems but will probably curse you under his breadth.
A 275/15 Hoosier A6 will fit a 15x6 rim but it is a huge stretch. Only a great tire monkey with a great machine will be able to mount these expect him to curse you out loud before he's done.
I do not know how these tires will fit your 911 but they will all fit the rims. I cannot speak to the 16" sizes.
My suggestion is 205 front and 225 rear.
Regards,
Alan
A 205/15 Hoosier A6 will fit a 15x6 rim no problem. Any tire monkey should be able to mount them.
A 225/15 Hoosier A6 will fit a 15x6 rim but it is a stretch. An experienced tire monkey with good equipment will not have too many problems but will probably curse you under his breadth.
A 275/15 Hoosier A6 will fit a 15x6 rim but it is a huge stretch. Only a great tire monkey with a great machine will be able to mount these expect him to curse you out loud before he's done.
I do not know how these tires will fit your 911 but they will all fit the rims. I cannot speak to the 16" sizes.
My suggestion is 205 front and 225 rear.
Regards,
Alan
Trending Topics
09-15-2009, 06:03 PM
#8
Racer
Join Date: Dec 2008
Location: Lancaster, PA
Posts: 287
Likes: 0
Received 0 Likes
on
0 Posts
09-15-2009, 06:31 PM
#9
In the context of SCCA National competition where events are won by hundredths and sometimes thousandths of a second, the marginal edge of the A6 is important. For most PCA events where competition is not as fierce, there are other factors such as car prep and driver skill that are much bigger than what the "better" Hoosier can overcome. Add to that the short life span of the Hoosier and the higher price and the Kumhos begin to look even better.
Of course, HarryD will ultimately decide which way to go. The good news is that there are no bad choices in this case.
09-15-2009, 06:48 PM
#10
Intermediate
Join Date: Aug 2009
Location: ATL, GA
Posts: 49
Likes: 0
Received 0 Likes
on
0 Posts
VNTGSPD's Avatar
Join Date: Jun 2004
Location: SoCal
Posts: 527
Default
Quote:
Originally Posted by 00r101 View Post
Look at SCCA Nationals results. Almost no drivers in Super Stock or A Stock (where 911s and Boxsters live) ran Kumhos. If you want to have the fastest tires buy Hoosier.
Agreed, but the original poster does not appear to be running Nationals in a car prepared to those rules. Judging by the comment about the stock narrow body, 6" cookies, and the sig indicating his "just for fun" Targa, I'd say that the Kumhos are a good alternative.
In the context of SCCA National competition where events are won by hundredths and sometimes thousandths of a second, the marginal edge of the A6 is important. For most PCA events where competition is not as fierce, there are other factors such as car prep and driver skill that are much bigger than what the "better" Hoosier can overcome. Add to that the short life span of the Hoosier and the higher price and the Kumhos begin to look even better.
Of course, HarryD will ultimately decide which way to go. The good news is that there are no bad choices in this case.
Join Date: Jun 2004
Location: SoCal
Posts: 527
Default
Quote:
Originally Posted by 00r101 View Post
Look at SCCA Nationals results. Almost no drivers in Super Stock or A Stock (where 911s and Boxsters live) ran Kumhos. If you want to have the fastest tires buy Hoosier.
Agreed, but the original poster does not appear to be running Nationals in a car prepared to those rules. Judging by the comment about the stock narrow body, 6" cookies, and the sig indicating his "just for fun" Targa, I'd say that the Kumhos are a good alternative.
In the context of SCCA National competition where events are won by hundredths and sometimes thousandths of a second, the marginal edge of the A6 is important. For most PCA events where competition is not as fierce, there are other factors such as car prep and driver skill that are much bigger than what the "better" Hoosier can overcome. Add to that the short life span of the Hoosier and the higher price and the Kumhos begin to look even better.
Of course, HarryD will ultimately decide which way to go. The good news is that there are no bad choices in this case.
09-15-2009, 08:19 PM
#11
Racer
Oh yeah, I ran the 225/45/15's on 6" Fuchs with no problem. Even 225/50/15's BFG R1's back in the day with no problem what so ever. I just may TRY the 225/45/15 Hoosiers on the Cookies and see what happens
Kevin
Kevin
09-16-2009, 10:12 AM
#12
Racer
Join Date: Dec 2008
Location: Lancaster, PA
Posts: 287
Likes: 0
Received 0 Likes
on
0 Posts
Agreed, but the original poster does not appear to be running Nationals in a car prepared to those rules. Judging by the comment about the stock narrow body, 6" cookies, and the sig indicating his "just for fun" Targa, I'd say that the Kumhos are a good alternative.
In the context of SCCA National competition where events are won by hundredths and sometimes thousandths of a second, the marginal edge of the A6 is important. For most PCA events where competition is not as fierce, there are other factors such as car prep and driver skill that are much bigger than what the "better" Hoosier can overcome. Add to that the short life span of the Hoosier and the higher price and the Kumhos begin to look even better.
Of course, HarryD will ultimately decide which way to go. The good news is that there are no bad choices in this case.
In the context of SCCA National competition where events are won by hundredths and sometimes thousandths of a second, the marginal edge of the A6 is important. For most PCA events where competition is not as fierce, there are other factors such as car prep and driver skill that are much bigger than what the "better" Hoosier can overcome. Add to that the short life span of the Hoosier and the higher price and the Kumhos begin to look even better.
Of course, HarryD will ultimately decide which way to go. The good news is that there are no bad choices in this case.
It's all good, OP, whatever you decide.
09-16-2009, 03:02 PM
#13
Burning Brakes
Kumho doesn't pay contingency money (i.e. tires for wins), and Hoosier does. This is one reason why the Hoosiers are more popular at nationals, but the A6 is a faster tire hands down over the V710. The A6 lasts longer than older Hoosier autocross tires (A3S04, A3S05, etc), but the V710s will give you 100-140 runs in most cases.
09-19-2009, 03:20 AM
#14
Addict
Rennlist Member
Rennlist Member
Thread Starter
Thanks for the thoughts. What I am seeing is use the 15's for my track wheels. As several noted, I am not competing for SCCA NAtionals but i do like to have "fun". I am thinking about looking for used R tires so why not the "best".
09-21-2009, 11:07 AM
#15
But again, no real bad choices here. I put some mildly used A6s on for a DE last weekend and was impressed with how well they worked. They started fading after about 5 laps but I expected that being an A6 vs R6.
Have fun!