When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I would consider RE-71R in available sizes, 225/40-18 and 275/35-18 or, possibly, 235/40-18 and 275/35-18 or 235 front and 285/30-18 rear.
Chao, I'm curious why do you feel that 275 is a stretch on an 11" wheel? Did they not look/feel right? Bridgestone shows section width of 10.9 and acceptable wheel of 9-11". While I take it with a grain of salt, I generally like to have section width about equal to the wheel width. I currently run 275 Hoosiers on 10" rims, but most fast competitors went to 11s. Hoosier's numbers are often not what they seem, but that tire has 10,8 section width and it seems to be slightly faster on 11" rim.
11" rears are wide for 993WB but should be OK. 285 will be stretched. 295s are fine. I rebuilt my E88s down to 11" from 12"s but probably could have gotten away with 11.5s. Had too much push on 315 rears I was running before.
Plenty of threads on this in the turbo subforum.
Another data point: I run 275/35/18 on 11" 996 Turbo rims on my C4S for years and really like the overall balance, particularly on the racetrack.
Chao, I'm curious why do you feel that 275 is a stretch on an 11" wheel? Did they not look/feel right? Bridgestone shows section width of 10.9 and acceptable wheel of 9-11". While I take it with a grain of salt, I generally like to have section width about equal to the wheel width. I currently run 275 Hoosiers on 10" rims, but most fast competitors went to 11s. Hoosier's numbers are often not what they seem, but that tire has 10,8 section width and it seems to be slightly faster on 11" rim.
Many of our tires are designed with sidewalls to sit farther out than the rim. How far out looks to you is a personal choice. Thinking is to protect the rim and sacrifice tire first I guess.
I am happy to take a photo of my 11s with 295s. It is about as stretched as I want those tires to look and be.
Many of our tires are designed with sidewalls to sit farther out than the rim. How far out looks to you is a personal choice. Thinking is to protect the rim and sacrifice tire first I guess.
I am happy to take a photo of my 11s with 295s. It is about as stretched as I want those tires to look and be.
Chao, thanks! We see a lot of different tire/wheel combos at autocross, so I've seen a few combos going both ways.
On my own 993 cab I run 265s on 10" rims and, visually and feel-wise they are fine to me. I think part of it is the tire itself, some have "rim protection" extra rubber added above the bead, some don't. And the rim... I remember running RH "Speedline" rims and being amazed how far the outer rim half stuck out and how unpleasant it was to park near any curb. That was the only visually unpleasant part of those great wheels to me.
In this case I'm referring more towards what feels and communicates best at speed. i think both 275 and 285 should be OK on an 11" rim. I'd be much more concerned with the size gap between front and rear, both the width and the tire height.
Here is what I just measured on my E88 12 inch rim in my basement. Total is 12.75inches outer edge to outer edge or 32.385CM. That is why I rebuilt my rim down to 11 inches when deciding to run 295s down from 315s.
275 is 10.826 inches.
285 is 11.22 inches
Chao, I'm not sure if you are aware of the stuff below, but it's a bit more complicated than that. If you already know, sorry for all the details:
The numbers on the sidewalls, like 275, are the tread width. There is also a mounting width and section width. Most manufacturers publish them, but even those numbers are not quite consistent.
- The tread width varies from tire to tire, depending on what the manufacturer feels like regarding where "usable tread" ends on the shoulder of a particular model of tire. Depends on the shoulder form, among other things. Plus they lie on consistent basis especially when it comes to competition DOT rubber (R-comps).
- The section width is "a tire's section width (also called "cross section width") is the measurement of the tire's width from its inner sidewall to its outer sidewall (excluding any protective ribs, decorations or raised letters) at the widest point. This measurement is made without any load placed upon the tire and after the tire has been properly mounted on its industry assigned measuring rim" (direct quote from TireRack). So, we got, essentially, the measurement that would kind of tell us how wheel is protected, except we need to add another 1 depth of a sidewall, consider whether protective rib is there, see if we are using the same wheel as manufacturer for measuring, see if we are inflating to the same pressure, etc.
- There's mounting width, which is what's important for speed, especially on the track. Lately, manufacturers don't really show mounting width. The rule of thumb used to be that it's about equal to the tread width, but... The idea is for the sidewall to be fairly straight, so the choice of wheel width is actually directly related to this mounting width and should be about the same.
Another data point: I run 275/35/18 on 11" 996 Turbo rims on my C4S for years and really like the overall balance, particularly on the racetrack.
Me too. My track setup is RE-71R 235/40/18 front, 275/35/17 rear on 996TT wheels on my 993 C4S. It's a fantastic setup for balance and grip.
IMO, street tire setup is pretty flexible. I run the stock C4S size 225/40f and 285/30r Conti EC DW and they perform fine on the road. There are 20 other tires that I think would perform similarly. And I've driven on 295/30 rears, and noticed no difference in performance or grip on the street. (I drive conservatively on the street.)
But on the track, you immediately understand the need to choose good rubber and sizes for your driving style and skill. My 225f 285r street tires had tons of understeer on the track, and howled noisily through all corners. I can't say enough good things about my upgraded setup to RE-71's with more width up front and less in the rear.
Me too. My track setup is RE-71R 235/40/18 front, 275/35/17 rear on 996TT wheels on my 993 C4S. It's a fantastic setup for balance and grip.
Originally Posted by e9stibi
Another data point: I run 275/35/18 on 11" 996 Turbo rims on my C4S for years and really like the overall balance, particularly on the racetrack.
snowbird, e9stibi and anyone else--if you have pics of how the 275/35 tires look on 11" would you mind posting up? A search wasn't very productive but did read this. thanks!
I looked at my Hoosiers A7 on 10" wheels yesterday. Interestingly, they had rim protection and pretty pronounced one at that. They also looked flat-walled on both 10" and 11" rims that a competitor is running. And it's pretty well esteblished that they are slightly faster on 11s.
Now, this is not the fairest comparison as it's a R tire. But the fast street tire cars run 245 RE7-1Rs on 9" rims.
Below are couple pics of A6s on 11" rims showing what I mean. I'm beginning to think, however, that some rims are just made to have the lip stick out, like the pictures of BBS above or the RHs I had. Which I don't like, nor understand. i mean, why? Is it a good look to have a wheel lip out that much?
Thanks all. Went to order RE-71R but maybe stuck with PS2 given 11" rears. AD08R's in 295/30 unavailable or out of production it seems too. Will search 285 RE-71R stretched on 11's.
Good luck
I always ran 295 /235 street and 275 / 235 DE day on my 4S
Re71s GREAT for dry weather max grip.
285s work well on my gt3 with 11" rear.
I feel your pain about AD08S out of stock
I bought the last two 295-30 in the county 2 months ago.
Different tires makes have different width measurements showing the same size number. 285 sumis is not the same width as PS2 as an example.
Good point. Let me be more specific specific. I am running NT01s and Federal RSR RR in 275/35/18 on the 996 Turbo Hollow spokes. The Federals run about 10 mm wider than NT01.
09-23-2017, 05:36 PM
