Hoping these new PF01’s 18x10.5 +38 will fit
Dec 16, 2019, 01:03 PM
#61
The rubbing in the back: Would you say that +38 on 18x10.5 with 295 Hoosiers is as deep as you can "sink in" the tires/wheels?
Or could you sink them deeper? The rubbing area: is that looking into the back seat or trunk area? Wonder if it is is negotiable.
So you don't use spacers in the rear obviously. And on the front after shorter springs, do you use any spacers?
The Cayman GT4 on track, was it on Hoosiers too?
Very cool outcome.
Or could you sink them deeper? The rubbing area: is that looking into the back seat or trunk area? Wonder if it is is negotiable.
So you don't use spacers in the rear obviously. And on the front after shorter springs, do you use any spacers?
The Cayman GT4 on track, was it on Hoosiers too?
Very cool outcome.
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alpinaturbo (Dec 16, 2019)
Dec 17, 2019, 07:43 AM
#63
Eh that'd work in AX, but I'd caution using the shorter sidewall 255 or in this case the 285 tire. During time trials several years back we cord the outside of these because it can't "hold" as well as the 275 with that much weight on the nose. The hoho sidewalls aren't nearly as stiff as say a BFG R1S. The perfect diameter for our geometry, weight distro, etc on Road courses is 25.5". Much below 25" and you'll run into the sidewall problems lots of us experienced back in 07+ when we tried using 255's for points back to increase power. This is especially true when you toss it or go gentle into off camber corners. Increasing negative camber got to a point where we would cord the insides on the high load straights. It's just not the tire for us. This is with Tim from hoosier on-site as well, so it wasn't a pressure issue, or a caster issue, or any of that because we were fully prepped in those TTA/TTS days. They officially admitted and recommended we run 25.3" min which is exactly what the 295 is.
The only real difference between then and now is Dallas's knuckles, but the issue is much more basic so that won't correct it I don't think.
The only real difference between then and now is Dallas's knuckles, but the issue is much more basic so that won't correct it I don't think.
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alpinaturbo (Dec 17, 2019),
Construct (Dec 17, 2019)
Dec 17, 2019, 08:22 AM
#64
Having a shorter sidewall makes no sense why it would cause excessive wear due to tire rollover, it would seem it should be opposite if that were a thing with the longer sidewall being a bigger lever. Shorter sidewall typically = stiffer sidewall. But hoosiers in general really want a bit of stretch and a lot of camber.
If you're cording the outside it really is just lacking something in a combination of camber, caster, pressure, wheel width, and roll control.
If you're cording the outside it really is just lacking something in a combination of camber, caster, pressure, wheel width, and roll control.
Dec 17, 2019, 08:36 AM
#65
EvoM Guru
iTrader: (1)
Autocross loads the tire every bit as much as road course work. It may even be harder on the tire due to the lower corner speeds and higher steering angles making the tire work harder. So if there was issues with the 285/30 on a road course that a bunch of autocross guys never had, I'd agree that there was a setup issue. The closer to a race tire you get the more critical a proper setup is so you don't hurt the tire.
Dec 17, 2019, 09:48 AM
#66
Ken Twaits uses 19's with 25 profile tire, to get stiffer (short) side wall.
The experience Balrok shared is interesting, also as it points (does not confirm as I did not ask) why John Mueller still today sticks to 275/35x18 on all Evos supported by him: he had an issue in '07, and learned how to manage it, and still manages it.
Not sure what the answer is: I feel bad to so "Permanently deform" rear quarters on a 10K mile pristine Evo, to fit 295s. Yet by all accounts, they are about as perfect of a fit as any.
The experience Balrok shared is interesting, also as it points (does not confirm as I did not ask) why John Mueller still today sticks to 275/35x18 on all Evos supported by him: he had an issue in '07, and learned how to manage it, and still manages it.
Not sure what the answer is: I feel bad to so "Permanently deform" rear quarters on a 10K mile pristine Evo, to fit 295s. Yet by all accounts, they are about as perfect of a fit as any.
Dec 17, 2019, 09:53 AM
#67
Yeah, I would agree that you have a great condition chassis that its just not possible to go backwards when you start modifying body work. A flat roll is fine but I would probably want to keep a nice evo clean now. So as we talked about and as Ive run thru a couple sets of, I would run the 255s on a 10.5. If you just decide later to toss on the 295s then that will be a great wheel but the 255 being more like a 275 will feel great.
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alpinaturbo (Dec 17, 2019)
Dec 17, 2019, 01:11 PM
#68
Common logic would, and rightly should, tell you that any tire can be "setup". Such is true for a tube frame fiberglass car at 50/50 weight. Or a custom build where the TIRE was the first part and the rest is built around it. However, with (then) Muller, Robi, a former LMS team (now DPi), Buschur, AMS, all jumping in TT with Evo's, they ALL corded the sh*t out of them, believe me these guys knew setups. So this isn't being pulled from my anus lol, I may have pics still somewhere. As I said Everyone was running the 255 tire in the beginning of the TT program at Nasa. Vettes could get away with it because they are super duper friendly on tires....where as we....are not. Combine this with the half cocked purpose cheater construction of the 255 tire when it came out (as per hoosier reps themselves) and our loads and tada, bye bye compound.
Again this is 255/18 A6's in TT/Racing conditions. Did they fix it in A7's....unlikely? If you plan to do HPDE or AX where it'll see load yes, but nowhere near the duration or HEAT, then you'll likely get away with it ok. Once we switched to 275's on the EXACT same setup on the EXACT same day we not only dropped 2 tenths but we lasted the whole weekend instead of 5 laps. YMMV, but don't say we didn't warn ya.
Again this is 255/18 A6's in TT/Racing conditions. Did they fix it in A7's....unlikely? If you plan to do HPDE or AX where it'll see load yes, but nowhere near the duration or HEAT, then you'll likely get away with it ok. Once we switched to 275's on the EXACT same setup on the EXACT same day we not only dropped 2 tenths but we lasted the whole weekend instead of 5 laps. YMMV, but don't say we didn't warn ya.
Last edited by Balrok; Dec 17, 2019 at 01:20 PM.
Dec 17, 2019, 01:47 PM
#69
Hoosier R7 is funny tire:
At Tire Rack website, 255/35x18 and 275/35x18 are listed both having 10.3" thread width.
255 has 10.8" section width and 24.8" height
275 has 10.7" section width and 25.5" height
285/30x18 has 10.6" thread width
11.6" section width, and 24.9" height
295/30x18 has 10.7" thread width
11.6" section width, and 25.3" height
As Dallas has highlighted, the 255/35x18 Hoosier R7 is unusually wide, for a 255: even with 275 but shorter.
I dare say a lot has changed since 2003-2007, when the gang was running TTA/TTS and T1, T2 and so forth in Nasa./SCCA.
Tires are much better, which puts more load but also they resist better.
Uprights from Dallas make surely a significant improvement.
And this R7 255 is literally a 275/30x18 (shorter than 275/35x18).
Toyo RR is attractive as it lasts longer, and the
285/30x18 also has 10.6" thread width and
11.3" section width height is shown as 24.8"
In conclusion:
255/35x18 Hoosier R7 and 275/35x18 Hoosier R7 section width of 10.6" and thread width of 10.3"
Are about 1" narrower, easier to fit under the barely massaged OEM rear quarters,
Compared to
285/30x18 section width of 11.6" and thread width 10.6"
295/30x18 section width of 11.7" and thread width of 10.7"
Giving up 0.3" to 0.4" of thread. Literally 3-4%.
At Tire Rack website, 255/35x18 and 275/35x18 are listed both having 10.3" thread width.
255 has 10.8" section width and 24.8" height
275 has 10.7" section width and 25.5" height
285/30x18 has 10.6" thread width
11.6" section width, and 24.9" height
295/30x18 has 10.7" thread width
11.6" section width, and 25.3" height
As Dallas has highlighted, the 255/35x18 Hoosier R7 is unusually wide, for a 255: even with 275 but shorter.
I dare say a lot has changed since 2003-2007, when the gang was running TTA/TTS and T1, T2 and so forth in Nasa./SCCA.
Tires are much better, which puts more load but also they resist better.
Uprights from Dallas make surely a significant improvement.
And this R7 255 is literally a 275/30x18 (shorter than 275/35x18).
Toyo RR is attractive as it lasts longer, and the
285/30x18 also has 10.6" thread width and
11.3" section width height is shown as 24.8"
In conclusion:
255/35x18 Hoosier R7 and 275/35x18 Hoosier R7 section width of 10.6" and thread width of 10.3"
Are about 1" narrower, easier to fit under the barely massaged OEM rear quarters,
Compared to
285/30x18 section width of 11.6" and thread width 10.6"
295/30x18 section width of 11.7" and thread width of 10.7"
Giving up 0.3" to 0.4" of thread. Literally 3-4%.
Dec 17, 2019, 03:56 PM
#70
I just wouldn't run them in any kind of track day at his power/grip levels. And if you do bring 2-3 sets. R's maaaay do better but since the construction is the same, and the construction is the problem - I doubt it. Regarding fender mod, it's like any other mod. Do you wanna go fast, and do you wanna last 
There's only so much physics you can bend until you either break the outside fender or the inner fender for fitment. With all the $ dumped into the rest of his mods, it'd be a shame to see it held back at this point to keep a VERY non-stock car appear ......stock?
Ya since Nasa gave a +5 to RR's for 2020, then you get a +3 for 275's.....it does make one think.
There's only so much physics you can bend until you either break the outside fender or the inner fender for fitment. With all the $ dumped into the rest of his mods, it'd be a shame to see it held back at this point to keep a VERY non-stock car appear ......stock?Ya since Nasa gave a +5 to RR's for 2020, then you get a +3 for 275's.....it does make one think.
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alpinaturbo (Dec 18, 2019)
Dec 17, 2019, 09:06 PM
#71
You do bring up a good point, we can talk about what a tire should do given all other equivalencies in construction but the reality is we don't know whats inside the 255 vs the 275. Maybe it does work different with the Hoosier. The 285 and 295 A7 is a tire I know better than most here (I've gone thru several sets a year since it came out) but the 255 R7 I wont claim intimate knowledge. Only what it should be on paper. There certainly could be a weird issue with its construction being a cheater tire.
Whats the tire load rating difference between them? I haven't checked that but will pull it up tomorrow to compare if no one else does. I know its not a great figure to look at but maybe it'll tell us something.
Also, I may be out there... but I don't really listen to what these old guys who don't really do much real racing any more think. New ideas and approaches come out and those guys really cant seems to think beyond what they decided was perfect 10 years ago. Things have to continually change to grow and there is no such thing as one way. I'll try just about anything and have over the last 20 years and picking what works and throwing out what doesn't is important but so is continually trying new things but willing to go back if its not better regardless of money spent. And im not just talking Autocross, Im talking about every customer I discuss setup with. Bounce ideas around, they try stuff, I try stuff. We all learn things and try and approach these ideal scenarios based on a cars needs.
Edit: Ive also been drinking sooo
Whats the tire load rating difference between them? I haven't checked that but will pull it up tomorrow to compare if no one else does. I know its not a great figure to look at but maybe it'll tell us something.
Also, I may be out there... but I don't really listen to what these old guys who don't really do much real racing any more think. New ideas and approaches come out and those guys really cant seems to think beyond what they decided was perfect 10 years ago. Things have to continually change to grow and there is no such thing as one way. I'll try just about anything and have over the last 20 years and picking what works and throwing out what doesn't is important but so is continually trying new things but willing to go back if its not better regardless of money spent. And im not just talking Autocross, Im talking about every customer I discuss setup with. Bounce ideas around, they try stuff, I try stuff. We all learn things and try and approach these ideal scenarios based on a cars needs.
Edit: Ive also been drinking sooo
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alpinaturbo (Dec 18, 2019)
Dec 18, 2019, 08:06 AM
#72
How does the 275 RR hold up on track?
Dec 18, 2019, 11:10 AM
#73
Dallas, Balrok,
Thank you for honest and direct, but respectful sharing of experiences and ideas.
Dallas: load ratings, I looked them up for R7 255 275 285 and 295
255/35x18 R7 1047 lbs
275/35x18 R7 1201 lbs
285/30x18 R7 1168 lbs
295/30x18 R7 1235 lbs
The 255/35x18 does stand out as being rated lower, more similar to smaller diameter tires.
Interestingly some are rated very high,and virtually same tire in contrast much lower:
275/40x17 R7 1433 lbs.
versus
275/35x17 R7 1135 lbs
285/30x18 seems a very worthy size to discuss with Hoosier and Toyo, vs 255/35x18 and 275/35x18.
It is lower(smaller diameter) but because of that it fits easier inside the wheel-wells, and yet presents a generous contact path. Its also been widely used by many Evo competitors.
Thank you for honest and direct, but respectful sharing of experiences and ideas.
Dallas: load ratings, I looked them up for R7 255 275 285 and 295
255/35x18 R7 1047 lbs
275/35x18 R7 1201 lbs
285/30x18 R7 1168 lbs
295/30x18 R7 1235 lbs
The 255/35x18 does stand out as being rated lower, more similar to smaller diameter tires.
Interestingly some are rated very high,and virtually same tire in contrast much lower:
275/40x17 R7 1433 lbs.
versus
275/35x17 R7 1135 lbs
285/30x18 seems a very worthy size to discuss with Hoosier and Toyo, vs 255/35x18 and 275/35x18.
It is lower(smaller diameter) but because of that it fits easier inside the wheel-wells, and yet presents a generous contact path. Its also been widely used by many Evo competitors.
Dec 18, 2019, 11:18 AM
#74
I just checked Toyo RR, and to add insult to injury:
Toyo RR 275/40x17
Section width 10.9"
Thread width 10.5"
Overall Diameter 25.7"
While Toyo RR 275/35x18 (on my wheels now, PF01 18x10.5 +38)
Section width 10.9"
Thread width 9.9"
Overall diameter 25.6"
Toyo RR 285/30x18
Section width 11.3"
thread width 10.6"
Overall Diameter 24.9"
The Toyo RR 275/40x17 seems like a "Value Proposition" in terms of thread patch: wide 10.5" and tall 25.7".
Maybe sidewall is too tall, and maybe even on 17x10 wheels they are less desirable?
I don't know.
Originally I ran 275/40x17 on 17x9.5 +38 NT03. Its "all I knew" and never compared directly to 275/35x18.
Toyo RR 275/40x17
Section width 10.9"
Thread width 10.5"
Overall Diameter 25.7"
While Toyo RR 275/35x18 (on my wheels now, PF01 18x10.5 +38)
Section width 10.9"
Thread width 9.9"
Overall diameter 25.6"
Toyo RR 285/30x18
Section width 11.3"
thread width 10.6"
Overall Diameter 24.9"
The Toyo RR 275/40x17 seems like a "Value Proposition" in terms of thread patch: wide 10.5" and tall 25.7".
Maybe sidewall is too tall, and maybe even on 17x10 wheels they are less desirable?
I don't know.
Originally I ran 275/40x17 on 17x9.5 +38 NT03. Its "all I knew" and never compared directly to 275/35x18.
Last edited by alpinaturbo; Dec 18, 2019 at 07:18 PM.
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