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Anyone running 245/40/18 and 275/40/18s with x73 suspension? it'll lower the car about 1/3rd of an inch over stock sized tires. I already scrape the underside of the car often enough.. stock size Yokos are out of stock. I'm on 9" and 10" wide wheels.
 

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2008 Cayman RS (my version) and non-RS 2010 GT3
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Anyone running 245/40/18 and 275/40/18s with x73 suspension? it'll lower the car about 1/3rd of an inch over stock sized tires. I already scrape often enough.. stock size Yokos are out of stock. I'm on 9" and 10" wide wheels.
I do for my track wheels…those shouldn’t rub tho…
 

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Oh I meant I scrape the car on the ground (and curbs on track if I put two off) because its so low. the tires don't rub the car at all.
This will be fine. Also depends on what offsets you are running if you want to go wider.
Hankook Rs4 and Yoko A052 work in 245/40/18 and 275/40/28
RE-71R in 255/35/18 and 275/35/18
Hankook z214 (DOT slicks) in 245/35/18 and 275/35/18
Nitto NT01 in 245 and 275 work

For those with more than 3 degrees of camber you can get Hoosier R7 245/40/18 and 295/40/18

Note: especially with Hoosiers, look at the exact measurements (tread width/etc) and don’t go based on the spec eg 245. For instance, the tread of the R7 in 255/35/18 and 275/35/18 are essentially the same.
 

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What offsets ye’all running? Generally I like to go as far out as I can without sticking out… I have a +30mm offset with a 10”… I’m sure I could still go another 5mm.. I’m not a stance guy but let’s face it flush is more aggressive looking… gotta function first tho
 

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There are variables that each of us include or exclude in this tire size issue. I like the 255/35/18 f and 275/35/18 r of various makes. I have a set of Titan 7 TS-5 mounted with RE71R size 255/35/18f and 275/35/18r. These forged wheels are 9 in wide in front with an offset of 46 and 10 in in the rear with an offset of 35. Also a set of Signature SV-104's forged wheels again are 9 in wide with an offset of 47 f and 10 in wide offset of 35 r, mounted with Hoosier A7 255/35/18 f and 275/35/18 r. Then a set of OEM 8 in f and 9 in r with Michelin PS4's 245/35/18 f and 275/35/18 r. I really like the RE71/Hoosier setup with my car as I am using a Wavetrac LSD which puts a little more understeer in f so a wider tire footprint neutralized this inherent Porsche understeer along with a additional push of the LSD. The 35s sidewalls also seem to flex less and have higher spring rate than 40s so turn in and tire roll is slightly less. I do have Ohlin's R&T which have a spring rate of 400 lbs/in f and 458 lbs/in r which helps keep the car from scraping on bumpy roads as the 35 sidewall tires sit the car lower to the ground. When using my car daily, I use 15 (Ohlin rebound/compression) clicks from full stiff in front and rear. Currently I'm running -2.8 degree camber f and -2.5 degrees rear. Hoosier recommends at least -3.0 camber f but I find -2.8 good enough for my use without additional outside shoulder front tire wear.
All of the above factors work well together on my car of about 300 HP at the rear wheels. More HP at the rear wheels tend to need a wider rear tire patch.
 

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With a 35/18 aspect ratio you're at a 0.65" front and 0.9" rear drop in ride height compared to stock sizing. That's too low imo, especially with X73 suspension.

I pulled the trigger on 245/40/18 and 275/40/18 Yoko A052s. They only lower the car about 0.25-0.3" from stock. I'm also on Titan7s, 9"s and 10"s. I'm hoping a little more meat won't overheat quite as quickly as a bonus.
 

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35’s would just stiffen the side to side play more so… if you have 9/10’s I would have done the 255/285 and then I would have then gone 35’s(for the track). Sometimes you have to play around some. I have 245/285x35/19’s… work exceptional.
 

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With a 35/18 aspect ratio you're at a 0.65" front and 0.9" rear drop in ride height compared to stock sizing. That's too low imo, especially with X73 suspension.

I pulled the trigger on 245/40/18 and 275/40/18 Yoko A052s. They only lower the car about 0.25-0.3" from stock. I'm also on Titan7s, 9"s and 10"s. I'm hoping a little more meat won't overheat quite as quickly as a bonus.

I'm thinking about doing the same, any issue with increasing by 10 on stock wheels? Thanks
 

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245/75s fit on a 9/10" wheel nicely. 235/265 is a little stretched.

Anecdotally, I wasn't much faster on the 247/275 setup and in fact was slower on some tracks than my prior year running stock sizes. This is with A052s which are known to like a wide wheel so maybe the 235/265s were a better fit. Hard to say and I doubt im consistent enough for this to be very controlled. Either way, the change wasn't dramatic.
 

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Anyone running 255/40/18 front w/ 285/40/18 rears on 9"/10" wide wheels? I'm hunting for One Lap of America tires so need a Michelin PS4S or Conti ECS type tire.
The rack doesn’t have them? Or are you asking if they’ll fit? Yes they’ll fit on those widths however up front you’ll probably stick out a little because you can’t get enough neg camber with the oem LCA’s…I have 245/285 but I’ll go 255/295 next
 

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The rack doesn’t have them? Or are you asking if they’ll fit? Yes they’ll fit on those widths however up front you’ll probably stick out a little because you can’t get enough neg camber with the oem LCA’s…I have 245/285 but I’ll go 255/295 next
I'm looking for feedback on fitment. That's good. I'm running GT3 LCAs and have about -2.6deg of front camber so outta work it sounds like.
 
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