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      03-20-2011, 08:19 PM   #1
3002 tii
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Do Star Specs Run Wide?

Thinking of running 255/35-18 on all 4 corners on my 3.0si coupe, NOT lowered... stock suspension with 18x8.5 et42 square. Anyone forsee a problem, ie rubbing?
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      03-20-2011, 08:43 PM   #2
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teh 255s will rub up front ALOT... on the strut. They will not fit.

Personal experience with a 255/40 17 on a 17x8 et 41, no way they will fit. Sorry
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      03-20-2011, 08:44 PM   #3
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^ what about with a spacer?


:edit:
NM, just noticed 255 up front.
They will definitely be a problem.
/edit
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      03-20-2011, 08:44 PM   #4
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Dunlop Direzza Star Specs run wide but not as much as Nitto NT01s.
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      03-20-2011, 08:47 PM   #5
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Quote:
Originally Posted by inTgr8r View Post
^ what about with a spacer?


:edit:
NM, just noticed 255 up front.
They will definitely be a problem.
/edit

also, i am never a proponent of spacers.
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      03-20-2011, 08:58 PM   #6
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Quote:
Originally Posted by wassup61 View Post
teh 255s will rub up front ALOT... on the strut. They will not fit.

Personal experience with a 255/40 17 on a 17x8 et 41, no way they will fit. Sorry
Thought it'd fit based on the wheel/tire calculator here:

http://www.e90post.com/forums/forumdisplay.php?f=12

entered current specs:
8.5 width, 42mm offset, 225/40/18 tire (what I'm actually running now)

new specs:
8.5 width, 42mm offset, 255/35/18 tire

and it spit out:
THE SAME clearance on the strut side, and the outside edge of the wheel will extend to THE SAME point as the stock wheel
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      03-20-2011, 09:15 PM   #7
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Yes... The wheel will fit, spec looks identical but I thought you're asking about tires? Going from 225 to 255 will be wider for sure..
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      03-20-2011, 09:22 PM   #8
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That calculator doesn't take into effect that ACTUAL width of the tire though.

For example. Hankook V12s are not was wide as Start Specs
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      03-20-2011, 10:33 PM   #9
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Quote:
Originally Posted by JDN34 View Post
Yes... The wheel will fit, spec looks identical but I thought you're asking about tires? Going from 225 to 255 will be wider for sure..
Correct, all else bring equal (keeping rims at 8.5" width with 42mm offset), will going from 225/40 to 255/36-18 on the fronts be an issue?

Tires now are V12s, tires bring considered are Star Specs...
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      03-21-2011, 11:07 AM   #10
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wheel specs aside, you're looking at an overall increase of 30 mm (possibly more depending on tire mnfr) in rubber only. essentially 15mm inside and out.

so... if your setup with 225's still have roughly 3/4" inner clearance (i say 3/4" due to 15mm ~ 5/8", plus a bit for deflection in hard cornering), a 255 will work.

keep in mind that you'll still need 15mm worth of clearance on the outside of the tire for full lock in steering as well.
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      03-21-2011, 11:20 AM   #11
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Quote:
Originally Posted by v3.0si View Post
wheel specs aside, you're looking at an overall increase of 30 mm (possibly more depending on tire mnfr) in rubber only. essentially 15mm inside and out.

so... if your setup with 225's still have roughly 3/4" inner clearance (i say 3/4" due to 15mm ~ 5/8", plus a bit for deflection in hard cornering), a 255 will work.

keep in mind that you'll still need 15mm worth of clearance on the outside of the tire for full lock in steering as well.
Thanks... for reference, APEX posted this guide here which leads me to believe that spacers/neg camber would be needed:

http://www.zpost.com/forums/showthread.php?p=9014263

But checking different e46 setups, ///Mspired ran the same setup with a 1/2" wider rim (18x9" et42) and only the rears were an issue (fronts were close to strut), so I'm thinking a 8.5" wide rim should be ok?

http://www.e46fanatics.com/forum/sho...=665774&page=2


Perhaps, I should go with 255s but stick to V12s just because they are cheaper, still a "good" tire, and they don't run as wide as the Direzzas...
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      03-21-2011, 01:17 PM   #12
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i trust the APEX site over VMR's fitment, and here's why...

when asked whether or not that e46 was modified in any way, Kevin @ VMR claimed that only a fender rolling had occured and there were no problems at all. the issue i have with this is that car is clearly lowered and the front has more negative camber than the rear does.

now, either the addition of the 255's on that car were done after the other mods that had already been done and VMR cleverly "forgot" that suspension mods were probably a main contributor to those tires fitting in conjunction with rolling the fenders...

or...

half the people on this forum with thousands of dollars in suspension kits and/or lowering springs just found out that had they rolled their fenders first the car would have lowered itself.

i should mention that i have done business with VMR (charles) and was pleased with the result... but i feel, for the above reasons, that the information on that e46 page is suspect.
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      03-21-2011, 01:30 PM   #13
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the 255s will rub at full lock. I promise you your fender liners will not be happy
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      03-21-2011, 01:33 PM   #14
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Apologies in advance if I'm coming off stubborn. It's just I can't tell if apex recommendations are based on them trying to be more safe without actual confirmation of pushing the limits... especially when other e46 owners have been able to pull it off. If camber plates would resolve this, I may just do that. But if rub is unavoidable, I'll go with the 245/35...
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      03-21-2011, 04:22 PM   #15
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Quote:
Originally Posted by Dubbedown View Post
Apologies in advance if I'm coming off stubborn. It's just I can't tell if apex recommendations are based on them trying to be more safe without actual confirmation of pushing the limits... especially when other e46 owners have been able to pull it off. If camber plates would resolve this, I may just do that. But if rub is unavoidable, I'll go with the 245/35...
at one point you were equipped with style 197's... what tire spec were you using? did you have any clearance issues with those?

i seem to recall someone on here having a set of e9x sport wheels fitted with 235/40r18's and having outer clearance issues. an 8.0 x et34 with 235 tread width would be very similar in outer clearance to a 8.5 x et42 with 235's. 255's would certainly make it worse.
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      03-21-2011, 05:27 PM   #16
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Quote:
Originally Posted by v3.0si View Post
at one point you were equipped with style 197's... what tire spec were you using? did you have any clearance issues with those?

i seem to recall someone on here having a set of e9x sport wheels fitted with 235/40r18's and having outer clearance issues. an 8.0 x et34 with 235 tread width would be very similar in outer clearance to a 8.5 x et42 with 235's. 255's would certainly make it worse.
Correct, had 197s with 235/40 PS2's and I was rubbing on the outside on the fender liner, and the fender itself - caused slight warping. But I thought that was more of a height issue, and less about width. Thus, I thought a 35 profile would be ok...?
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      03-21-2011, 06:58 PM   #17
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I don't know, sounds to me like you're making this harder than it should be.

Since the non-M Z4s uses same offset front and rear, why not just get two 255 star specs mounted on the rims, put them up front, drive around in a big empty parking lot with decent dips to see if heavy compression and/or near full lock will cause the tires to rub? If it does, put the 255's in the back, and run 245 or 235s in the front.
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      03-21-2011, 07:30 PM   #18
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Quote:
Originally Posted by Dubbedown View Post
Correct, had 197s with 235/40 PS2's and I was rubbing on the outside on the fender liner, and the fender itself - caused slight warping. But I thought that was more of a height issue, and less about width. Thus, I thought a 35 profile would be ok...?
it may have been a height issue then, but...

235/40r18 has an overall diameter of 25.40"

vs.

255/35r18 with diameter of 25.02"

= total RADIUS difference of - 0.19"

however...

235mm --> 9.25"

255mm --> 10.03"

= outer tire difference (1/2 of overall) of + 0.39"

so...

even if you're losing 0.19" in height (to center of wheel) you'll still gain 0.39" (outer clearance from centerline of wheel), and because the arc trajectory of the wheel does not change, the 255 will most likely have clearance issues on the liner.

side note: a 245/35r18 has a -0.33" RADIUS difference and a + 0.20" difference in width from the CENTERLINE, all vs. a 235/40r18.

my bet (purely based on the math) is a 245/35r18 will be the widest you can go without changing camber or suspension components on an 8.5" et42 (et40 really, since we're comparing to an 8.0" et34. the error here would be ~ 0.078", or 2mm / 25.4mm)
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      03-21-2011, 08:15 PM   #19
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v3.0, good job.

OP, please dont run 255s. It is going full retard
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      03-21-2011, 08:28 PM   #20
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Quote:
Originally Posted by The HACK View Post
I don't know, sounds to me like you're making this harder than it should be.

Since the non-M Z4s uses same offset front and rear, why not just get two 255 star specs mounted on the rims, put them up front, drive around in a big empty parking lot with decent dips to see if heavy compression and/or near full lock will cause the tires to rub? If it does, put the 255's in the back, and run 245 or 235s in the front.
lol sorry that was not my intent. how would running staggered tires on square wheels affect handling?



Quote:
Originally Posted by v3.0si View Post
it may have been a height issue then, but...

235/40r18 has an overall diameter of 25.40"

vs.

255/35r18 with diameter of 25.02"

= total RADIUS difference of - 0.19"

however...

235mm --> 9.25"

255mm --> 10.03"

= outer tire difference (1/2 of overall) of + 0.39"

so...

even if you're losing 0.19" in height (to center of wheel) you'll still gain 0.39" (outer clearance from centerline of wheel), and because the arc trajectory of the wheel does not change, the 255 will most likely have clearance issues on the liner.

side note: a 245/35r18 has a -0.33" RADIUS difference and a + 0.20" difference in width from the CENTERLINE, all vs. a 235/40r18.

my bet (purely based on the math) is a 245/35r18 will be the widest you can go without changing camber or suspension components on an 8.5" et42 (et40 really, since we're comparing to an 8.0" et34. the error here would be ~ 0.078", or 2mm / 25.4mm)
thanks, i will stick to 245s. one reason i preferred the 255s was not so much for the additional width but the fact that it retained stock height. would running shorter profile make a noticeable difference in comfort?
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      03-22-2011, 08:16 AM   #21
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245/35r18's are shorter... it'll probably feel like you've put rft's back on. i'm not so sure there won't be tramlining either. as for vanity, it'll look smaller (albeit by 1/8") in the fender opening.

honestly, dubbedown... you'll just have to try it. one thing i've heard works is to head down to your favorite tire shop and see if they have any takeoffs that they'll let you test fit. they won't let you drive much (for obvious legal reasons), but it may be a cheap alternative to buying tires you find you can't use. 245/35's are not common though, so it may be difficult to find a set locally, if even new.

are you running 255/35's on the rear now? is it feasible you could swap one to the front just to test the car's static clearance? that way, if it works parked, the confidence to try a rolling test squared will be bolstered...
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      03-22-2011, 09:58 AM   #22
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looking at wassup61's setup of 255/40r17 on 8.0" et41...

a 255/35r18 (which is damn near identical to a 255/40r17) on an 8.5" et42 will be 5mm MORE aggressive on the fender side. if he had clearance issues at the liner, you will absolutely have clearance issues in the same spot.
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