I'm confused! Yes or No?

InTheNightKitchen · 07-22-2009, 05:16 PM

We are looking to step our game up for autocross. We see that some people are running aggressive setups on the stock suspension without fender rolling, no rubbing issues, and with/without spacers.

Here's what we are looking at:

18x8.5 +38 front with 235 or 245 or 255

18x9.5 +45 or +62 rear with 255 or 265

We'd really love to get the 265 in back, assuming it's a narrow tire. As we understand, same size different make does not mean equal.

Could you recommend a balanced yet aggressive staggered or non-staggered package for us. Any info I've forgotten please let me know.

nordique14 · 07-22-2009, 05:31 PM

I run 235/40/17 on 8.5" ET40 rims and required fender roll front and rear. Rears still have a touch of rub to them. I run a stock suspension.

arok · 07-22-2009, 05:33 PM

18x9.5 +45 will rub in the rears with 255. i'd go with a higher offset.

PC Valkyrie · 07-22-2009, 09:58 PM

Quote:

Originally Posted by nordique14

I run 235/40/17 on 8.5" ET40 rims and required fender roll front and rear. Rears still have a touch of rub to them. I run a stock suspension.

Really? I have 235/40 R17 tires on 8x17 ET40 OZ Ultraleggera rims on all 4 corners and there is not a hint of rubbing. And I run this setup on track/lapping events. I have stock suspension. Does that extra 0.5 inch of rim width make that much difference?

sootyvrs · 07-23-2009, 02:40 AM

Quote:

Originally Posted by PC Valkyrie

Really? I have 235/40 R17 tires on 8x17 ET40 OZ Ultraleggera rims on all 4 corners and there is not a hint of rubbing. And I run this setup on track/lapping events. I have stock suspension. Does that extra 0.5 inch of rim width make that much difference?

0.5 inch = 13mm so that on 8.5" rim it will stick out the fender another 6.5mm.

For an 8.5" rim to stick out the same as an 8" rim ET40 you would need 8.5" ET46 (ET46.5 to be more precise

)

fmxomar · 07-23-2009, 03:00 AM

everything you listed here will rub i know for a fact.

18x8.5 with a +38 offset can even rub on hard corner / compression with a 225

except the 18x9.5 with a +62 offset you will have no trouble with that

InTheNightKitchen · 07-23-2009, 06:01 AM

Nevermind

InTheNightKitchen · 07-25-2009, 07:55 AM

Nevermind

InTheNightKitchen · 07-25-2009, 07:59 AM

Another question is there a specific method to staggering?

These are the options I'm looking at

235/40/18
255/35/18

235/40/18
265/35/18

255/35/18
265/35/18

When I use the Tire size calculator http://www.miata.net/garage/tirecalc.html, each combo seems to be really close to stock. One of these setups will only be used for autocross. I know it also depends on wheel offset and tire manufacturer. But would one be beneficial more than the other in terms of handling?

mikeo · 07-25-2009, 11:30 AM

As posted elsewhere on 1Addicts I'm running:

Front: Breyton Race GTS-R 18x8.5 w/5mm spacer (net offset et43) and 245x35 Kumho XS tires. No rubbing with stock suspension during autocross.

Rear: Breyton Race GTS-R 18x8.5 no spacer, offset et48 and 245x35 Kumho XS tires. No rubbing with stock suspension during autocross.

07-22-2009, 05:16 PM	#1
InTheNightKitchen Ignorance is Bliss? 101 Rep 484 Posts Drives: 1 of Many Join Date: Apr 2008 Location: Connecticut iTrader: (1)	I'm confused! Yes or No? We are looking to step our game up for autocross. We see that some people are running aggressive setups on the stock suspension without fender rolling, no rubbing issues, and with/without spacers. Here's what we are looking at: 18x8.5 +38 front with 235 or 245 or 255 18x9.5 +45 or +62 rear with 255 or 265 We'd really love to get the 265 in back, assuming it's a narrow tire. As we understand, same size different make does not mean equal. Could you recommend a balanced yet aggressive staggered or non-staggered package for us. Any info I've forgotten please let me know.
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07-22-2009, 05:31 PM	#2
nordique14 Major 53 Rep 1,477 Posts Drives: SGM 135i 'vert Join Date: Feb 2008 Location: Sharks Territory iTrader: (5)	I run 235/40/17 on 8.5" ET40 rims and required fender roll front and rear. Rears still have a touch of rub to them. I run a stock suspension.
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07-22-2009, 05:33 PM	#3
arok Captain 46 Rep 987 Posts Drives: BMW F30 335i M-Sport Join Date: Jan 2009 Location: San Mateo, CA iTrader: (1)	18x9.5 +45 will rub in the rears with 255. i'd go with a higher offset. __________________ 2013 BMW 335i M-Sport
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07-23-2009, 03:00 AM	#6
fmxomar Major 94 Rep 1,245 Posts Drives: bmw 135i Join Date: Jun 2008 Location: san diego, ca iTrader: (15)	everything you listed here will rub i know for a fact. 18x8.5 with a +38 offset can even rub on hard corner / compression with a 225 except the 18x9.5 with a +62 offset you will have no trouble with that
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07-23-2009, 06:01 AM	#7
InTheNightKitchen Ignorance is Bliss? 101 Rep 484 Posts Drives: 1 of Many Join Date: Apr 2008 Location: Connecticut iTrader: (1)	Nevermind Last edited by InTheNightKitchen; 07-25-2009 at 08:23 AM..
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07-25-2009, 07:55 AM	#8
InTheNightKitchen Ignorance is Bliss? 101 Rep 484 Posts Drives: 1 of Many Join Date: Apr 2008 Location: Connecticut iTrader: (1)	Nevermind Last edited by InTheNightKitchen; 07-25-2009 at 08:23 AM..
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07-25-2009, 07:59 AM	#9
InTheNightKitchen Ignorance is Bliss? 101 Rep 484 Posts Drives: 1 of Many Join Date: Apr 2008 Location: Connecticut iTrader: (1)	Another question is there a specific method to staggering? These are the options I'm looking at 235/40/18 255/35/18 235/40/18 265/35/18 255/35/18 265/35/18 When I use the Tire size calculator http://www.miata.net/garage/tirecalc.html, each combo seems to be really close to stock. One of these setups will only be used for autocross. I know it also depends on wheel offset and tire manufacturer. But would one be beneficial more than the other in terms of handling?
	Appreciate 0 Quote

07-25-2009, 11:30 AM	#10
mikeo Santa Fe Concorso 103 Rep 2,984 Posts Drives: '11 M-sport 328i, '13 X1 28i Join Date: Jul 2007 Location: Santa Fe, NM iTrader: (3)	As posted elsewhere on 1Addicts I'm running: Front: Breyton Race GTS-R 18x8.5 w/5mm spacer (net offset et43) and 245x35 Kumho XS tires. No rubbing with stock suspension during autocross. Rear: Breyton Race GTS-R 18x8.5 no spacer, offset et48 and 245x35 Kumho XS tires. No rubbing with stock suspension during autocross.
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