Will non standard tire size mess up traction control?

jbh · 06-20-2010, 09:48 PM

If I run different size tires will it throw off the traction control on my Z4M, as in results you dont want while driving normal? On my previous car, 350Z, if the non stock tires had a 3% difference from front to back size, over the stock size it would throw the computer off with unusual results.

Finnegan · 06-20-2010, 11:01 PM

The 3% rule pretty much applies here too, and affects ABS as well.

What are your goals, what do you want to run, and which wheels?

jbh · 06-21-2010, 06:00 AM

This would only apply to my second set of wheels for AutoX/Track.

I just purchased a set of stock Z4M wheels so the size is the same. I was planning to use on the front 245/45 18 star spec tires (I have 4 tires in the garage now from a previous car) with the stock 255/40 18 rears.

But if I wanted to run the same 245/45 18 tires in back, which may not be a great idea since they are actually smaller, but they are tires I already have would that work. I saw a link to a tire size calculator once before. If I was to purchase new Z1 star spec rears at 255/35 18 or 265/35 18 I am not sure it would work with the fronts at 245/45 18 but they do sell a 245/40 18.

I have my regular set of wheels and tires, all stock, that are my daily drivers. I was just wanted to get the rest of the life out of my Z1 star specs for AutoX. If that does not work I can just run the standard size rears.

jbh · 06-23-2010, 09:30 PM

Just so I am clear, is it no more than a 3% difference from the front tire and rear tire size? For example on this site it says my 245/45 r18 and 255/35/ r18 have a difference of 6.2% so no good? But 245/40 r18 and 255/35/ r18 have a difference of 2.7% so barely ok? These were all based on Z1 star spec sizes.

http://www.tacomaworld.com/forum/tirecalc.php

Finnegan · 07-05-2010, 06:23 PM

Correct, no more than 3%. 2.7% s/b fine.

This is the calculator I've used....http://www.1010tires.com/TireSizeCalculator.asp But it looks like the one you found works just fine too.

jbh · 07-05-2010, 06:48 PM

Thanks, earlier today I put on my old star specs, square setup of 245/45 R18. No issues driving it today for the traction control. I was hoping to run the 245/45 up front and a 255/35 or 265/35 out back but it is too much difference. But my old autox tire setup seems like it will work for competition uses until I finish them off.

On another note I do get some kind of rub when wheel is turned all the way right turning slowly. Does not do it fully turned left. The 245/45's are taller than most peoples 245/40 they are running when they run a 245 front tire. These were just tires I already had and will only use them for autoX.

fr8tdog · 07-08-2010, 03:44 AM

Quote:

Originally Posted by jbh

Thanks, earlier today I put on my old star specs, square setup of 245/45 R18. No issues driving it today for the traction control. I was hoping to run the 245/45 up front and a 255/35 or 265/35 out back but it is too much difference. But my old autox tire setup seems like it will work for competition uses until I finish them off.

On another note I do get some kind of rub when wheel is turned all the way right turning slowly. Does not do it fully turned left. The 245/45's are taller than most peoples 245/40 they are running when they run a 245 front tire. These were just tires I already had and will only use them for autoX.

I run Nitto 555r Drag radials in 285 size in the rear with absolutely no problems. I have stock front. The only problem I have is neck problems from perfect traction

Thisisdudewhoru · 07-09-2010, 05:20 PM

Do the 285/35/18 nt555r's fit on stock wheels with no issues? rubbing?

06-20-2010, 09:48 PM	#1
jbh Private First Class 18 Rep 156 Posts Drives: 2007 Z4M Join Date: Aug 2009 Location: Fort Worth iTrader: (2)	Will non standard tire size mess up traction control? If I run different size tires will it throw off the traction control on my Z4M, as in results you dont want while driving normal? On my previous car, 350Z, if the non stock tires had a 3% difference from front to back size, over the stock size it would throw the computer off with unusual results.
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06-20-2010, 11:01 PM	#2
Finnegan Dog Listener 703 Rep 7,850 Posts Drives: Z4M/. Z3M, E36/46 M3 Join Date: Oct 2008 Location: Teaching the dog to slalom iTrader: (22)	The 3% rule pretty much applies here too, and affects ABS as well. What are your goals, what do you want to run, and which wheels?
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06-21-2010, 06:00 AM	#3
jbh Private First Class 18 Rep 156 Posts Drives: 2007 Z4M Join Date: Aug 2009 Location: Fort Worth iTrader: (2)	This would only apply to my second set of wheels for AutoX/Track. I just purchased a set of stock Z4M wheels so the size is the same. I was planning to use on the front 245/45 18 star spec tires (I have 4 tires in the garage now from a previous car) with the stock 255/40 18 rears. But if I wanted to run the same 245/45 18 tires in back, which may not be a great idea since they are actually smaller, but they are tires I already have would that work. I saw a link to a tire size calculator once before. If I was to purchase new Z1 star spec rears at 255/35 18 or 265/35 18 I am not sure it would work with the fronts at 245/45 18 but they do sell a 245/40 18. I have my regular set of wheels and tires, all stock, that are my daily drivers. I was just wanted to get the rest of the life out of my Z1 star specs for AutoX. If that does not work I can just run the standard size rears.
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06-23-2010, 09:30 PM	#4
jbh Private First Class 18 Rep 156 Posts Drives: 2007 Z4M Join Date: Aug 2009 Location: Fort Worth iTrader: (2)	Just so I am clear, is it no more than a 3% difference from the front tire and rear tire size? For example on this site it says my 245/45 r18 and 255/35/ r18 have a difference of 6.2% so no good? But 245/40 r18 and 255/35/ r18 have a difference of 2.7% so barely ok? These were all based on Z1 star spec sizes. http://www.tacomaworld.com/forum/tirecalc.php
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07-05-2010, 06:23 PM	#5
Finnegan Dog Listener 703 Rep 7,850 Posts Drives: Z4M/. Z3M, E36/46 M3 Join Date: Oct 2008 Location: Teaching the dog to slalom iTrader: (22)	Correct, no more than 3%. 2.7% s/b fine. This is the calculator I've used....http://www.1010tires.com/TireSizeCalculator.asp But it looks like the one you found works just fine too. Last edited by Finnegan; 07-05-2010 at 06:32 PM..
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07-05-2010, 06:48 PM	#6
jbh Private First Class 18 Rep 156 Posts Drives: 2007 Z4M Join Date: Aug 2009 Location: Fort Worth iTrader: (2)	Thanks, earlier today I put on my old star specs, square setup of 245/45 R18. No issues driving it today for the traction control. I was hoping to run the 245/45 up front and a 255/35 or 265/35 out back but it is too much difference. But my old autox tire setup seems like it will work for competition uses until I finish them off. On another note I do get some kind of rub when wheel is turned all the way right turning slowly. Does not do it fully turned left. The 245/45's are taller than most peoples 245/40 they are running when they run a 245 front tire. These were just tires I already had and will only use them for autoX.
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07-09-2010, 05:20 PM	#8
Thisisdudewhoru Captain 82 Rep 698 Posts Drives: 16 BSM 340i Join Date: Mar 2010 Location: 423 iTrader: (1)	Do the 285/35/18 nt555r's fit on stock wheels with no issues? rubbing? __________________ '16 BSM 340i M Sport + Track Pack.:.M Perf Exhaust.:.Polished BBS RS-GT.:.JB4.:.BMS Intake.:.H&R Sport.:.
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