Put 18's On And The Torque Gauge Is.....

[godzla32]

My Torque Gauge Is Not Working As It Was With The Standard Gtr Wheels Its Constantly On 10?, The Guy I Brought The Wheels Of Said The Same Thing He Reckons Something To Do With Bigger Tres On The Back? Any Truth To This And How To Fix It?

[Beer Baron]

I don't know how to fix your problem, but if you want to sell your stock BNR32 wheels, please send me a PM

Richard (sorry for the hijack)

[GTS-t VSPEC]

Yeah, I'm pretty sure that GTR's need to run the same size rim and tyre on the back and the front. I believe your only option it to change to the same size all round.

[Guest Variable]

I had the same problem on my 32 GTR a while back. Had some 3 month old 255/40 R17 Federals on the back and replaced the fronts with brand new 255/40 R17 Potenza S03's. The difference in rolling diameter was enough to put my torque gauge permantly on about 8. Put the new Potenzas on the back and everything went back to normal.

[aybee]

all four wheel/tyre combos must be the same on a gtr.

[godzla32]

mmmgtir not intersted selling the stock gtr wheels at this stage, they are too hard to find! my problem is the front wheels are 8.5inch wide and the rear are 9inch so guess i cant do much about it!

[Laurence]

There is no law against putting the same size tyres on those rims.

245's will be happy on both those widths. Commodores have 235's on 8" rims

stock BNR34s run 245/40R18 on 9" wide wheels. It is all good dude!

Trivia:... 911 turbos use different diameter front and rear tyres to preload the viscous coupling that transfers torque front to rear.

[TurboX]

  aybee said:

all four wheel/tyre combos must be the same on a gtr.

No, you can have different widths front and back but the tyres you use have to have the SAME ROLLING Diameter.

So its just a matter of getting the right aspect ratio of the tyres correct.

Its the same if you get a partly flat tyre, the torque gauge tells you something is not right by running quarter way on constantly.

[aybee]

Yeah thats true. but the whole idea is that its pretty hard to get the rolling diameters accurate enough to not piss off the car.

so unless you want to fark around, just take the proven route and match the wheels front and back.

[ferni]

if you have different size tyres on (that arn't exactly the same rolling diam), the ATTESA picks up that one set of wheels (front or back) is spinning faster than the other set, so it gives you some front torque...

everyone i know with a GTR goes for same size wheels/tyres for this reason, plus we can fit them under our gaurds

[DICKY]

keep driving & you will root the clutch pack in the transfer case !

[godzla32]

Its Too Late Now To Go The Same Wheel Witdth All Around As I Just Brought These Wheels! Is There A Problem The Attesa Being Constantly On Around A Quarter?

[ferni]

as DICKY said, if you keep driving as is you will root the clutch in the transfer case

sell them and buy new wheels or get new tyres same size - 245 all around

[godzla32]

Thanks For The Info Guys Much Apperciated, Going By What You Said Il Be Changing To 245's All Around Asap. Ferni By Puttin 245s A;; Arnd Will This Fix The Attesa?

[Rezz]

Caps lock prevention...

[ferni]

Same sized (same brand/model even better) will mean you have exact same rolling diam, so yep will fix it, wheel size doesn't matter so much, its the tyre size...

[Gav]

Hmmm....interesting thread.

Often wondered what would happen in practice with different rolling diameters front to rear.

[aybee]

the difference in wheel size may affect it though. cause when you put 245s over 9 inch wheels they will stretch more than on 8 inch. The more stretched, the less upright the sidewalls so the rolling diameter will be less.

or may be less. just a thought. can anyone clarify...

[CerealKiller]

Sorry This Is A OT, But What's With The Capitalisation Of Each New Word?

[Laurence]

Yes... that is right. It all depends how smart the computer is

If it is 8.5 vs 9.0 inch and he is using 245/40R18's and lets just assume that 8.5" gives you a perfectly straight sidewall you would have a total diameter of 653.2mm So if we stick them on 9" wheels (6.35mm wide each side) and assume (there is that word again) that the sidewalls are 100% stiff and retain their 98mm length then the according to Mr Pythagoras new effective height would be 97.98mm which is probably something I have stuffed up...

So the difference would be 0.04mm on the total diameter.