Attesa

[KISIN]

Hey guys, need some direct answers...

If i have a GTR (doesnt matter which, 32/3/4) most people say have the same wheels (sizes) front and back. Now what if i put wider wheels at the back ? How and in what way will this influence the AWD system ? Is there a limit on how much i can go wider?

What about if i use the same size tyres with different width wheels ?

Any info is appreciated.

[blind_elk]

With differing widths, you will have problems matching rolling diameters front and rear. That will upset ATTESSA.

Same size tyre on a wider wheel will result in a slightly reduced rolling diameter. That will upset ATTESSA.

[djr81]

Hey guys, need some direct answers...

If i have a GTR (doesnt matter which, 32/3/4) most people say have the same wheels (sizes) front and back. Now what if i put wider wheels at the back ? How and in what way will this influence the AWD system ? Is there a limit on how much i can go wider?

What about if i use the same size tyres with different width wheels ?

Any info is appreciated.

This sort of question gets answered incorrectly too often.

You need to match the rolling diameters of the wheels front & back for the ATTESSA system to work correctly. One of the key parameters in the system is measuring wheelspeed (all of them) & comparing them to detect wheelspin. Mismatching front/rear diameters can trick the system into thinking you have wheelspin. The system then clamps the wet clutch (ie the ATTESSA clutch) which because you have mismatched wheel diameters puts undue strain on your drivetrain.

However there is a small tolerance built in so it doesn't have to be millimetre perfect.

But the important thing to note is this:

GT-R's have poor weight distribution & understeer when pushed. If you put wider wheels on the back you will degrade the handling of the car. Which presumably is not something you would set out to do.

With regard to wheels you need to be careful with widths & offsets. Too many people have got this wrong & ended up with useless rims & tyres. Sizes & offsets vary with models.

So, in summary. BAD IDEA. DON'T DO IT.

[KISIN]

Excuse the lack of knowledge, but what do you mean by "upset attessa" ? Can you have CONSTANT AWD with 50:50 front/back split ? For Arguments sake what would happen if i put a 13" wide rim up front and 9" rim at the back (both 19") ?

[Risking]

No you cant have a 50/50 split.

It WILL destory front diff's transfer cases and so forth.

Been there done that as have many others in the past.

You cant run a variance line that.

[R33_NICK]

the GTR is usually rear-wheel drive when standing still or when you drive normally and it only kicks in when you start to push it hard like accelerating out of a corner or when launching. so when your entering the corner, it enters like a RWD but when the throttle is pressed, the front grip gradually comes in and give the AWD advantage. basically the GTR has the advantages of both FR and AWD and only the weight is holding it back.

as for the ATTESSA upset, dont forget that the suspension and tyres are tuned and chosen together from factory to match the ATTESSA's characteristics so changing these two and even the power output will also change how the system behaves but if the tyres you chose are better than factory or if you can tune the suspensions to match the changes, it will still work and you might be able to take advantage of the 4WD system easily.

Edited March 7, 2009 by R33_NICK