Tyre Choice For Gtr Rims

[Dane]

Hey Guys

The Stagea I bought has 19x8.5" +25 Rota wheels (running 245 40 19's - a bit taller than the stock 215 55 17's - however it fills the guards better)

I really dont care for Rotas and have since bought some R35 GTR wheels with no tyres

The GTR Wheels are 20x9.5" +45 FRONT and 20x10.5" +25 REAR

Being a subaru owner I know that staggered sizes on 4wd is not an issue if the rolling diamaters are the same (or within a small percentage)

I have done some searching and am lead to believe this is still true for my M35 RS 250T (Mine has an LSD)

If someone here knows for fact that i can run taller tyres on the rear of my m35 250T please let me know to save me some time!! Obviously i'm not keen on stuffing my attessa pump, but at the same time, I think the GTR R35 runs taller rear tyres? so maybe M35 can run taller rears? Im a subie guy so a bit out of my comfort zone - anyway...after the facts if anyone is sure

So with all of this in mind I need to pick some tyre sizes and would appreciate any input

keeping in mind the stock 17" size is :

Specification  Sidewall  Radius  Diameter  Circumference    Revs/km  Difference215/55-17         118mm   334mm     668mm         2100mm        476        0.0%And the car is on 19" rotas in:Specification  Sidewall  Radius  Diameter  Circumference    Revs/km  Difference245/40-19          98mm   339mm     679mm         2132mm        469        0.0%

Some quick calcs reveal I could have the following combos on the 20's

(A)

           Specification  Sidewall  Radius  Diameter  Circumference    Revs/km  DifferenceFRONT    225/35-20          79mm   333mm     666mm         2091mm        478        0.0%REAR     265/30-20          80mm   334mm     667mm         2095mm        477        0.2%

(B)

           Specification  Sidewall  Radius  Diameter  Circumference    Revs/km  DifferenceFRONT     235/35-20          82mm   336mm     672mm         2113mm        473        0.0%REAR      275/30-20          82mm   336mm     673mm         2114mm        473        0.1%

©

           Specification  Sidewall  Radius  Diameter  Circumference    Revs/km  DifferenceFRONT     245/35-20          86mm   340mm     680mm         2135mm        468        0.0%REAR      285/30-20          86mm   340mm     679mm         2133mm        469       -0.1%

Of course I could get something like a (e.g) 235/35/20 all around with the rear stretching more than the front but i want them to look in proportion...

Also I'm unsure if I will require a fairly stretched setup to run on my reasonably low Stagea (dont want to raise it)

I think i'm in for some sleepless nights before handing over the dosh for a set of tyres...

Of course tyre brands stretch differently as well and budget is another thing to keep in mind...At this stage I have not made up my mind how much I am willing to spend on tyres...If I have to run lots of camber, im going to opt for a cheaper tyre based on previous experiences with over neg 5 deg camber cars...Another thing to note is at home I have a full set of 20" 225 35 20 rubber (china brand) - therefore option A requires just 2x 265/30-20 - but these are expensive tyres at this size after checking on ebay...It never ends...lol

HELP!

Edited January 2, 2014 by Dane

[Brick]

Are you sure the rears will even fit? I could be wrong but I thought I read a while ago some one wanted to do it and found they needed 2 sets of fronts to make them fit.

But as I said I could be completely wrong haha

[KiwiRS4T]

Yes the rolling circumference has to be the same for the Attessa. Have you checked to see if the 10.5in rears will even fit? Best idea would be to get 9.5 all round with 255 or 265 all round (minimum 245 max 275). Apart from excessively stretched tyres being illegal and dangerous different stretch front and rear will give different heights and rolling circumferences.

[Dane]

Thanks for the feedback so far guys

Now I'm thinking of running 245/35/20 front and rear - I wonder how much difference in rolling diameter there would be stretching the same sized tyres over 9.5's and 10.5's - I'm thinking very negligible....Considering the real world difference of some tyres mixing brands and combos is probably not worth the risk though with the attessa in the mix.

As for the rear 10.5's yes I'm also interested to how it will fit- will trial fit with my suspension without tyres and hopefully I don't have to buy another set of 9.5's seen a few stagea with stock looking rear guards fitting the rear 09-10 GTR rims ok

The rims arrive in a few days

Edited January 2, 2014 by Dane

[scotty nm35]

It would probably just cause a little shudder through the drivetrain under high G's, hopefully not enough for the computer to fault, but it may... Probably not good for the transfer case long term, especially with extra power thrown at it.

[Dane]

Just an update, Ive fitted 245 35 20s all around to the GTR rims and then fitted to my Stag, so far so good, done a max speed of 110km and no weirdness so far -hopefully it stays that way.

[gtr jet]

Pics?

[Dane]

Pics?

http://www.skylinesaustralia.com/forums/topic/436314-my-new-daily-drive-nm35-stagea-you-may-recognise-it/

[scotty nm35]

It won't stuff the Attessa pump if the rolling diameters are the same, you won't even notice it most of the time, as the car is in rwd for a majority of the drive. You might see some vibration occasionally going around corners, or accelerating down hills. I have seen it myself. It shouldn't be a big deal, and worst case you wear the transfer clutches out eventually.

I like how they sit on the car, looks good Dane. Need Akebono 355mm brakes now to fill them.

[iamhe77]

Need Akebono 355mm brakes now to fill them.

+1. Also, need them because they feel/perform soooo much better than stock or the 350z Brembos

Edited March 5, 2014 by iamhe77