Gtr - Track Help - Tyres

[JSL]

Hi All

No no this is not a thread about what tyres i should get...

I want to know from the experience of R32 GTR drivers.. I am running a set of R34 GTR rims.. and wanting to know if the Stock 16x8 R32GTR wheels is good enough for track with a decent set of semi?? Or do i really need to move to 17"?

I have a set of lightweight 17x8.5 and 17x9.5 they near new i was wanting to sell it as the offset are not perfect...

Please advise..

[maccattack]

Whilst I run a 33 GTR not a 32, really it is irrelevent. Your tyre selection as opposed to rim selection is far more important on the track. 16" rims a perfectly good for the track. The only restriction really that you have is the amount of rubber you can fit on them. Sell your good rims and run the 16's.

[hrd-hr30]

the factory 16" wheels will be OK. And tyres are alot cheaper than 17" race rubber. I ran the standard wheels on my 32 GTR with 225/50 Bridgestone RE55S rubber at Mt Cotton Hillclimb, Bathurst Speed weekend etc, and got a 3rd outright (1st in class) at Bathurst's Mountain Straight Hillclimb, so they can't be too bad.

Saloon cars use a 225/50*16 Bridgestone RE55S as their control tyre, so cheap secondhand tyres are available around the place, and if you join their association/club, you are eligible for big discounts on new Bridgestones - like $75 per tyre off retail!

[scathing]

The only reason to get bigger rims is to fit bigger brakes under them. Otherwise all you're doing is increasing unsprung weight (unless you can score a really light set of 17's).

On the plus side, Commodore Cup cars run 245/45 R17 (or is it 235/45?) as their control tyre size. So it means that semis don't cost that much, and if you're only an amateur you should be able to find really cheap second hand ones.

If you decide to go 17" anyway........

[djr81]

If you want to compare 17's with 18's have a look at page 17 of the series of photos from the 22nd of July (Last week) at Wanneroo. They are on www.circlework.com.au at the bottom of the page. Two of the GT-R's are on 18's & one on 17's. have a look and make of it what you will...

[Beer Baron]

i dunno what to make of those pics? help a brother out.

[djr81]

I dunno either.

The only things that come to mind are:

Check the sidewall deflection on the 17's. This may be tyre pressures, or it may be due to the height of the side walls. Dunno what the psi boys on 18's were running, but mine were only 35# on account of needing to generate some temps on a cold day.

My shit box (White car on 17's) was still understeering too much. Must work harder....

[JSL]

Thanks for all the replies!!! I just wanted to make sure before i invest in a set of stock wheels..

[Duncan]

I wouldn't worry about the tyre sidewall height, semis and slicks have very hard sidewalls, nothing like road tyres.

You are better off with the smallest rims you can fit over your brakes

[JSL]

I wouldn't worry about the tyre sidewall height, semis and slicks have very hard sidewalls, nothing like road tyres.

You are better off with the smallest rims you can fit over your brakes

yea... that the thing.. i have to make sure my R33 Brembo fit in the stock R32 GTR wheels..

[Duncan]

ahh OK no the brembos don't fit under 16s...you do need the 17s....

There was a thread a while back saying someone in tas (I think) fitted the brembos under 16s but it required "relieving" the caliper, not a good idea I think.