I have 7.5j wide 17" wheels on my red sapphire.
The car was fitted with 215/40 tyres all round but thought I'd try going a bit wider on the rear for better traction.
I thought I'd try some nankang ns-2r tyres as I couldn't really afford r888's and the reviews were good on em.
Because they only do odd sizes I opted for 235/40 tyres, I know the trackday tyres have a squarer shape to em but under hard acceleration the tyres are rubbing on the body inside the wheel arch.
Mainly on the top and a little on the front side, are they just too wide and I should stick with narrower tyres?
Or maybe try stiffening/raising the suspension a little?
I'm using avo gas adj shocks and -20mm springs.
What are people using on the rears on their sierras?

Cheers Paul

 

Below are 235/40/18 on the rear & 215/40/17 on the front. You need the arches cut away for these. Have used 225/40/19 but they rub on hard cornering.

 

Interesting Rod, so yours are even bigger than mine being 18's!
So under hard acceleration when it squats do your tyres rub in the arch on the body at all?
Maybe my rear suspension is too soft??
My rear arch lips have been rolled and not fouling at all.
I'll take the wheel off later and get some pics to put up

Cheers Paul

 

Ive no liners & the edges taken right back. Under hard cornering at Brunters ive heard them rub but not on the road. I have coilovers & twin rear springs the second spring will not allow more than 1" of squat. Squatting simply loses grip & hinders acceleration. I also have chassis rods joining front to rear suspension as well as a roll cage. It handles like a go-cart.

 

Cool, sounds awesome.
I too have already removed the liners.
I think my problem is too much squat...
Looks like I may end up trying a different rear suspension setup to stop this...
May end up getting some coilovers fitted.
Thanks Rod.

Cheers Paul

 

I've run 235/40 Kumho v70 all round on track earlier this year, 8 " rim, et32, coilovers, but arches have been rolled and the front ones I pull outwards frequently.
Really does depend on ride height and spring rates.

 

I run 235/40/17 on the back of mine with ET45 wheels and koni suspension and they rub very slightly on bumps when cornering with unmodded arches

8" rims on mine BTW

 

I'm thinking my -20mm springs and avo shocks ain't up to the job then and it's just squatting too much on acceleration.
Do you guys running coilovers set them up to run quite high and hard so as to minimise squatting?
What make coilovers you all using? Gaz?

Cheers Paul

 

I have Bilstein rear shock absorbers with Eibach lowered springs and run 205/40/17 Kuhmo Ecsta V70 track day tyres. The car is quite low and I have had all the arches rolled. I am only running 450bhp but before I put the Bilstein rear shocks on I did get a lot of squat down on a hard launch with the Konis. Regarding tyre sizes I tried fitting 235/35/17s on mine and even with the rolled arches they fouled on the front wings. Dont go to big is my advice.

 

Cool.
I'll only wanna be running the 235's on the rear, not the front.
On the fronts I have 215/40's so will keep the front tyres at that size.

Cheers Paul

 

What make tyre can you get in 235/35 17 ????
Never seen them ????
On my road wheels I have 225/35 17 as I have not been able to find 235 in 35 profile.

 

mate did you see big diffirence with 235 .traction better ?

 

Sorry , my mistake. They were Toyo Proxes R888 track day tyres in 235/45/17s that I bought. When I trial fitted them as I said they fouled on the front arches.Luckily I re-sold them for what I paid for them and got my fist set of Kuhmo Ecsta V70s.

 

Yes car felt better, more grip.