So the question is what’s the widest rear tyre you can fit on a Z32 with standard body work? Rolled arches are permitted. Who’s got them and what does it do for the traction?

 

I know I can fit 285s on my 9½JJ wheels, but will they then fit in the rear arches?

Was on the phone yesterday so didn't comment. I ran 305/30 19 for a few years, rolled/pulled/flared arches, no rubbing under extreme track use.

 

Why did I do it, because I could! This was also when I put it together for fast road use and worked great.

 

The comments from BobGenie and Z32Bolt are the most valid, wider isn't always better. The contact patch is driven by the weight, the grip is driven by compound and heat.

 

What are you looking for? Quarter mile or circuit?

Was on the phone yesterday so didn't comment. I ran 305/30 19 for a few years, rolled/pulled/flared arches, no rubbing under extreme track use.

 

Why did I do it, because I could! This was also when I put it together for fast road use and worked great.

 

The comments from BobGenie and Z32Bolt are the most valid, wider isn't always better. The contact patch is driven by the weight, the grip is driven by compound and heat.

 

What are you looking for? Quarter mile or circuit?

 

Quarter mile.

 

I guess my real question is this.

 

‘I’ve got 17” 9.5JJ rims. What is the best tyre size to give the maximum performance for a Quarter Mile?’

 

Bear in mind I only have about 370 horses and a NA diff.

Gut feeling is as set of 275/40-17 Proxes R888s

Quarter mile.

 

I guess my real question is this.

 

‘I’ve got 17” 9.5JJ rims. What is the best tyre size to give the maximum performance for a Quarter Mile?’

 

Bear in mind I only have about 370 horses and a NA diff.

Gut feeling is as set of 275/40-17 Proxes R888s

 

275/40 sounds right. R888 / Nitto / Mickey THompsons depending on the regs for your series

 

I will be going for the same size for qtr mile on 17x9.5

My car is still on the ramps so not quite what they will look like but these are 295.30.18 wheels are 10.5 with +11 offset. Going to be just about right methinks :)

My car is still on the ramps so not quite what they will look like but these are 295.30.18 wheels are 10.5 with +11 offset. Going to be just about right methinks :)

 

Nice wheels there bob, what are they?

Quarter mile.

 

I guess my real question is this.

 

‘I’ve got 17” 9.5JJ rims. What is the best tyre size to give the maximum performance for a Quarter Mile?’

 

Bear in mind I only have about 370 horses and a NA diff.

Gut feeling is as set of 275/40-17 Proxes R888s

 

The yanky boys use the stock 16" rear for drag racing, which is the same as the UK spec rears. Allows for plenty of sidewall, sidewall flex reduces wheelspin.

Nice wheels there bob, what are they?

 

Yes I love em. They're Volk SE37 :)

Quarter mile.

 

I guess my real question is this.

 

‘I’ve got 17” 9.5JJ rims. What is the best tyre size to give the maximum performance for a Quarter Mile?’

 

Bear in mind I only have about 370 horses and a NA diff.

Gut feeling is as set of 275/40-17 Proxes R888s

Do you need to be "road legal"??

The Mickey Thompson ET Street Radial is the best tyre by a country mile.

 

It is allowed by Santa Pod as a "street " tyre.

When used properly it will hold in excess of 500bhp.

It will allow you to launch properly ie at max torque revs and shift correctly at max power revs.

End of discussion.

One additional bit.

If all you have is some 9.5J rims then they will sit OK on them. BUT if you had some 10" then they will sit even better.

Im not quoting from on line tyre calculators Im telling you as an owner of a pair .Mine are currently not on 10"s but either 9 or 9.5 ...They are not at home so I cant check but they are as flat as they could be.

I know finding some 10" 17s isnt easy but it would be worth the effort.Im going to use my 10" soon

I've only been to santa pod twice so know very little about drag tyres, do you want some flex then? I know when you see the wheelie pulling yanks they have massive sidewalls that ripple as they launch,

 

What about track cars?

 

Sorry to hijack a bit but I'm new to track/drag car would be useful to know for my na trackday car

 

Only measured my wheels and tyres as I had fitting issues with the front catching on the bumper,

I've only been to santa pod twice so know very little about drag tyres, do you want some flex then? I know when you see the wheelie pulling yanks they have massive sidewalls that ripple as they launch,

 

What about track cars?

 

Sorry to hijack a bit but I'm new to track/drag car would be useful to know for my na trackday car

 

Only measured my wheels and tyres as I had fitting issues with the front catching on the bumper,

 

A whole new world awaits you.

Drag tyres are drag tyres and track day tyres are.... well track day tyres.!!

Start a new thread and we can get the ball rolling

Phoenix, yes you do, with a drag radial with the right pressure in it and the right height etc. When launched correctly the alloy turns quicker than the tyre, this rolls it up and lays it against the road making a massive surface area that the car then sort of springs forwards off. If you have a 20 inch painted black, the tyre will be rock hard and will skip and spin and you don't get the launch.

Here you go sii Front 8.5 x 18 et 30 with 245 Rears 9.5 x 18 et 30 with 285 x 30

As Pete said different tyres for different things, different priorities. You will notice the big wrinkle wall tyres on drag cars, the idea being to soften the shock of launch and to allow the tyre to make the maximum contact patch, the aim of the game is maximum grip off the line. For track cars you will notice much stiffer sidewalls, this helps to maintain the car through the corners, you'd soon have issues going round track on wrinkle walls. The compound and tread pattern also differ.

Then there's compromises, track day road legals & road legal drag radials.

 

I tell you what though you won't see many Motorsport focused cars with 30 silly little rubber bands, that's a fashion thing that people have become preoccupied with.