another wheel and tyre question,

[josewick]

i have been looking for some new wheels for my car but can you tell me why the NSX runs a combo of 15/16 or 16/17??

Can I use same diameter front and back but different tyre ratio to maintain the rolling radius? that way it is easier to source in 2nd hand market.

i.e. stock rim uses 225-45-16 F and 255-40-17 rear... if I found a full set of 17s and use 225-40-17 (same roling raius as the 16s) and maintain 225-40-17 at the back..?

Also what offet do i need for the rims?? normally I am worried about not clearing front caliper.

thanks

[ctrlaltdelboy]

there is no problem in what you propose - oem wheels on 2002+ models are 17" front and rear.

+38 to +42 is pretty much where you want to be, but you should check out the wheel & tyre section at prime for recommendations on the specific diameter & width you intend to go for as well as tyre choice - there are some experts in this area that hang out there who will give you the best advice on offset

[josewick]

cheers darren.#


at least that way i stand a better chance finding what I want at a reasonable price..

Cheers

[ctrlaltdelboy]

you can go for whatever tyre widths that you want/your rims will handle (with the right offset)

the only reason to maintain factory ratios is for the TCS, but I never use that anyway.

factory is 215/45/16 & 245/40/17 by the way

[markc]

Josewick,

I can understand where you're coming from by wanting to buy a set of 4 wheels/tyres of the same size, you'll save a fair amount of money over 2 "odd" pairs, but I'm not sure it's a good idea.

Another thing to bear in mind is that the front and rear wheel centre bores are differant, 70.1mm and 64.1mm respectively. So you'll need to get a set of 4 wheels with the larger centre bore and fit a "spigot ring" on the rear hubs. (I think that's the correct way round)

Almost all mid/rear engined have larger width rear tyres than front ones. Quite whether that's a for real roadholding/handling reason reasons or 'cos they've all always been like that is probably open to debate.

Most mid/rear engined cars are a) powerful and b) rear wheel drive, these things both demand grip/traction at the rear. They also tend to have a rearward weight bias meaning that lateral force (at least transfer) is likely to be greater over the rear wheels.

No doubt a lot of these factors could be engineered out through suspension design BUT the fact is they weren't for the NSX.

Theoretically, putting on substancially wider front tyres while retaining standard width rears, and leaving aside the potential TCS issue, should make the car more oversteery. Not necessarily a bad thing BUT it may just make it unpredictable!

If you're using the car as a dedicated trackday weapon (like Darren) you'd probably want to experiment with tyre sizes but for a road car I'd stick with the standard front to rear width ratio (dont' worry about diameter ratio).

Cheers

Mark

[josewick]

mark

just that I am trying to get my head round it really..

Surely I didn't know about the centre size being different from front and rear.

But the way that appeals to me first was that, if I change to a different set of wheels but maintaing the correct ratio in diameter or even width (there about), I should get any problem, theoretically, I can even run a tiny 10" rim with massive profile to maintain the "rolling radius" (I know that is a bit to an extreme but you know what I mean.)

I will have to look at a lot of others and may be check out prime and see what they use over there...

Cheers

[Kevin]

It's not offset that determines caliper clearance. As it depends on how the offset is produced. The distance between the hub face and the inside of the spokes, is the caliper clearance.

The sizes are different front to rear, to keep the weight down. The car didn't need big wheels in the front, so it didn't get them. Modern styling probably dictates more than anything else that the current NSX has 17' front and rear.

Anything wider than 225 on the front, with the standard wheels will rub the bodywork. In fact 225 with standard wheels touch the inner body (mind did). So a smaller offset in this case will allow a wider tyre, as a smaller offset will move the rim further out, away from the centre of the car.

I would think that all aftermarket wheels are made with a large centre bore, and you use a ring to resize the bore to match the centre hub of the car.

Also the front NSX sizes are an uncommon size, and its hard to find a wide range of tyres to suit. If I were you, I'd check out tyres as well as wheels. Make sure the tyres you want are available in the size of wheel you're thinking of. Especially applies for track tyres.