17'' wheels for trackdays

[trev4]

I have got the chance of a set of 17'' wheels for trackdays and I want to keep my standard wheels for road use so my question is will I need to adjust the ride height every time I change wheels or could I get away with just swapping them over.

[ianwayne]

If you fit tyres that have the same diameter, the ride height won't be affected. For example, 225/45 x 17 on the rear instead of 225/50 x 16 is only 0.5% difference (3mm more. Easily taken up in tyre wear). There are many websites that'll calculate it for you. Here's one:

http://www.kouki.co.uk/utilities/visual-tyre-size-...

Changing the ride height because you're going on a trackday is another issue! Others can advise on that, mine is not adjustable.

[s p a c e m a n]

They will most likely fit without rubbing, the issue will be that the standard wheels have a different circumference front to back so you will be nose high with the same size wheels all around. Think that you could possibly alleviate this by using different size tyres front to back on the 17 inch wheels. If I remember correctly my 17 inch wheels with low profile tyres on were about the same size as the standard front wheel and tyre, so you'd just need to find a decent 17 inch tyre with a decent sized side wall on it.... Or you could just adjust the suspension

[phazed]

Trev. I set my car up , correct ride height for my track wheels.

The front road tyres are the same diameter but the rear track tyres are larger.

This gives the correct slightly nose down attitude on track and a level look on road tyres which I can live with.

If we are honest, the car will never be affected by a slight difference in nose down ride on the road.

Of course, if you obtain the same tyre diameter then you won't have a problem.

My road rears are 255-40-17
Track rears are 265-35-18

Hence the difference.

[Classic Chim]

As mentioned if you keep the rolling circumference similar front to rear it should be ok.

The problem with that is you’ll have a low profile front tyre which is a bummer on the road but not such a bad thing for track tyres

[trev4]

Thanks for the advice guys looks like a will be getting a set of 17'' wheels in the not to distant future.
I have been looking at Nankang AR-1 tyres which they do in my widths 225 front 255 rear although I would have to have a 45 on the front and a 40 on the back which is not ideal but they seem to have good reviews.

[SILICONEKID 345HP 12.03]

Why would ride hight make much difference ? The wishbones are in the same place and angle .

[phazed]

Yes, the ride height would change as my track wheels are larger in diameter and therefore lifting the rear of the car up in the air and pointing the nose down, (in an exaggerated way).

[SILICONEKID 345HP 12.03]

SILICONEKID 345HP 12.03 said:

Why would ride hight make much difference ? The wishbones are in the same place and angle .

My track set are

215/40/17
235/45/14

[SILICONEKID 345HP 12.03]

[quote=SILICONEKID 345HP 12.03]

My track set are

215/40/17
235/45/17..

Federal 595rsr and dirt cheap ..
Very good grip to.

[trev4]

Must admit I am tempted to give the Federals a try, they are half the price of the others I have been looking at.

[phazed]

I am running federals at the moment only because they were half price. They take more warming up but when warm are almost as good as the triple eights.

[trev4]

I wonder as I'm only going to use them on the track if a coat of tyre softerner would bring them in quicker.

[SILICONEKID 345HP 12.03]

[quote=SILICONEKID 345HP 12.03]Im not even sure you need massive wide tyres , nothing worse than tyres catching especialy when these track tyres cone alot wider than road tyres even when labled the same size .



Theres a few guys out there only run 205 225 toyo r1rs and they stick like glue ..


Alot of the above tyres will catch because the body can sit slightly out and catch on the near side rear so if you dont want to modify the arches you might be disappointed .
.
Anthony will be here soon .

[trev4]

SILICONEKID 345HP 12.03]ILICONEKID 345HP 12.03 said:

Im not even sure you need massive wide tyres , nothing worse than tyres catching especialy when these track tyres cone alot wider than road tyres even when labled the same size .



Theres a few guys out there only run 205 225 toyo r1rs and they stick like glue ..


Alot of the above tyres will catch because the body can sit slightly out and catch on the near side rear so if you dont want to modify the arches you might be disappointed .
.
Anthony will be here soon .

I was concerned about tyres rubbing that's one of the reasons I asked the question.

I'm afraid there is no comparison on grip between r1rs and class b track tyres, I am hoping to go to the comparison track at Snetterton in a couple of weeks time if you are going you are welcome to try my 888s to judge the difference.

[QBee]

Trev, your maths above is wrong. 225/45 and 255/40 will give the same diameter as each other, front and rear. You need 255/45 instead to give the 25mm TVR rake.

I am very wary of going too wide with rear tyres due to rubbing the rears. My first set of R888s rubbed and were 235/40 18. Raising the ride height cured it, but when I put the tyres on someone else’s car, he was laying smoke all round the track. Your call entirely. 245/45 would be safer, or 215/45 front and 235/45 rear.

[SILICONEKID 345HP 12.03]

245/45/17 are tall , alot taller than standard . Best thing to do is jack it up and drop the shock absorber , then you can check if it catches.

[trev4]

225 front and 255 rear works well with no rubbing on my 16" track wheels but basically I can only buy 888s at £700 plus fitting or more expensive tyres which I find hard to justify.
Maybe a slightly narrower tyre would not be such an issue but I really wouldn't like to compromise on the grip I have become used to.
Basically I want 888s but don't want to pay for them.

[Classic Chim]

trev4 said:

225 front and 255 rear works well with no rubbing on my 16" track wheels but basically I can only buy 888s at £700 plus fitting or more expensive tyres which I find hard to justify.
Maybe a slightly narrower tyre would not be such an issue but I really wouldn't like to compromise on the grip I have become used to.
Basically I want 888s but don't want to pay for them.

Ive been trying to work out where this is going
Hilarious as if your going for track wheels and tyres you have one or two options..
1 the best grip available
2 not the best grip available but affordable and in the case of RSR last ages.

If these are for the best days out I’d go for best grip then look after them until they’ve hardened a bit, two or three good runs getting then hot but not scuffing them at all is the way I believe.
They then last a long time even soft compound tyres,, if you don’t slide to much that is.

Get the best and go faster,,,,, in for a penny
I’m good at spending others money !!!

[QBee]

trev4 said:

225 front and 255 rear works well with no rubbing on my 16" track wheels but basically I can only buy 888s at £700 plus fitting or more expensive tyres which I find hard to justify.
Maybe a slightly narrower tyre would not be such an issue but I really wouldn't like to compromise on the grip I have become used to.
Basically I want 888s but don't want to pay for them.

Are you doing Snetterton in a couple of weeks time? If you are, go out on my R888Rs and see what you think. They are 215/45 17 all round. Shock horror.....but the grip is superb.