Stretched Tyres For Track Days

[nisskid]

how many V8 supercars do you see with fully sick stretched rear tyres onto 11ty billion inch width rear rims?

how many rally cars do you see with stretched tyres?

how many F1 cars do you see with stretched tyres?

If it was any performance benefit these boys would be all over it before you'd even heard of it.

if we're talking about performance, then the right size spec tyre (near vertical sidewalls, if a little leant over toward to tread) will perform the best.

you don't see lambos, fezzas, porkers coming from factory with a 225 on a 10 inch rim, for a reason.

definately, but that has already been covered, no one is debating that. we are talking about whether its safe.

i know personally i have stretched over the years for drift, whether it be due to tyre availability or simply looking for tight, predicable sidewalls, never had an issue, but u will lose grip.

saying that, it depends on the tyre, if all ur running is cheap street tyres, then sometimes some stretch is better, over the years ive sometimes had street tyres on the front which have soft sidewalls, and found that stretching them a bit (225 on 9" kind of stretch) actually helped as it stopped the sidewalls from flopping around. saying that if ur running proper performance tyres with strong sidewalls, there is no need to stretch, and you will lose grip.

[kingscorp]

Dont stretch the tyres!

Get the right tyre for the rim. I will be using a 255 on my 9" rims on my Silvia racecar. So with 10's I would say you will need the 265's all round.

My RX7 racecar runs 225's on a 7" rim and that works fine.

You need some sidewall flex in the tyres, if you stretch the tyres you will find the tyres will tuck under and roll on the edges. The slip angles will also be reduced making hard to balance the car on the edge of grip and slide

Ashly

[aDrew_C]

I've got 235/40 on my front 18x8.5's and 255's on my 18x9.5's. It works really well for me, only a slight undersize on both, which is not considered stretch.

I'd recommend 265/35's for you, or you could go 275/35's if you don't have guard issues.

[WARLORD]

definately, but that has already been covered, no one is debating that. we are talking about whether its safe.

i know personally i have stretched over the years for drift, whether it be due to tyre availability or simply looking for tight, predicable sidewalls, never had an issue, but u will lose grip.

saying that, it depends on the tyre, if all ur running is cheap street tyres, then sometimes some stretch is better, over the years ive sometimes had street tyres on the front which have soft sidewalls, and found that stretching them a bit (225 on 9" kind of stretch) actually helped as it stopped the sidewalls from flopping around. saying that if ur running proper performance tyres with strong sidewalls, there is no need to stretch, and you will lose grip.

thanks nisskid for staying on the subject whether its safe or not.

and thanks for the input guys im thinking of 255/35 all round or 255/35 f 265/35 for a bit more rear traction cos my 17/255/40 are just no good.also are staged size tires better for track or not as ive noticed a lot of front and rear being the same size on FR cars

[NZM.031]

i had 255/30 on my 9.5" rims on my 33 gtst and they were great.. stretched 235/35s for drift and it made a huge difference to the grip levels... the back end became all sorts of slippery.... for a track day... i say dont stretch the tyres.

[nisskid]

i had 255/30 on my 9.5" rims on my 33 gtst and they were great.. stretched 235/35s for drift and it made a huge difference to the grip levels... the back end became all sorts of slippery.... for a track day... i say dont stretch the tyres.

hardly a fair comparison though, firstly i doubt they were the same brand and model tyre (might have been tho), 2ndly ur reducing the size by 20mm each size, of course ur going to have less grip, that doesnt mean the stretch was responsible for lower grip.

[NZM.031]

yes you're right, its not a fair comparo... what i should have said was.. drifting was much easier and more controllable with the stretched 235s as it felt much stiffer and more responsive in the back end.. that was without spinning the wheels until after the apex where power was starting to be applied and yes, the 235s had much less grip which made power oversteer much easier..

[nisskid]

yeh a stretched tyre is much more tight, responsive and easy to control, hence why a lot of drifters that arent high level who get good tyres given to them (with strong sidewalls etc) use stretch with cheaper tyres.

as far as grip though, a 235 on a 8.5" and a 235 on a 10" would be a better comparison for stretch vs non-stretch.

[RT33]

I have 235/40/18 on the rears (9.5" rim). Used it at Wakefield and there was no problems. Never actually heard of anyone losing a tire though over stretching.

[runnin4life]

how many V8 supercars do you see with fully sick stretched rear tyres onto 11ty billion inch width rear rims?

how many rally cars do you see with stretched tyres?

how many F1 cars do you see with stretched tyres?

If it was any performance benefit these boys would be all over it before you'd even heard of it.

if we're talking about performance, then the right size spec tyre (near vertical sidewalls, if a little leant over toward to tread) will perform the best.

you don't see lambos, fezzas, porkers coming from factory with a 225 on a 10 inch rim, for a reason.

its simple more width, more grip (with exceptions) and from what I understand v8 super cars, f1 and WRC etc run tyres with a stiffer side wall compared to a regular car or sport(road) tyre

Just out of interest in terms of the actual structure of a tyre, how does a semi slick compare to a normal road tyre, do they have stiffer walls, or are they the same, just diffrent compound and tread pattern??

cheers

elliot

[kingscorp]

The R comps have a much stiffer side wall, hence they are crap for drag racing but great for cornering