Stretched Tyres For Track Days

[WARLORD]

i have a track day coming up soon and i have 18x10s front and back on a r33 gtst now what would be the go with stretched tyres ill be only doing 4 to 5 laps at a time one which is a warm up and one which is a cool down (don't ask) so two laps at full pace,what do you guys think about these sizes.

F 245/40

R 245/40

F 245/35

R 245/35

F 255/35

R 255/35

F 255/35

R 265/35

as for brand any ideas they must be UTQG rating higher than 100 and um (wtfit)

thanks.

[nisskid]

depends on the sidewall, but those sizes u put up are not much of a stretch, well within safe.

with 309kw (going by ur sig) id be going for a staggered sizes, give a bit more meat on the rear to help get the power down.

for a 18x10 id be going 245/40 or 255/40 front, 265/35 or 275/35 rear. depends on the availability and price etc

[WARLORD]

depends on the sidewall, but those sizes u put up are not much of a stretch, well within safe.

with 309kw (going by ur sig) id be going for a staggered sizes, give a bit more meat on the rear to help get the power down.

for a 18x10 id be going 245/40 or 255/40 front, 265/35 or 275/35 rear. depends on the availability and price etc

my sponsor is buying the tread,and as for 309kw i hope to be up to 330kw by that day with new products.

one quick thing i can't remember why 40 in front and 35 in back i did that with my 17 45f and 40 back but i can't think why i did it...lol

i was thinking 35 in the front to make sure i clear everything under load in corners.

[nisskid]

the 35 at the rear is because its wider, since the profile is a aspect ratio, the 35 on the 265 will have a similar size sidewall height to a 245 with a 40 profile.

[WARLORD]

the 35 at the rear is because its wider, since the profile is a aspect ratio, the 35 on the 265 will have a similar size sidewall height to a 245 with a 40 profile.

what about if i go for more clearance in the front with 255/35 and what 266/35 or 275/35 or 30

thanks nisskid

[Al]

i have a track day coming up soon and i have 18x10s front and back on a r33 gtst

**Sorry, a little off topic**

Have you modified you guards to fit such rims?

Any pics?

[HEKT1K]

he has... if you don't mind warlord:

[WARLORD]

hey al

they are a little but if all goes well i have another sponsor that is going to pump and flare the guards when its done ill post pics

[WARLORD]

no body knows if stretched tires are bad or good for track days,sure some smart person would know something factual.

[nisskid]

no body knows if stretched tires are bad or good for track days,sure some smart person would know something factual.

the sizes u posted arent stretched, well not much at least, they will be fine, albeit not as grippy as something wider. not exactly sure what response ur after? wider will have more traction yes.

[Potenza]

no body knows if stretched tires are bad or good for track days,sure some smart person would know something factual.

Tyres are designed/engineered to fit a specific rim/rims. If you fit tyres to a rim that is outside that specific range you can:

* Reduce grip through contact patch distortion

* Risk either - Beads unseating from bead seat

* Damaging Bead and or Sidewall because it is being distorted and was designed to be used in this way.

My advice don't do it.

[nisskid]

Tyres are designed/engineered to fit a specific rim/rims. If you fit tyres to a rim that is outside that specific range you can:

* Reduce grip through contact patch distortion

* Risk either - Beads unseating from bead seat

* Damaging Bead and or Sidewall because it is being distorted and was designed to be used in this way.

My advice don't do it.

lol at those 2 points. how many cases have u heard of that happening? its just tyre shops/manufacturers saving their arse. the biggest issue ull have with stretched tyres (im talking properly stretched tyres, like <205's on 10" rims) the tyre can roll off the bead.

[Potenza]

lol at those 2 points. how many cases have u heard of that happening? its just tyre shops/manufacturers saving their arse. the biggest issue ull have with stretched tyres (im talking properly stretched tyres, like <205's on 10" rims) the tyre can roll off the bead.

Lol at everybodys relaxed attitudes towards "strecthing" tyres. I see damage from missuse and misapplication with tyres everyday - everyone is an expert. What would the engineers and the independent tyre & rim standard engineer/members know. The good old "she'll be right attitude"

While your at it why not leave the wheel nuts undone.

Edited January 12, 2009 by Potenza

[nisskid]

any documented cases?

because ive never heard of any, i'm sure they are around, but the fact i havnt seen one tells me they arent very common.

a 245 on a 10" is only one size under the reccomended, do u really think tyre manufacturers would reccomend a 255 on a 10" rim if they knew the size under could potentially cause a failure, resulting is pretty massive compensation?

they keep a massive safety margin because they can, theres no need to reccomend a 245 on a 10", it doesnt make any significant impact on sales, but it gives them a massive cushion for any complaints.

[WARLORD]

now this is progress !!!!

nisskid & Potenza this is what response im looking for,thanks.

if you guys have any more info please keep going if not thanks again.

[bnr#@]

I ran 225 40 r 17's on 9" rims on my GTR around barbagallo on my first outing there, had no issues. Stretching the tire gives you a bit more response as there is less sidewall flex but you could have better grip with a wider tire...

Tires were Bridgestone potenza's re050 was bouncing the ripple strips all day with them

[Ronin 09]

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.

[Snowman]

yep.

We run 245's on our 9.5" rims and 265's on our 10.5" rims for best results. So on a 10" maybe a 255 would be the way to go but it's generally not a common size in which case I'd tend towards the 265's before the 245's.

[WARLORD]

yep.

We run 245's on our 9.5" rims and 265's on our 10.5" rims for best results. So on a 10" maybe a 255 would be the way to go but it's generally not a common size in which case I'd tend towards the 265's before the 245's.

what size 255/35 or 255/40.

thanks.

[MrStabby]

For a baseline to work within ask the tyre vendor, or hopefully just check their website. They publish what rim sizes are suitable for which tyre. Even if the sizes are identical, different tyre models can sometimes accept slightly different rim widths.