Streching Tires... The truth behind them?

[Reckless Hero]

it depends on how stiff the sidewalls are, but depending on wheel size and shape it can some times be easy, my 215's slid right into place with just normal air pressure

[_PG_]

fyi 14 inch wheels will barely clear rear brakes on a 240. To get them to clear the fronts you'll need to do away with your brake calipers.

[CrazyHawaiian]

I ran the 225/50/17's on 17x9.5" rears this past weekend and I loved it. Car was sliding great. Next up are some 235/45/17's in the rear.

[mikep]

I realize this is an old thread, but I want to add something.

When the rim is wider than normal, you get camber gain when the tread moves sideways. The outer sidewall gets taller in side load, while the inner gets shorter. This is due to the angled sidewalls.
When the bead is pinched in, there is camber loss.

So on cars that need more negative camber but are lacking adjustment room, a stretched tire can help.

I run a 195-60-14 Azenis on a 7" Celica GT wheel when I autocross my 83 Corolla. I am limited to -1 deg. camber and 4.5 degrees caster. I ran narrower wheels and the temps were higher on the outer edge. The wider wheels got the temps even across the face.
I have not drifted this car yet. I got the springs and suspension balanced, and now it needs some power. That is this month's project.

[malcolm]

I didn't realize that. Excellent post. *gives two thumbs up*



(however, you can't have it stretched too much, or the tire won't flex enough to give that camber gain... What the people here are talking about are stretching the tire to the point where it won't flex the sidewalls, to prevent the sidewalls from absorbing any potential energy, and thus preventing them from releasing that energy when the tire loses grip)

[Whisky]

Using stretched tires to circumvent the rules is a great idea! I kinda like that.

I noticed that you are using a 60 series tire, so your method makes sense. Most of the "drift style" fans are running very small sidewalls stretched to extreme angles, which may add some response, but it is absolutely detrimental to grip.

I remember some months back reading an article in GRM where a guy ran larger wheels in the front of his car than the rear to aid in turn-in response (it was a blue C5 if I remember correctly). I thought that was fairly clever too. But don't expect function to come before form to most of the people who think stretched tires are cool, as most of them get into drifting thru anime and Option videos, not karting or racing.

[Ziptyed]

i ran 15" by 6 out back, and 16" by 7 in front does that count.

[free motion]

I just mounted 195/60/14 Azenis sport tires on my SSRs and it works great! It barely looks stretched, even on the 7.5s, but I love the look they have. The Azenis Sports are awesome tires although treadwear is only 200.

[Whisky]

i ran 15" by 6 out back, and 16" by 7 in front does that count.

Thats what I did when I was first learning to drift. Ran my 5Zigens up front and my stock steelies in the rear. It made it easy to get the tail out and it made it easy to carry long drifts because even a stock KA can burn down 195s. As you get better you'll find you want more control, so bigger rear tires actually become helpful.

The 'Vette guy was running big meaty tires all the way around, just a larger front wheel so he could run the same diameter but with less front sidewall for better response.

[Buddyworm]

I've read this entire post through and I still can't wrap my mind around one thing. How do you determine the smallest tire that can be fit on a given wheel size? For instance, what's the smallest you can go on the stock rims on a 91-94 240SX (I know they're 16s but I don't know the width.)

B-Wurm

[NeveR]

You gotta do some basic math.

205/60/R15 is the stock tire size for the 240sx (89-90 Teardrops).

The width is 6" if i'm correct.

So 205 is in millimetres and 60 (for the sidewall) means 60% of 205 gives you the sidewall in millimetres: 123mm.

Therefore, if you were to stretch the stock tires to be COMPLETELY flat, you'd have 328mm of contact patch, or approx 12" of contact.

Obviously, this is impossible as the tire could not be stretched completely flat.

Get the picture? Just work it out.

So lets go down a few sizes 195/50/R15

195 + (50% or 97.5mm) = 292.5mm of contact patch. Which is 11" at FULL STRETCH (which is obviously impossible.)

So you could fit 195s with VERY VERY minimal stretch. Or you could go even lower and have more stretch.


I hope that made sence.

[Buddyworm]

Thanks. Helped out quite a bit.

B-Wurm

[GRiDRaceTech]

You don't stretch on stock wheels. If you "need" stretch on stock wheels, you are not good enough and SHOULD NOT be drifting.

[malcolm]

You don't stretch on stock wheels. If you "need" stretch on stock wheels, you are not good enough and SHOULD NOT be drifting.

HAHAHAHA!!!! I love it. so true.

your stock wheels will be about 8" wide... that's roughly 200 mm wide. to have a stretched tire, you would need something like a 160. Good luck trying to find something that narrow, with 16" diameter.

[NeveR]

Hey now,

I do not in any way, shape, or form, advocate the stretching of tires on stock wheels.

And, as mentioned above, it'll be quite difficult to find a tire thin enough to be stretched.

I was just explaining how to calculate it.