tyres

[Josh_Cohen]

what is the smallest profile i can put on standard 14 inch glt wheels

[stealthstylz]

Apparantley you can get 175/40R14s but never seen em ever.

Matt

[germ]

well ive got 185 55 14's on ofter market wheels

but i believe the 14's had 185's? i think 185 60 14

the differnce in looks is quite large my 55's look cool and it definatly accelerates faster than with its stock 175 70 13



Cheers
will

[d3k4y0]

how are you working that out?
Smaller wheels will give a falsely high reading on the speedo anyway, so it may just be an illusion.

If it was as straightforward to put smaller wheels on a car to make it accelerate faster then all 1/4 mile cars would be running on 12"s surely?

I know the drifters are all putting smaller wheels on, but that's to increase the torque at the wheels to make it break traction easier isn't it?

I find it hard to believe the negligable increase in torque and the decrease in unsprung mass from lower profile tires is going to have any real effect on acceleration

[germ]

i am simply making a statment that for me on my 14" wheels with 55's

instead of 60's its made a differnce in accel its not any massive differnce but it makes a differnce

any way there is only 2% differnce on the speedo with these tyres as we had it measured

also have you put a 60 next to a 55?

i was surprised by the differance

any way its very very little but noticable

the handerling too is affected from 175 70 13 to 185 55 14

the car feels much surer and not twichy like it was on 175's

now for drag racers and such there are differnt reasons for that wheel and tyre sizes.

the wheel and tyre size... well tyre size changes GEARING!! not torque

small profile = better accel big = better top speed ofcouse the speedo wont read this unless its been calibrated too.


cheers
will

[Chris_C]

Man has a point dude, rolling radius of the wheel changes gearing, and has as much of an effect as changing the final drive.

Tis why fake will be going out on a 1.4 diff and 12's when I get round to it!

[d3k4y0]

There's no need to be so defensive Will.

All I suggested was that I personally can't see the gain being noticable, and yes, you're right the drifters do use smaller wheels to change the gear ratio, but if you change the gear ratio, you will change both the torque and the moment (both will decrease, and I've been out in the sun too long!) but make the wheels easier to spin up.
I am more than willing to accept that you will see an improvement in acceleration on silly little 12" low profiles, but I just didn't think the gain would be noticble unless you lose a reasonable amount from your rolling radius.

The handling improvement is something I can definately understand, and it's probably a combination of a larger contact patch (from wider tires) and stiffer sidewall.

[Bilbo]

get some 12" imp/mini rims
carlos fandanggo's

[pettaw]

gearing changes torque, but don't forget it also decreases the amount of speed per unit revolution of tyre/engine/whatever.

So sure the revs go up faster, but do you actually make more progress on the road? You have to strike a balance between not making the gearing too long so that the engine never gets into its torque band and not too short so you're forever running out of gears.

Chris, good luck cornering on 12s Unless you're going low aspect ratio in which case Kar's gonna look very 'interesting'

[Chris_C]

It'll be Fake, not Kar don't worry, it'll happen around the same time as my 16ver conversion and the cage buckets and harnesses

[Nick C]

In which case remember you don't want low-aspect tyres on a rally car - you need a fair bit of sidewall to absorb the impacts from stones/potholes etc or you'll just bend the rims. 55 or 60 minimum (technically I think the blue book says 60, but I've never seen anyone check...)

[Chris_C]

S'ok, to get any benefit it'd have to be low profiles (and it'd be fine until you came to a white ) Main prob is 12's not going over the brakes I reckon... but I havn't offered up yet.

[stealthstylz]

Im fitting 185/55 R13s onto mine, which are about 40mm shorter than the 175/65 R14s that are on at the minute. Will definetley make a noticeable difference to the acceleration.

Matt

[Frits]

That size was on my 114 GTI, there are not much (street) tires for. In dutch I only could get Semperit and Toyo.

hmm. Toyo at the front, semperit at the back

[stealthstylz]

Ive got pirellis and then a spare pair of goodyears hehe

Matt