Fat Tyres - to be or not to be....

luke07cupra

Wind the boost up...
Apr 13, 2009
217
0
Leeds
Im running 235's, but thats on 8x18's ET45 and they seem the right size. I probably would not go wider on the standard 7.5 rims than 225's as its the right match.

A quaife is £575 but thats plus the bolt kit and sundries.

For some reason i thought the standards were 8". Duh.

Think i will be sticking to the standard tyre size having read the explantion about grip/friction above. I will be investing in some spacers though, either 8 or 10mm as the car looks too puny from the rear.
 

RobRoy

Active Member
May 14, 2008
47
0
Denmark
Im running 235x35x19, and have slight rubbing when going to fast over bumps and such.

Haven't had rubbing yet when cornering or braking.

Oh, and the guy telling that wider tires doesnt provide more grip? BS. :)
 

RobH

Active Member
Nov 29, 2008
1,547
4
West Yorkshire
Im running 235x35x19, and have slight rubbing when going to fast over bumps and such.

Haven't had rubbing yet when cornering or braking.

Oh, and the guy telling that wider tires doesnt provide more grip? BS. :)

i always wondered why lambos and ferraris have tyres that are as wide as my car
 

depresion

Full Member
Dec 14, 2005
484
0
!!!!!

I'm chasing a ghost by the sounds of it. Wider tyres will do little more than improve the aesthetics a little :(

So from reading that a softer compund is the only way to improve grip as it increases the coefficent of friction over the given contact area?

Is there any other way, other than a fancy diff?

Basicly yes the only two factors that influance grip levels of a tyre are the coeffficent of friction between it and the road and the vertical load acting on it. Wide tyres do tend to be avalable in softer compounds as you would destroy a 145 width tyre in the same compound in a few hundred miles. Unfortunatly the facts of physics gets in the way of the long held perceptions of RobRoy.
 

RobRoy

Active Member
May 14, 2008
47
0
Denmark
Basicly yes the only two factors that influance grip levels of a tyre are the coeffficent of friction between it and the road and the vertical load acting on it. Wide tyres do tend to be avalable in softer compounds as you would destroy a 145 width tyre in the same compound in a few hundred miles. Unfortunatly the facts of physics gets in the way of the long held perceptions of RobRoy.

Surely you have more theoretic knowledge on the subject than I have. I am only from a family with great involvement in racing, and have raced myself for a couple of years now. So perhaps i beat you on the practical knowledge.

I do believe in your theories, but please explain to me why faster laptimes are achieved with the same car, when fitting wider tires?

Wider tires provides more grip, and very importantly also gives more grip for longer durations, as you have also pointed towards. But is is not as onesided as you would like it to be :)
 

Poverty

Guest
On forza 2 when I fitted wider tires to my car, the handling acceleration and braking increased :shrug:

TT-S has 245 width tires too.
 

luke07cupra

Wind the boost up...
Apr 13, 2009
217
0
Leeds
The area where i'd like to improve grip is on acceleration, i'm concerned that excessive wheelspin and wheel hop can damage the driveshafts, I know another member on here as had that problem.

Rob Roy, have you noticed an improvement in grip during acceleration with wider tyres?

Also will lowering the car to reduce rear end squat improve grip during acceleration?
 

RobRoy

Active Member
May 14, 2008
47
0
Denmark
The area where i'd like to improve grip is on acceleration, i'm concerned that excessive wheelspin and wheel hop can damage the driveshafts, I know another member on here as had that problem.

Rob Roy, have you noticed an improvement in grip during acceleration with wider tyres?

Also will lowering the car to reduce rear end squat improve grip during acceleration?

I have experienced improved grip, but I suspect it to be more down to changing tire than the difference in width.

I was, when I was done debating with depresion, gonna make a post saying that i dont believe you will be able to tell a difference from 225 to 235 with street tires. With that said, i do believe there will be a slight noticeable difference going from 225 to 245. But I don't think you can fit tires that wide.

I don't think you need to worry too much about 225, 235 or 245, the most drastic change in grip for you will be in changing compound, ie getting some "sportier" tires like the 888s.

Be aware though, as such semislicks needs a bit of temperature in 'em to work properly. :)
 

luke07cupra

Wind the boost up...
Apr 13, 2009
217
0
Leeds
I have experienced improved grip, but I suspect it to be more down to changing tire than the difference in width.

I was, when I was done debating with depresion, gonna make a post saying that i dont believe you will be able to tell a difference from 225 to 235 with street tires. With that said, i do believe there will be a slight noticeable difference going from 225 to 245. But I don't think you can fit tires that wide.

I don't think you need to worry too much about 225, 235 or 245, the most drastic change in grip for you will be in changing compound, ie getting some "sportier" tires like the 888s.

Be aware though, as such semislicks needs a bit of temperature in 'em to work properly. :)

Yes the R888's are what i was looking at but i think Kumho do some good ones too.
I'm thinking of trying 2 on the front and leaving my Pirrellis on the rear though i'm not sure this is a wise move having different performance tyres from front to back :confused:
 

RobRoy

Active Member
May 14, 2008
47
0
Denmark
Yes the R888's are what i was looking at but i think Kumho do some good ones too.
I'm thinking of trying 2 on the front and leaving my Pirrellis on the rear though i'm not sure this is a wise move having different performance tyres from front to back :confused:

It really won't do anything good for the balance in the car, and you may experience an extremely loose rear end if you drive the front end to the fullest. I would NOT recommend this. All the way, or not at all. The cupra is a pretty good balanced car, and I wouldnt want to mess with it this way.

It doesnt really matter what brand you try to begin with, it will be huge step forward performancewise either way. As long as it is what is considered semi-slicks, it will be a new world to you - but don't get funky in the wet or in the cold. ;)
 

Poverty

Guest
The area where i'd like to improve grip is on acceleration, i'm concerned that excessive wheelspin and wheel hop can damage the driveshafts, I know another member on here as had that problem.

Rob Roy, have you noticed an improvement in grip during acceleration with wider tyres?

Also will lowering the car to reduce rear end squat improve grip during acceleration?

uprate your engine and gearbox mounts mate, its meant to help no end with wheelhop according to jonnyc.
 

luke07cupra

Wind the boost up...
Apr 13, 2009
217
0
Leeds

Poverty

Guest
Just had a look on ther website, interesting, not seen this before. I see they do a LSD too, i need a bottomless pit of money....:blink:

So i take it all this stuff for the mk5 Golf will fit the 1p Cupra?

I know its called Volkswagen Racing but is it genuine VW stuff?

vw racing is to vw what seatsport is to seat. So basically its VW's official racing arm for the uk.

They are the ones that prep the vw race cars. Yeah all the golf stuff will fit the leon.

If you are ever gonna get coilovers they are the ones to set it up for you properly for your requirements but it comes at a price.
 

YIN

Leon cupra Mk2
Oct 6, 2003
904
3
Dudley
www.futuremark.com
vw racing is to vw what seatsport is to seat. So basically its VW's official racing arm for the uk.

They are the ones that prep the vw race cars. Yeah all the golf stuff will fit the leon.

If you are ever gonna get coilovers they are the ones to set it up for you properly for your requirements but it comes at a price.

They have a very high tech suspension set up equipment :wtf:

VWR_Alignment.jpg

VWR_AlignmentSetup.jpg
 

Al

Active Member
Aug 29, 2005
7,331
9
225s scuff on hard corners with Sportlines and ET45 wheels.........
 

Poverty

Guest
They have a very high tech suspension set up equipment :wtf:

VWR_Alignment.jpg

VWR_AlignmentSetup.jpg

its a proven method, teams use it at the racetrack, and thats just alignment, nothing to do with the actual setup of the cars suspension as such.
 
Lecatona HPFP (High-pressure Fuel Pump Upgrades)