Tire Sizes?
Burning Brakes
Joined: Jun 2001
Posts: 778
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From: Herndon, VA
A 315mm tire can fit the rear wheel well with the right offset on a 17" wheel. However, the gearing will be thrown off considerably. Although you'll gain more lateral grip, you'll adversely affect the engine's acceleration and reduce the front to rear grip.
Remember, if you put on wider tires but do not change the weight of the car, the contact patch area does not increase - it only changes shape. I.e.: instead of having a contact patch of 24" square with dimensions of 4" long by 6" wide you'll still have a 24" square contact patch area with dimensions of 2" long and 12" wide.
Remember, if you put on wider tires but do not change the weight of the car, the contact patch area does not increase - it only changes shape. I.e.: instead of having a contact patch of 24" square with dimensions of 4" long by 6" wide you'll still have a 24" square contact patch area with dimensions of 2" long and 12" wide.
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From: New Jersey
You will need to do some (alot if the car is lowered) rolling if you do go with 315's.
A really nice setup is 255 in front and 265 in the rear. With the right wheels and offsets it keeps the car nice and balanced without any modification.
A really nice setup is 255 in front and 265 in the rear. With the right wheels and offsets it keeps the car nice and balanced without any modification.
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Burning Brakes
Joined: Oct 2001
Posts: 914
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From: near Louisville
Ed, when I was installing my sound proofing this weekend I noticed new tires are not long off.
Which Pirelli all season tires did you buy? Still happy with them? Did you put on 4 or just 2 in the rear.
Which Pirelli all season tires did you buy? Still happy with them? Did you put on 4 or just 2 in the rear.
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Drifting
Joined: Jun 2001
Posts: 2,446
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From: Florida
John,
Some 928s are over powering the tires they have on their cars and a traditional 265mm tire will not handle the power. I have 275/40/17 tires on my 928 and that is not enough. Granted, my 928 isn't stock and weighs in at less than 3000lbs.
Ed,
Are you saying that wider tires will not give greater grip?
Jim Nowak
Some 928s are over powering the tires they have on their cars and a traditional 265mm tire will not handle the power. I have 275/40/17 tires on my 928 and that is not enough. Granted, my 928 isn't stock and weighs in at less than 3000lbs.
Ed,
Are you saying that wider tires will not give greater grip?
Jim Nowak
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From: New Jersey
Jim,
I agree with some 928's needing 315's. I just disagree about the body work.
My GT has the fender lips rolled by the factory, but I still needed to do a slight flaring with a baseball bat.
Must say the car feels completely different when I run the 275 and 315 track tires vs the stock setup.
I agree with some 928's needing 315's. I just disagree about the body work.
My GT has the fender lips rolled by the factory, but I still needed to do a slight flaring with a baseball bat.
Must say the car feels completely different when I run the 275 and 315 track tires vs the stock setup.
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Joined: Jun 2001
Posts: 213
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From: South Africa
Thanx guys, this is really helping me a lot.
I currently run 17" cup 2's with SO 2's 255x45 rear and 225x50 front and I found the rubber is not near enough to cope with 367din HP, especially when you stomp it when exiting a slow corner, but what's actually frustrating me the most is the lack of front end grip that's limiting corner speed. My suspension is well sorted with custom Billsteins, drop links, coils, lowered, the works and I can clearly feel the suspension is out-handling the tyres.
The Bully is also on a strict diet at the moment. Everything that's not there to make it go faster is coming out - interior is already gutted and the aircon is being removed at the moment.
Three more questions please:
I don't mind slight flaring, so can I go with 315x40(or 35) rears and 255x40 fronts then?
What offsets should I use?
Should I stay with SO 2's or SO 3's or are there better alternatives for track use only?
Thanx guys.
I currently run 17" cup 2's with SO 2's 255x45 rear and 225x50 front and I found the rubber is not near enough to cope with 367din HP, especially when you stomp it when exiting a slow corner, but what's actually frustrating me the most is the lack of front end grip that's limiting corner speed. My suspension is well sorted with custom Billsteins, drop links, coils, lowered, the works and I can clearly feel the suspension is out-handling the tyres.
The Bully is also on a strict diet at the moment. Everything that's not there to make it go faster is coming out - interior is already gutted and the aircon is being removed at the moment.
Three more questions please:
I don't mind slight flaring, so can I go with 315x40(or 35) rears and 255x40 fronts then?
What offsets should I use?
Should I stay with SO 2's or SO 3's or are there better alternatives for track use only?
Thanx guys.
Burning Brakes
Joined: Jun 2001
Posts: 778
Likes: 1
From: Herndon, VA
I am not saying that wider tires do not provide more grip. What I was saying "if the weight of the car and the pressure in the respective tires are kept the same, then the area of the contact patch will be exactly the same". The dimensions will surely be different, but the amount of rubber in contact with the ground will be the same.
There are advantages AND disadvantages to using wider tires. The advantages include more lateral grip. The disadvantages are less braking and acceleration grip, and an increase in the car's overall CD. Also, if the aspect ratio is not correspondingly reduced, then the gearing will be changed adversely. YMMV.
There are advantages AND disadvantages to using wider tires. The advantages include more lateral grip. The disadvantages are less braking and acceleration grip, and an increase in the car's overall CD. Also, if the aspect ratio is not correspondingly reduced, then the gearing will be changed adversely. YMMV.