The one thing that stops me trying to max out the IROC is the worry of a tire (sorry tyre ) blowing on the motorway at 80 mph +. Basically if that happens you are fubared. I have heard that 'curbing' your tire is a factor but sometimes it can just be manufacturers defects Any one have any advice of any brands to avoid?

Thanks

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'86 Iroc ZZ4
Best Run 13.8 @ 100mph
I told you to blow the bloody doors off!
The British Firebird/Camaro Site

 

There are several things. First of all is the manufactures speed rating on the tire. It should be a letter H,S,T,V,Z something like that. I don't know exactly what the speeds are that correspond to the letters, but there are websites and people here that do.

The other thing is tire pressure. If it's low it will build a lot of heat due to the larger contact patch. Low pressure could also cause the sidewall to contact the road and it could blow that way. Too high and normal heat buildup causes very high pressure.

Tires blow for two reasons.

1.) Too much pressure causes the sidewall to either blow off the bead, or blow out by the tread.

2.) Too fast and the centrifugal force causes the tread to separate from the sidewall.

I guess there's actually three, debris will kill tires at high speed easy. Most tires are stong enough to withstand high speed at very short intervals, but not sustained speed. Just remember that these are not racecars and a 140 mph crash is not so easy to walk away from much less live through.

Hope this helps.

 

Thanks, so basically buying the right tire and then maintaining them properly.

When you say walking away from 140mph crash it reminded me of a video over here of a Mecedes on the Autobahn doing about 150 and he loses it, rolls about 30 times and slides on his roof for about 1/2 a mile... all is then painfully quiet for about 15secs.. then you see the guy opening the door! The video is so good they used it for an ad over here for a short time... The safety of German cars.

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'86 Iroc ZZ4
Best Run 13.8 @ 100mph
I told you to blow the bloody doors off!
The British Firebird/Camaro Site

 

Overheating blows out tires, and is probably most commonly the result of overloading, UNDERinflation, or both. Some tires are more susceptible to this than others - consider all the recent flak about Firestone SUV tires.

My strong recommendation is to purchase tires that are UTQG rated "A" for temperature.

And here's the table of letters vs speed ratings.

Speed Rating Symbol
RATING SPEED RATING
SYMBOL (km/h) (mph)
B 50 31
C 50 37
D 55 40
E 70 43
F 80 50
G 90 56
J 100 62
K 110 68
L 120 75
M 130 81
N 140 87
P 150 93
Q 160 99
R 170 106
S 180 112
T 190 118
U 200 124
H 210 130
V 240 150
W 270 169
Y 300 188

ZR Over 240 Over 150


Norm

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1979 Malibu w/some cornering tweaks and a few other interesting things

 

I have seen that video of the bimmer rolling. He lived for one reason: BMW convertibles have a roll bar which is hidden behind the seats. There is a sensor inside the car which senses the angle of the car to the pavement. if the car tips more than 40* (something like 40*) then the rollbar very quickly flips up. Anyways, another thing which can blow a tire is reversing the rotation. Never switch tires from opposite sides of the car. Front to back is alright, but right to left or vice versa is bad. The reason being is after a while of driving, the steel belts actually get twisted in that direction. Reverse them and they will try to twist the other way and literally rip the tire apart. Finally, if you really want tires for high speed, there are 2 tires which are rated for 200+ mph. The Michelin MXXX and the Pirelli P-Zero. I read a magazine article about a guy with a camaro which would do 206mph and he ran the michelins, I believe.

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1983 Firebird
TH700R4 Auto
Small Block 400
LG4 ECM, Intake, Carb, Distributor, etc.
Soon to be non-computer.
Clarion Head Unit 45X4
2 Pioneer 400W 12" Subs
Third Gen Performance
"A four cylinder is half an engine."
"Ponies can run, but birds can fly..."