LSR tires

[desotoman]

Posted on the Gear Grinders website, meeting of March 2, 2006

What?s new in your garage?

Les Leggit: Tire report ? he will be taking 4 tires, having them spun & shaved and then report to the SCTA. Only about 75 cars that need the 30-31 inch tires. Mostly 250 mph plus. Will send them to VA for testing. He is only trying to get a tire for these few cars ? not a 300mph tire, but one for the 200-250. He will try to have a cost for a race ready tire soon. Dunlop and Berkeley in the UK has a 6 ply tire, they are 17inch. There is a 19 x32 which has been run over 400mph.

[Dynoroom]

There is a 19 x32 which has been run over 400mph.

Run or spun?

[desotoman]

Mike, I don't know. That is all that was on their website.
Regards,
Tom Gerardi

[JackD]

The White BBC Turbo full bodied back motored liner that ran the lakes at maybe 275mph over 20 years ago. He ran stock Michelin XVX as I recall it was even recommended he not shave them. That was a surprise. I never heard about a failure. I suspect they would not go the distance at Bonneville.
Spin testing is a fine test, just don't put any weight or HP through them.

[Dave Cox]

I talked with Lester at the GG meeting, the ones he's doing are automobile tires shaved for use to 300 MPH (Dunlops as I recall), that should help the 200-300 cars. I applaud his efforts.

[StraightSix]

Sport car tires are near what is needed already.

Even the tires for the Veyron are unique. They're specially designed by Michelin to handle the stress of driving at 250 mph. The tires need to be sticky like a race car's and able to handle 1.3 G's on the skidpad. However, they also need to last longer than the 70 or so miles of a typical race tire.

Michelin therefore created completely new tires to handle the Veyron's unique requirements. In the rear, the tires are 14.4 inches (36.6 cm) wide. Specifically, the tires measure 245/690 R 520 A front and 365/710 R 540 A rear, where 245 and 365 are the width in millimeters (9.5 and 14.4 inches respectively). The rims are 520 mm and 540 mm in diameter (approximately 20 inches). These tires, in other words, are massive -- the rears are the widest ever produced for a passenger car.

The tires use the Michelin PAX system. Their pressure is monitored automatically, and they can run flat for approximately 125 miles (201 km) at 50 mph (80 kph). According to Michelin, the run-flat detection system "plays an integral role in active safety in PAX System. Its role is to inform you of a loss of pressure, either gradual or sudden." Once warned of an air leak by the PAX system, you can reduce your speed and head toward a tire repair center.

One advantage of the PAX system and its run-flat ability is that it eliminates the need for a spare tire.

[Bob Drury]

On the Leggitt tires, why bother?  The Goodyear tire (28X15) is rated for 300mph at 1750# per tire, and is readily available from Carrol Shelby Enterprises, amongst others.  They run about $400 apiece.  Perhaps Les wants a wider tread for all the power He has ( Goodyear is a 6 Ply with 4.5 inch tread), or he wants to stick with a larger rim.

[JackD]

LSR tires are unique in design in they depend a lot on the pounds per square inch load as opposed to others that are square inches per pound design.
The direction of the contact patch on the salt will often determine what direction you are likely to go best.
They are not the same as other racing demands and "GETAWAY WITH IT" can have a whole new meaning.
The best tires for the deal will be best by original design.

[Bob Drury]

The other thing I didn't bring up on the Leggitt deal is perhaps he has too much power for a quick change.  Incidently, a new Quickchange is about $2500 w/o brakes and with a differential, and almost twice that if you want a 3.00 ring gear(4.11 is standard).  You can gear the 4.11 up to 2.19, but Winters says that will handle about 850-900 h.p. max.  You can cheapen the price by about $900 if you want to run a spool, but I learned a valuable lessson on spools about 50 yards off the starting line, and I don't care to repeat it at 200+ mph.lol.

[desotoman]

Kent Riches, you are famous. Franklin Ratliff just copied your last post and pasted it on the Nitroland website with the title "Live Free Or Die."
Just thought you might like to know.
Regards,
Tom Gerardi

[Dave Cox]

I miss FR (just kidding!)

[JackD]

FR is a Florida state Treasure that comes free if you buy a little of their available Swamp Land.

[desotoman]

Dave Cox, I am with you and applaud Lester for his efforts also. Only good can come out of trying.

Bob Drury, some cars are only set up for 30-32" tires, and 28" tires will just not work. My modified needs 30" tall tires, so it would fit into that category.

Regards,
Tom Gerardi

[Bob Drury]

Tom, I  understand, and The more I think about the Leggitt car on 28's, the more I shudder...............

[k.h.]

Good news from a good source, just got off the phone.  Development continues.  Tire production is still a ways out, but the solution is in the works.