Landracing Forum
Tech Information => Technical Discussion => Topic started by: Rex Schimmer on February 10, 2009, 12:52:02 PM
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Looking thru the lates Coker catalog and they are offering replicas of the 50-60s Firestone Indy car tire. The catalog says "an exact copy" so I called and asked what their speed rating was and Doug at Coker said that they would not put any type of speed rating on them for obvious reasons but that the tires are "exact" copies of the Firestone Indy tires with more modern materials. That being said if you look at the "Old Bonneville pictures" thread you will see lots of cars with these tires. Wonder what would need to be done to get the SCTA to approve?
Rex
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Rex What sizes do they come in ?
Thanks Willie Buchta
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I've been told the old Indy 18" start chunking at about 230. Maybe if these were shaved they might last at higher speeds.
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Willie, The catalog says 760-16, which are 29.75 inch dia and 800-18 which are 31.25 dia.
Tony,
I would agree that if you shaved them they might be good 200 mph tires.
Rex
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These tires have been discussed by the tech people. As far as I know the tires will not be approved for competition. You could ask the question at:
rulebookinfo@scta-bni.org
The Coker catelogs used to say "for display only" or some such thing.
DW
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I called a couple of times. Talked to some guy who was supposed to know what was up. When I told him that the real things had been used on a car that went 400 (Al) he told me that any car running at 400 would fly. It was not possable. The next guy I spoke to said they were made in the same molds but were 4 ply. I told him that the original tires were 8 or 10 I thought. He said they must have been truck tires. He did believe the tires were limited to 130 max and said he would look into it and get back to me. Not yet.
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Coker tires are made for vintage tin. I wouldn't use any of their tires over 150.
"Exact copy" Just like the "real" Rolex you can buy for $15. They definitely mean exact copy of the looks not exact copy of the construction.
They are not in the racing business despite the "racing" tires they list in the catalog.
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Are there any approved LSR tires larger than 30"?
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Are there any approved LSR tires larger than 30"?
several.... look at a couple of the big rigs using large aircraft tires. Read a little about the Phoenix, there is a thread with links in General Chat
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Are there any approved LSR tires larger than 30"?
several.... look at a couple of the big rigs using large aircraft tires. Read a little about the Phoenix, there is a thread with links in General Chat
I believe I'd have to run the aircraft tires through the approval process. At $1000 each, and about the same for getting custom 2-piece wheels made to hold them plus another thousand for testing, it is way beyond my resources. It's still very interesting, and they come in a huge assortment of different sizes.
My fantasy tire would be 34" tall on a 16-18" rim, but that means aircraft only.
My guess is I will be running the Mickey Thompson 30" tires and just have to change the axles to get enough gear. A 32"+ tire will give me 200mph capability without putting lightweight axles under it. Nice thing about our trucks, is that the 11.5" ring and pinion is pretty much indestructible, but guys who have played with 12-bolts, 9" Fords, and quick changes have destroyed them in diesel applications.
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Several years ago Les Liggett ran tall aircraft tires on his lakester at El Mirage. Results were not worth the effort. I don't remember if he tried them on the salt. Maybe Dan can remember.
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Several years ago Les Liggett ran tall aircraft tires on his lakester at El Mirage. Results were not worth the effort. I don't remember if he tried them on the salt. Maybe Dan can remember.
Do you remember if he had mechanical problems with the tires? We are looking to go 225mph maximum.
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McRat
If you did a lighter weight rear axle just for Bonneville I don't believe you will have a problem with the smaller gears. Being traction limited on the salt and having gobbs of torque, I'm guessing that will be your problem. Just blowing off the tires.
Now, an interesting idea might be DRW with LSR 28" GY tires In my time on the salt, I have not seen this done, but ? Who knows.
Rick
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McRat
If you did a lighter weight rear axle just for Bonneville I don't believe you will have a problem with the smaller gears. Being traction limited on the salt and having gobbs of torque, I'm guessing that will be your problem. Just blowing off the tires.
Now, an interesting idea might be DRW with LSR 28" GY tires In my time on the salt, I have not seen this done, but ? Who knows.
Rick
Yes, we might be forced to swap axles. Goodyear only makes 15" wheel tires, which won't fit our axles. Even 16" is very tight.
It would be cool to run a Dually setup just for the Blingus Maximus factor. :-D
But the "interesting" part of our truck I think is that it ran Sled-pulling, Drag-racing, Towing, and LSR-racing with very little (any?) changes other than tires. So if I can keep it in Swiss Army Knife configuration, it would be cool.
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When Banks set the FIA record in the Dodge-Cummins truck he blew the whole back off the quick change. Left a bunch of scrap on the course. We had a long clean up.
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When Banks set the FIA record in the Dodge-Cummins truck he blew the whole back off the quick change. Left a bunch of scrap on the course. We had a long clean up.
That's what I heard. The Banks truck was pushing less power than I am if I understand it correctly, so a quick-change isn't going in our truck. Our problem is that diesels make their power at very low rpm's, and it's brutal on drivetrain parts. A 2500hp alcohol car rear axle won't survive in a 900hp diesel truck.
In 30 years of racing, I've shut down a track 3 times for cleanup, all in the last 7 years: A Corvette rear blew pieces 50' out the back on a 7,200rpm launch at Carlsbad (first time I think that track actually had any traction), lifted a cylinder head at Calspeedway at the 1000' marker, and grenaded a transfer case at Calspeedway. Probably 5,000? passes on bikes, cars, and trucks. Normally I like to destroy stuff where nobody can see. :-D Stealth technology. Casper's last pass at Bonneville did about $22,000 worth of carnage, but held together.
Anyhow, I'm going to run the short course so it's easier to clean. :evil:
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Dunlop 550-18's and 750-18's have been sucsessfully used for the last few years over 200 mph. They are not true LSR tires and if used in "moderation" may be good for many applications. I do not know the load limits and I have only been 216 on unshaven 750's with a 3500# roadster. I believe the 550's may have been run 240 on other rioadsters. I have heard they are getting hard to get.........Good Luck JD.
IMO the Coker 31's look great on a 29-32 high boy................
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Here is a link for the Dunlaps.
http://www.rogerkraustires.com/Dunlop/Vintage.shtml
Roger also carry the Blockley tires at least one Roadster runs or ran.
Tom G.
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My fantasy tire would be 34" tall on a 16-18" rim, but that means aircraft only.
McRat,
Does you class allow Overdrive transmissions like a Gear Vendor? If so here is a quote from their website:
GEAR VENDORS provides overdrive product to racing cars and trucks up to 2000hp and trucks towing heavy RV's up to 25,000lbs gcvw.
Might be an option for the salt. Just a thought.
Tom G.
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Thanks! Yeah, I've looked at the gear vendors unit and it's certainly an option. I do know another LSR diesel pickup that had trouble with their's but I don't have specifics. I believe they had to "piggy-back" two units together, and it didn't hold. Team FASS?
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McRat,
What ever you do for a rear gear you need to size it on it torque rating and not horse power. You make lots of torque to make the hp you do at the relative low rpms and that is why quick changes will not take your engine. They are rated at 800 hp but that is at 8000 rpm input not 4000. Have you looked at what the tallest gear is for a Dana 60?
Rex
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Thanks! Yeah, I've looked at the gear vendors unit and it's certainly an option. I do know another LSR diesel pickup that had trouble with their's but I don't have specifics. I believe they had to "piggy-back" two units together, and it didn't hold. Team FASS?
Gear Vendor is a great company but it would not hold up to the 222 cars torque.
JL222
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McRat,
What ever you do for a rear gear you need to size it on it torque rating and not horse power. You make lots of torque to make the hp you do at the relative low rpms and that is why quick changes will not take your engine. They are rated at 800 hp but that is at 8000 rpm input not 4000. Have you looked at what the tallest gear is for a Dana 60?
Rex
Haven't checked the Dana 60 yet. Thanks!
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rat....
be carefull....yes its no secret we don't have traction, but thats not the problem... if you ever heard a real hard b-ville pass like Teage or Burkland you'll hear a whurr, whurr, whurr as each drive wheel fights for traction... kinda like sponson walking...loosing traction is not the problem... when it hooks back up is when it blows shit up.... repeated jarring and pounding is unavoidable. so my advise to all those who build light 'cuz we "don't have traction" buy 2 cuz your gonna need it!
Kent
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rat....
be carefull....yes its no secret we don't have traction, but thats not the problem... if you ever heard a real hard b-ville pass like Teage or Burkland you'll hear a whurr, whurr, whurr as each drive wheel fights for traction... kinda like sponson walking...loosing traction is not the problem... when it hooks back up is when it blows Subaru up.... repeated jarring and pounding is unavoidable. so my advise to all those who build light 'cuz we "don't have traction" buy 2 cuz your gonna need it!
Kent
That's what I'm thinking. One problem with my truck is the power comes on all at once, and if you feather the pedal or the engine unloads, it drops boost suddenly. It's a side effect of big turbo boost that's hard to tune out of it without losing high RPM ability. If at all possible, I want to keep the factory axle as it's proven to withstand huge shock loading.
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Kent
Whenever I here that sound its from a solid suspension car and the jackhammering causes a lot of drivetrain problems.
JL222