Landracing Forum
Tech Information => Technical Discussion => Topic started by: longshot on May 21, 2012, 09:58:46 PM
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We are building a streamliner and due to the configuration, can only obtain height above the salt by using taller tires. I need tires that are at least 30' in diameter with a speed rating of 186 or faster. I have searched without success. Any suggestions? help! Please reply to my email photio@aol.com.
Thanks.
Walt
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I'd think 30-ft. tires would be hard to come by -- mayhaps you better re-engineer?
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Dunlop makes a 30" & a 32" vintage F-1 tire that are currently being used on severial LSR cars. Doug Robinsons BMR roadster has run 250 mph with the 30" version at El Mirage just last year.
Get your rule book out and look up Rodger Kraus in the ad section, he has them.
Or you could call Mickey Thompson tires.
Remember, have fun
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Dunlop makes a 30" & a 32" vintage F-1 tire that are currently being used on severial LSR cars. Doug Robinsons BMR roadster has run 250 mph with the 30" version at El Mirage just last year.
Get your rule book out and look up Rodger Kraus in the ad section, he has them.
Or you could call Mickey Thompson tires.
Remember, have fun
Dunlop IS making those tires - in 30 INCH diameter (if you really need 30 feet, I don't think any of us can help)... the look to be speed rated for 250 mph (or so)....
Apparently they are not too difficult to obtain.
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Be aware that 30" mickey's are closer to 29" mounted in a static position.............. at least mine are, and the circumfrance confirms it. Bob
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Be aware that 30" mickey's are closer to 29" mounted in a static position.............. at least mine are, and the circumfrance confirms it. Bob
This is correct - as we, last year, discovered to our surprise... the car was RPM'd out at 6mph slower than the calculations said it should be.
Also, Mickey Thompson's 27.5 X15 tires are closer to 26.3" tall....
It is all interesting stuff for new builders....
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Do the 29" Mickeys "grow" at all at higher speeds?
Willi
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Supposidly at "high speeds", but for those of us running 250 or less, I doubt it.
The tires when new have very little (I am told .040 inch) of "tread" rubber and have a ton of cord.
These tires are speed rated at 600 mph and are run usually at 80 to 90 psi.
Incidently, the tires are not for sale, only for lease by Mickey Thompson tires and when I bought mine four years ago they were over $1600 per pair for the 30" X 18".
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Thanks, Bob.
I seem to remember I read somewhere on here that the MTs supposedly grow by half an inch.
Funny, my M&H tires say 29" on the side wall and are close to 30" tall, my Mickeys say 30" on the side wall and are exactly 29" tall . . ..
Willi
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Willi, I think most of the faster streamliners use 31" as a final growth diameter when engineering space required (not including room for salt build up). Bob
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"Dunlop makes a 30" & a 32" vintage F-1 tire that are currently being used on severial LSR cars. Doug Robinsons BMR roadster has run 250 mph with the 30" version at El Mirage just last year."
Be aware of the weight differences between a Formula 1 car (especially the older lower downforce era cars) and a typical Bonneville roadster. Of course, even the long course is far shorter than a F1 race and the track surface is cooler.
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I just realized what I posted earlier in reply #7 doesn't make sense but than again Stainless might argue that nothing else I say or post makes sense.
The bottom line is that to procure M/T land racing tires you must sign a multi page release form absolving M/T Tires (seller) and Specialty Tire of America (McCreary Tire) the actual manufacturer, of any liability from use of the tires and giving them the right to recall the tires at any time.
Hence my referal to the tires as (rented). Bob
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We are building a streamliner and due to the configuration, can only obtain height above the salt by using taller tires. I need tires that are at least 30' in diameter with a speed rating of 186 or faster. I have searched without success. Any suggestions? help! Please reply to my email photio@aol.com.
Thanks.
Walt
You are looking at street tire catalogs, not the SCTA rulebook, or racing tires.
Y rating is 186mph
(Y) rating is 186++ mph.
This has nothing to do with SCTA tire rules. The SCTA currently does not acknowledge the (Y) tire exists. These are what you find on OEM cars that have top speeds in excess of 200mph.
You are allowed to go up to 200mph with VR (very obsolete designation) and ZR tires (in the process of becoming obsolete, it is a meaningless designator today).
A V-rated tire is a 149 mph tire. A ZR-rated tire is a >149 mph tire. Today tires are rated by load and speed:
A 120V mean it will handle a load of 3086lb (120) at 149 mph. There is no such thing as a 120Z, Z is no longer a speed rating. It is a throwback to a time when nobody thought a production car would go past 150mph. There is no VR at all today.
All the 30"+ speed rated tires come off of high performance pickups or SUV's. The largest I could find is a 32.4" Toyo that is 120V. I tested these at 215 mph at Standard Testing Labs, and after 20 minutes at 2200lb load, a small chunk of tread flew off, so I decided not to risk it. HOWEVER, the (Y) rated tire I tested at 215mph and 2200lb (overloaded) exploded before it got up to 215, IIRC, it blew at 210?
So the load rating is actually more important than the speed rating. An overloaded tire will seldom survive even at less than it's rated speed.
SCTA LSR tends to frown on street tires. They tend to be very wide, which can induce a spin. While I found my truck to be MORE stable with treaded wide street tires, my truck is heavier than most entries, usually about 7000lb in LSR mode.
If you want to avoid hassles, go with the 30-18 Mickey Thompson Bonneville's. Those get no questions in tech. Anything else can possibly cause a ruckus.
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DOH!
Before I get anyone's panties in a twist, many tires still say 215/40ZR16. So you WILL see the ZR on the tire. However, that is not the speed rating. The speed rating will be a number + either W, Y, or (Y). That is the true speed rating at full load.
So IF you are looking for street tires, only a V, W, Y, or (Y) model is going to let you go past 150mph.
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Thanks to all. We found a set of Goodyears that are rated for 186 which is all I want my wife to run this year anyway. I was also advised that the Mickey Thompson Bonneville LSR's would satisfy our needs, but at a cost of over $800/tire. Maybe next year for them. In the meantime, I want to thank everyone for their input. And yes, I downsized the whole thing to use 30" tires instead of the 30 foot ones that I initially sought. Hopefully, see everyone on the salt this year. We are bringing two cars if the second one is completed in time.
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Pat, you sent me off in a search to straighten out my confusion after your post on Z ratings. I thought WTF that's not what I know. So after finding some "old" info on the web that was the same as the old info in my head I found the latest:
L 75 mph 120 km/h Off-Road & Light Truck Tires
M 81 mph 130 km/h Temporary Spare Tires
N 87 mph 140km/h
P 93 mph 150 km/h
Q 99 mph 160 km/h Studless & Studdable Winter Tires
R 106 mph 170 km/h H.D. Light Truck Tires
S 112 mph 180 km/h Family Sedans & Vans
T 118 mph 190 km/h Family Sedans & Vans
U 124 mph 200 km/h
H 130 mph 210 km/h Sport Sedans & Coupes
V 149 mph 240 km/h Sport Sedans, Coupes & Sports Cars
W 168 mph 270 km/h Exotic Sports Cars
Y 186 mph 300 km/h Exotic Sports Cars
(99Y) in excess of 186 mph, 300 km/h
when the Y-speed rating indicated in a service description is enclosed in parentheses, such as 285/35ZR19 (99Y), the top speed of the tire has been tested in excess of 186 mph, 300 km/h
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=35&bPostID=post-id-87555290-bf13-4eed-8a0a-f2ecf721438d&
Now there is also a (xxW), when the W-speed rating indicated in a service description is enclosed in parentheses the top speed of the tire has been tested in excess of 168 mph, 270 km/h
http://en.wikipedia.org/wiki/Tire_code
Looks like I will need to keep my towing speed down.
Geo
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I think you can finger it out from this! This info was given to me by MT engineer! Tire growth is linear at other speeds. :cheers:
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Longshot ...you may not want to here this. If your building a streamliner with an existing record you will need the appropiate tires for the existing record not what "your wife is going to drive". If it's under the 186 you probably OK but if it's a liner record at let's say 250 then that's the tire you must have on your car.........Good Luck
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I have a set of the older Mickey Thompson 25x6-15's that are about 24.3" diameter. And at speed grew enough to rub body work with .5-.75" clearance. :(. With that experience in their minds I recall a number of years ago when Don Garlits showed with a liner to do big things, my son and his cousin wandered by and commented to the crew working on the car that the tires were going to rub. In no uncertain terms were told to beat it (in contrast to all other experiences on the salt we have had in 17 trips over 33 years). Did their hearts good when they came back after a pass and found the same crew members cutting body work out from around the tires. :cheers: