Tires

[bbarn]

Greetings. Durring our runs on the salt at the WF, we noticed the tires on the rear of our lakester we were showing a cord on the diagonal of the tire (just one per tire). We checked around and got some good advice that this is common as it is the butt connection of the tire cap. I know the guy that told us about them was giving us good advice that the tires were still good. He showed us the same "issue" on his streamliner tires.

My question is, how do you know when a tire that has no tread to measure is in need of re-tirement (pun intended)? I don't think that Lincolns head on a penny is going to be of any use here.

[SPARKY]

When it goes beyond concern and SCARES you to WITS END!!!!!!!!! 

[robfrey]

When it goes beyond concern and SCARES you to WITS END!!!!!!!!! 

Can you be a little more specific?

[Milwaukee Midget]

I'm a scardy-cat on this stuff, so my thought is, if in doubt, change 'em out.  There's enough to worry about to risk your neck on tires you question.  Yeah, there seems to be a lot of old rubber on the salt, but in the end, you're the one riding on 'em.

[Bob Drury]

  Rob, I cannot speak for the current (2007-up) Mickey's, but in 2005 I borrowed a earlier set of the same size which had several fifty cent size bare (cord showing) spots and several more diagonal cords showing.
  I used the time tested method of cleaning out the cord areas and applying black RTV silicone to those areas.
  I made one pass with my 4300# Studebaker with a 700 horsepower Early OLds engine in it.
  When I stopped to pick up my timing slip the person handing the ticket asked me incredulously if I had just run 214 (I think) on those tires.  I got out and looked at what appeared to be sofa cushions that had been attacked by a pit bull.
  My suggestion to you is that you call M/T tires, ask thier advice, and use your best judgement.
  A lot of people run these tires in a simillar condition, but I doubt that many of them would pay to buy those same tires.
  The fact that none of the users own the tires, and the fact that you signed a multi-page disclaimer to rent those same tires, releasing the tire manufacturer and the tire leasor of any responsibility should have made you aware that its every man for himself when using a experimental tire ( as is printed in raised letters near the rim on the sidewall.
  You have chosen to be a part of a pretty safe sport, but as you raise the speed, you raise the potential risk of failure of any and all parts of your race car......  the advice you need to follow is that of your own head and no one else's.............Bob

[robfrey]

We bought the car with those tires from Dave Haller.
I had noticed that we had cord showing on one of the tires. Dave only had one or two runs on the tire and I believe his as there were still casing nubs sticking up not far from the showing cord. He called Mickey Thomson and they said this was normal. It appears that there is a little overlap of the cords and since there is so little rubber cast onto the tire, this is where it will wear through first.
If cords showing on these tires are a problem, I don't know what we can do as we can't afford to put a new set on every two runs.

[SPARKY]

Rob,  I have had my tires inspected after each season- by some one I respect as one of the more knowledgeable LSR tire guys.  I watch him CLOSELY, as well asks questions when he inspects my tires---whether it is the sidewall splits and crack of the GOODYEARS or the diagonals of the MTs---what he is looking for is cord seperation and breaks---

I run a PG or an AT and no TQ converted with a STOCK valve body--to keep from spinning my tires needlessly---you have a much larger issue wit tire spin than I do---my experience is you can hook up around 2500 lbs of TE on a good track  ---some of the more succesful racers STAGE their power---as the mechanical advantage goes down the power goes up.

[Bob Drury]

  Rob, unfortunatly, the M/T tires have very little rubber on them even when new. Keep in mind they are designed to go 600 mph so the tire mass has to be kept to a minimum.  Also keep it in mind that what kills tires is spinning them.  With that in mind, you need to find that delicate spot where that is held to a minimum (ala traction control).
  The time proven method is to either add weight or downforce, or lift on the throttle when the tach speeds up (a tough thing to judge).
  As Sparky mentioned, aero plays a large part, especially in your type of vehicle.
  If it was my car, I would watch for signs of tire spin, which would probably show up as a very rough surface, and then try out adding more weight, although a external wing would be better.
  I would also try to determine which end of the cord is lifting and mount the tires to reverse this if neccessary.  M/T tires are not directional, however the Goodyear LSR Tires are.
  If at all possible don't trailer the car on the race tires.
  When you get home, drop the pressure to about thirty psi, clean them off and use a UV protectant spray like 303 aeromotive protectant (available at most parts stores near the tire cleaners).  Put the tires in a cool dark spot and cover them up.  They DO NOT like light, including flourescent lights.
  Do not leave them ON THE CAR......... nothing good will happen. 
  Another option would be to run the 28 inch Mickeys, which are a lot cheaper, and are rated at 300.  Seth Hammond and many others have gone over 300 using them.            Bob
 

[racergeo]

   I'm under the impression that Goodyear is going to enter the LSR market with a new 450mph tire. I'll bet it has a little more rubber on it and address all the prblems just spoke of. I've spoken to Dave Farwell, the Goodyear engineer in charge of this and the dragrace tires, and they won't come out with something unless its right.

[Bob Drury]

  Boy oh boy, that would be good news to the 85% of us that need a larger or wider tire than the GoodYear 28's but don't need a 600 mph tire.  Sign me up George!!!

[SPARKY]

Bob,   unfortunately I have heard they MAY  be MUCH more expensive than there present tires.

[robfrey]

We were 80 psi in the tire at WF. Is that too much?
I know we spun the tires but not a whole lot until the last run but the cord was already showing by then.
Been keeping the tires in the temp and light controlled environment and certainly not transporting with them on.
We can probably get a few more licensing passes on these current tires then it will be time for a new pair.
C'mon Goodyear!

[racergeo]

 Rob, do a search on this subject from back before MT made their current tire and you will find that Al Teague and others ran on some tires that many thought to be very scary. Your tires may have a lot of use left in them. Aren't they 6 ply? Run em down till there 4. Heh heh

[McRat]

I'm still a FNG, but here's what I know:

On the M/T's, even when brand new, you can see where the cord will show first.  There is only 1mm rubber on top of the cord to seal it.  Or so I was I told when I asked M/T.  Kinda wish they would have made the second cord red, so when you see red, you discard.  This is the way some aircraft tires are.  I run either the 26" or the 30" on the front only at 90psi with about 1700lb loading.

Dunlop Racing tires are 32" dia on 18's, and have lots of tread on the them.  IMO, they are very tractible in the dirt.  Krause Racing sells them.  I run them on the rear only at 75psi.  I've only run 197 on them, but at 2000lb loading per tire.  I've been told they are good to 250mph.

[SPARKY]

Bob, that is going to be my criteria---when I start seeing several  cord seperation in the 2 cords I will relagate them to lower lisc runs.