I am running Hoosier R6s (235/35/19 F, 315/30/19 R) on GMG 19" rims on my 2010 GT3. Three of the tires will not hold air more than 30-45 minutes. During a recent track session, they would lose 4 pounds every 15 laps. I had a similar problem with R6s mounted to my OEM wheels, but not as severe, as they would not lose air until the car sat overnight. My dealer is investigating the issue, but so far has not been able to determine the cause. Any suggestions as to the potential cause or a potential solution would be greatly appreciated.

 

each tire/wheel needs to be dunked to determine the source of the leak...if not the valve stem then it is likely the beads have not seated properly..sometimes some goop will help seal the tire bead to the wheel and prevent it from leaking...you need a good tire/wheel shop not the dealer...three piece wheels have been known to leak at the seams but these are usually very slow leaks...big leaks like yours are probably either the valve stem or tire bead

 

I recently installed a set as well on my GT2/GT3RS rims (OEM). Two of them are slow leaker's. Although not as bad as yours. Mine lose about 4-6lbs every 24 hours. So in a matter of days they are flat just sitting around in the garage. I was given the same advice, however with a super slow leak dunking them really won't offer up the cause. My source recommend changing the valve stem core. They do it every time they install new tires on their race/track cars. Haven't done it yet, but will be in the next week or two.

Good luck. I'll let you know if I have any success. Are you running TPMS valves or standard? Mine are set up with TPMS

 

talk to hoosier happened to me and they sent me a new tire

 

actually, they can pump them up with a lot of pressure and even a very slow leak will show up in the tank...I had a new rear PS2 on an oem wheel that was loosing only 3 lbs a week and they were able to find it...bead wouldn't seal properly...wheel was fine and I got a new tire

 

Sometimes if the guy who's mounting muscles them too much he could have broken the beads on the tires which causes slow leaks. Since the OP has so many tires that are doing this it could be that they don't know how to mount race tires.

 

Guys, thanks for all the information. I am sending the car to the dealer today for the dunk test and will definitely check the valve stems (TPMS installed). It must be the tire bead or the valve stem, but, as suggested, I wonder if something in the mounting process is causing the problem. My friend, who has an identical setup, has the same problem, but not quite as severe (tires flat by morning). Also, these tires rotate on the rim pretty severely (12 to 15 inches). However, my MPS Cups also rotate on the rim and seem to hold air well. I will post an update when the dunk test is complete. Thanks again for everyone's input.

 

Hoosier beads have given us plenty of issues in the past. Usually it's from the tires twisting on the wheel from torque, or from torn beads from install/dismount. Rarely it's the valve.

Have the tires removed from the rims, thoroughly inspected, and reinstalled carefully with a good install lube. Give the lube time to dry (a day) before going out and pushing the tires. Presuming there isn't any damage to the bead at this point they should be OK. If you need to speak to them, they can be reached at 574-784-3152.

 

Chuck, on the R6's there is a warning not to go over 44psi. I thought I could just put 65-75psi and test it out (dunk) until I saw that warning. Kind of scared me a bit because I have seen more then one person with scarred up face from a tire popping of a rim while inflating (including, bicycle, motorbikes, and auto). Not saying that would happen...but it made me think on the safe side.

Next time I have them on, I am going to mark for the rotation issues as well. I recently noticed some other folks mentioning the same thing. Is that common?

 

Not extremely, but it does happen. Primarily on high torque cars and with tires that don't have the mounting lube dry at the bead yet.

 

I had the same problem on my car with hoosiers it turned out to be leaking from the bead. It didnt matter how many times i had it mounted or by who it always leaked on the inside bead. If you want you can spray soapy water on the tire and bead to see where the leak is.