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Nail in Racing Tire


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I would like to get some advise from the experts. I have a GT3 that now has a nail in the drivers' side rear tire. A local, experienced, PCA shop said that they could plug the tire and I would be good for DEs. While I am in the lower groups I was still a little concerned about taking a "plugged" tire on the track. Any thoughts?

Thanks,

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When I was roadracing motorcycles, I plugged a front tire and continued to use it without hesitation. Speeds were slightly over 150 on the fastest part of the track and I knew from previous experience running with a totally flat front that as long as speeds were over 60-70 mph that the centrifugal force would make the tire fairly stable. Speeds below 60 would make the steering heavy and much below that, the front would really start to squirm and it could get un-nerving. Being in tune to the bikes handling, I knew I could detect a slight loss in air pressure before anything drastic happened so I did let it bother me.

Go with your gut, if it worries you get rid of it as you will focus on it and it will keep you from giving it your all. If you feel ok with it, worst case, may be sloppy handling if you lost air. A car is a lot easier to handle with a flat than a motorcycle.

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If the nail is near the center of the tread, I wouldn't hesitate to repair the tire and continue to run it on the track. However, I would make sure that it is done the "right" way. The tire should be removed from the wheel, the inside should be inspected for damage and a "stem patch" should be used which both plugs the hole and reseals the inside of the tire. I did this after I picked up a screw in a track tire and then ran the tire to the cords without a problem.

I would like to get some advise from the experts. I have a GT3 that now has a nail in the drivers' side rear tire. A local, experienced, PCA shop said that they could plug the tire and I would be good for DEs. While I am in the lower groups I was still a little concerned about taking a "plugged" tire on the track. Any thoughts?

Thanks,

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When I was roadracing motorcycles, I plugged a front tire and continued to use it without hesitation. Speeds were slightly over 150 on the fastest part of the track and I knew from previous experience running with a totally flat front that as long as speeds were over 60-70 mph that the centrifugal force would make the tire fairly stable. Speeds below 60 would make the steering heavy and much below that, the front would really start to squirm and it could get un-nerving. Being in tune to the bikes handling, I knew I could detect a slight loss in air pressure before anything drastic happened so I did let it bother me.

Go with your gut, if it worries you get rid of it as you will focus on it and it will keep you from giving it your all. If you feel ok with it, worst case, may be sloppy handling if you lost air. A car is a lot easier to handle with a flat than a motorcycle.

We'll mark this as something NOT TO DO.

I am sure glad that I wasn't on the track with you when you were doing this. I roadraced in CMRA which was our club racing and you may have been in WERA. If you had the 'feel' of a tire going down than you should of had the 'feel' that it wasn't the right way to run. Wow.

Plugging a performance tire is good ONLY if you do it to get home and if you are in a bind. If you plan on running the car at any higher speeds then please do us all a favor and replace it. DE's and a plugged tire seem like a not so bright thing to combine.

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johnthomas...that is what I am going to do.

I was surprised when a PCA approved shop talked about plugging the tire. I thought maybe because I was in the lower run groups that it would be good. But I am not going to "play" with it. Thanks for the comments and ideas. subject closed.Regards.

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  • 2 months later...

As it has already been pointed out, it really depends on where the nail is, and how 'clean' the entry of the nail is. The 'best' you can hope for (other than not getting a nail in the first place!) is that the nail is in the middle of the tyre carcass and the nail is in the middle of a tread block. This is where there is least lateral movement in the tyre.

I was at the 'Ring a couple weeks ago, and late on a Saturday I noticed a nail in my left rear causing a very slow leak. Local garages were out of 295 tyres, so I brought the car to one of the local race garages. They plugged the tyre and confirmed that the tyre would be perfectly fine for continued use on road and track. Upon review of the tyre plugging kit, it was fully TUV approved and did not carry any warnings or stipulations that the tyre should be limited in use.

Later that night I drove down to Hockenheim at speed ;) and attended a trackday the following day. Trackside temp was 28deg C, and the tarmac was HOT. The plugged tyre performed faultlessly all day. The tyres were heavily marbled at the end of the day from the heat and melted rubber, and you could not see where the plug was. As the tyre heats up, the plug actually remelts into the surrounding rubber.

I would not hesitate to plug a tyre - but it really depends on where the nail is. The nail in my tyre was 'ideally' located so it seemed a good candidate to be plugged.

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  • 3 weeks later...

This is an amazingly contentious subject. I asked a friend here who owns not one but TWO cup cars and here was his explanation:

There are two ways to fix the nail:

1) The gooey rope looking thing that's shoved in from the outside of the tire. This is fine for street and DE events. The tire will be fine but it will lose it's "Z" rating at that point.

2) Removing the tire from the wheel and patching it from the inside. The tire will retain it's "Z" rating and will pass tech inspection for a race.

That said, it's completely up to you if you're willing to run a tire this way. I know some club racers that replace the tire at the smallest nail. I know others that'll run them patched just as hard. I haven't seen any solid data that indicates a tire patched from the inside was any more likely to fail.

-Charles

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