Mike in CO

Loctite website says Loctite Red (271) only holds to 500 deg F.
http://www.loctiteproducts.com/p/10/...er-Red-271.htm
I found a couple of other high strength, high temp Red compounds, but all seemed to release around 450-500 deg F.

LVDell

I'm thinking I should have any issues now that the car is retired to street duty and won't see the brake temps the track saw. I'd have to go back over my notes, but I could have sworn that the PFC01 saw temps in excess of 1200F. That could very well have broken down the thread locker. When I removed the studs the red thread locker was just a crumbly powder and flake.

997gt3north

New to this tread - but I had a similar experience 10 years ago when a tracked a heavy, 500hp S4. I used studs - but after a while I just learned that I had to every time check and tighten each stud as on every wheel change 50% of them were loose. I came to the conclusion this is just what studs do and with my 997gt3 I never switched over to them. After reading this thread, and thinking back, I would now guess for certain it was the heat. My 3700# S4 had 500 wheel HP so the heat it generated in the brake zone was very extreme (and thus one of the many reasons why I bought a GT3). I had Stoptechs on the car to help the situation - but you know when the painted calipers are changing color - heat is an issue. I will never track a heavy car again.

As an aside, but somewhat related, I remember sharing a bay at Watkins with a 996 turbo owner that was doing 2:15s and all he talked about was braking issues - how he was using bigger better calipers, etc, etc but was still having issues.

I vote for heat being the issue. And if so, is there any cooling solution you could do as it may also help pad wear.

LVDell

I have the 6 pot brakes and 350mm rotors with cup ducts so I can't get much better with the cooling without getting custom ducting done.

But asking a car that is almost 3500#, a 210# driver, a tank of gas, to stop from triple digit speeds to school zone speeds repeatedly, it's a recipe for disaster. Just look at all the brake issues NASCAR cars have on the tracks that are demanding on brakes.......pedal to the floor, tire bead rupture, etc..

I'm almost certain now thinking about all the variables, that brake temp is what led to this.

Time to buy a lighter car

AllanJ

Don't go too light. Given a choice between a Miata or a 911 turbo with loose studs, I'd weld those studs in place!

LVDell

But the entire miata costs less than a new gearbox in the Turbo!

AllanJ

Shift smoother.

Am I helping?

Bill Lehman

I'm running a Cayman S with DBA rotors and PFC pads. The rotors have heat sensitive markings which indicate I'm hitting 550 C or 1022 F. The car has a stock motor so I'm not hitting speeds that a TT or GT3 will. This is exceeding the Loc-Tite limits. I second the cleaning of the threads before using Loctite. They used to sell a "primer" in a spray can. It appeared to be a fast solvent like acetone or MEK.

LVDell

Thanks Bill for the input

Allan, I shift slow and deliberate so I don't have to buy a gearbox. But when making the comparison, it brings it back to reality when I compare an entire track car to a single item like a gearbox on the Turbo. I've already rebuilt one gearbox in the GT3 and that is a bill I don't want to see again

NJ-GT

On my 997 GT3 RS I tested two different brands of studs, both of them I got from CDOC. One brand was race-studs, the other one I don't remember but I still have them, CDOC doesn't sell them anymore.

When I installed the longer ones (100mm long) I tried to torque them to 150 ft-lbs (50% more than the torque used by the stock lug bolts). Well, they kept going inside the hub, eating the unthreaded section of the stud, so I took them out and decided not to use them.

So, I then put the race-studs 80mm ones, they stopped bolting in as I reached the unthreaded section of theese studs, even at 150 ft-lbs of torque, so unbolted, put Red loctite, and back in. I used the 150 ft-lbs of torque all around.

Why did I use a much higher torque rate to bolt the stud to the hub? well, common sense, I want the lug nuts to come loose when removing my wheels, not the the whole stud/nut assembly. I stopped using the impact wrench to get my lug nuts loose, instead using an old torque wrench with a 1/2 counter-clockwise turn at all bolts, then lift, then use cordless drill to remove the nuts.

Loctite Red 2620 has 650 degrees F resistance. Floating rotors have a much colder center on track days, and the wheel carriers (hubs) are even colder than the brake rotors centers.

You won't see 1,000 degrees on a hub, that would kill the wheel bearings in a few days.

LVDell

Thanks for the input Rad.

I'm confused on the high torque value of the stud only. Since there is nothing resisting against it (i.e., the wheel and nut), I'm confuse how you could get that value (or why).

Burger

I'm less confused, more concerned, lol.

NJ-GT

I learned this removing and installing headers in my older cars. More often than not loosening the headers nut would give me a stud/nut combo rather than just a nut. The nut and stud tend to seize with time, so I used to torque the engine heads studs (that hold the headers) to a torque value 50% higher than used by the nut. Wheels studs follow a similar process.

How to do it? very easy.

Place a first lug nut on the stud, but place it looking backward, I mean the hex head points to the hub, the round end points to you, get it 40mm or more onto the stud. Then use a 2nd lug nut, once the two of them make contact (round end of both lug nuts make contact), you can apply all the torque you need to tighten the stud to the wheel carrier. When finished, un-tighten the two nuts in opposite direction, and remove them from the stud one at a time.

SH || NC

The stud install torque is 15-20 ft#. Are you saying you used 150 ft# to install the stud into the hub?

IPguy

Definitely don't do this with head studs! Don't ask me how I know, really don't.