I didn't get any overheating at Laguna Seca this Miatas @ MRLS weekend, but the foil tape on top of the radiator ripped. I wonder if it was due to vibration or due to air pressure:

 

mine mostly did the same thing, and in the spots where it didnt rip, the adhesive let go eventually.

 

Yup, that's what happened to mine. I have a big hole cut in my bumper above the stock mouth though, and the mouth is sealed to the bottom portion of the radiator. I've just stopped sealing it there.

 

I put foam weatherstrip on the seam, then the foil tape on top of that. Seems to hold up better.

 

Would it be crazy to just layer the tape perpendicular? Similar to composites layering in different axis's.

Do your normal long one across the length, then do a bunch of smaller pieces perpendicular on top of it, and then if you wanted finish with a 3rd layer the same as the first.

Either one would probably let you know what it is. I doubt the air pressure would burst through any of that, but the radiator pulling/shaking around might.

 

The tape doesnt have a different amount of strength in either direction. Its really not meant for this purpose. I have different high temp tape that withstood the stress much better because it had a weave like duct tape but the adhesive didnt last long on the radiator.

 

I used some industrial HVAC tape used for duct work. It seemed to do better than the home depot foil tape but it still ripped after 3ish months... I'm sure 100+mph doesn't help it either.

 

I think the solution is either foam, or to put an ABS plastic or thin metal flap there and then add tape. There cant seriously be THAT much movement there.

 

As that area is sealed better, the pressure increases. Radiator is mounted pretty solidly to essentially the same thing the tape is stuck to, and the rubber isolators don't have much flex unless they are really worn out. I'd put my money on that being pressure related.

-Ryan

 

DEI foil has fiberglass reinforcement and a high temp adhesive. It might work better than standard foil tape.

 

DEI foil is what had the failing adhesive for me.

 

I have some Pegasus foil and some DEI foil here. I can compare them and see if the adhesive is better on the pegasus foil.

 

I do the same. I think its half-inch thick weather strip from Home Depot. Make sure its good, I have tried about 2-3 brands and only one of them sticks well. I put it between the radiator and the mount area, then tape over it. Seems to last a while for me also.

 

I layered the Harbor Freight foil tape over some upholstery foam that was squeezed into the gap and it typically held. Changing to a different radiator helped as well. Must have been some combination of pressure and movement.

 

I tape somme shower pan liner and it held alot more then just foil tape that ripped after 2 races.

 

abs plastic or thin aluminum butted up to it works best. I did layers of foil and it lasted 2-3 months usually. not bad since it only takes a minute or two to put fresh tape on. Important though since all that air that's pushing the tape off is much better used when forced through the radiator.

 

I have had good luck using good black duct tape in the past.

 

My strip of Gorilla tape has held up well so far through 5 track days.