How close can pipes be to fiberglass?

[Michael4yah]

How close can exhaust pipes/headers/tail pipes be to a fiberglass body parts before you get problems with the body? When a pic was posted of the up and over tail pipes on the street exhaust I was wondering how close it was to the inner fender but Ive seen lots of side pipes that were close to the body also. Anyone out there have problems with mounting them too close and if so how close was it?

Thanks Michael

[NFLDMNBB]

Mine are very close too, about 5/8". I have always been amazed that I've not seen paint or fiberglass damage

Roger

[FWB]

i see on my car that the pipes where they exit the fender in the cutout are about an inch from the body, with ceramic coating on the pipes, and the paint is slightly bubbled. i have no idea what kind of paint the car was done with, its 2 stage base coat clearcoat.
i think unpainted fiberglass can take more heat then a painted surface. high temp wire loom is made from woven fiberglass coated with some voodoo resin.

[madmaxx]

I had sidepipes as close as 3/16" and never saw any damage to paint or body. 302 sbc ford

[lnfletcher]

Mine were originally about 1/4" but the problem I had was the pipes hit the opening when I ran it hard. Your engine will torque quite a bit and make sure you have the room to clear it. I had to go back and trim more for clearance.

http://lnfletcher.homeip.net/66Cobra/clearance.html

[Trueoo7]

Originally Posted by madmaxx

I had sidepipes as close as 3/16" and never saw any damage to paint or body. 302 sbc ford

I think a big part of the answer lies here. The bigger the displacement, the hotter it will run and the more heat it will give off. For instance I have stainless steel pipes with a 302. They turn a slight tan color that will polish out without too much effort. I've seen 351's and up that will turn the same pipes a scorched blue due to the amount of heat exhausted that won't polish out whatsoever. The bigger the engine the more clearance you may need to give them.

[Rick Parker]

I think it has to do with Exhaust Gas Tempratures. Any of them can be made to run lean an thus hot to varying degrees
if the A/F mixture is incorrect. With under car exhaust, there may be enough surface exposure to the point that much of the heat is dissipated by time it reaches the rear of the car,??? Sort of like touching one of the header tubes and then the tail pipe, there will be a significant difference. Under the hood of mine it was necessary to use some pieces of reflective insulation in the fender liners and under the fenders themselves to protect the fiberglass. My headers give off a lot of heat.

[PANAVIA]

Rick is onto the right idea, the lower the exhaust temps , the closer they can be.

Steve

[mickmate]

Mixture is important but timing even more so I think. I've had exhausts glow red/yellow hot when I left a distributor loose. I keep an inch of space between the body and hot exhaust.