Fiberglass Bumper & Heat

[juanbenae]

Speaking of fiberglass bumpers>>> http://66.236.61.177/showthread.php?t=357511

I just recently installed one of Dave @ TreMotorsports rear bumpers that I was most please with fit & finish on but now after a track day have experienced MAJOR heat transfer. So much so that the 1st couple run sessions upon returning to the paddock you could actually smell fiberglass. It does not make actual contact with the earlier type stock banana muffler but is with in a half an inch or so of the muffler on the entire bottom edge. The thing got so hot that you could not touch the surface of it bare handed for 15-20 minutes after my return to the paddock. I have seen no actual smoke or evidence of burning of the FG to this point.

With standard road driving I did not experience the what I will call super heating of the unit like I did at the track Fridee. The bunper remains unpainted with the gel-coat finish. A couple questions for the masses, and Dave you have an email asking much the same from earlier this morning.

*Will this continued heating and cooling of the bumper make fiberglass brittle over time? I am killing this bumper softly (like the song) and slowly?

*If this is of no harm to the fiberglass with this at a minimum kill the gel finish?

*I have seen an insulating fabic material that looks like aluminum foil with some sort of pillow look that I imagine contains a layer of some sort of insulating fabric. Does anyone know where to obtain this stuff that I could possibly line the bumper with? Will this material with stand the close contact with the muffler?

* I did not do the RUF bumper for the very reason I do not want to drill holes in this new bumper to get more air moving around it. This is a "part time" track car and the holes are less than desirable for my application, but might consider such if it is the only way to not kill the bumper. I remove the lic plate for track days and am considering drilling some hole behind the plate mounting area that would remain covered during road use.

Will this heat be no problem for fiberglass and should I let er run?

TIA, and this is on a 911 to keep this thread from being moved to a regional or OT forum.

T$

[ttweed]

I use an aluminized heat barrier cloth on mine from Pegasus:
http://www.pegasusautoracing.com/productselection.asp?Product=1832

I glued it in place with a "high-heat" silicone adhesive. The main problem I have had from the muffler heating the glass bumper is the paint/gel-coat checking/cracking on the outside and lifting the coating. In extreme cases, the structural integrity of the FRP could be compromised.

[Wavey]

http://66.236.61.177/showthread.php?t=228674&highlight=fiberglass+bumper+exhaust+heat

[juanbenae]

i have ordered some of the sticky backed heat shield from airport spruce, and drilled some holes for heat escape behind the lic plate. as i said the plate comes off fer track duty so i will apply the heat stuff and see what it accomplishes.

thannks

[jester911]

I made a simple heat shield from aluminum sheet metal that was thin enough to bend. Before I put the bumper on I attached it so it has a little air space between it and the muffler. After several track weekends in the heat it has had no ill effects.

[Jack Olsen]

I put some on and the adhesive gave up. Anyone have a specific adhesive they like?

[NY65912]

We "rolled" a piece of sheetmetal around a large pipe for an arc, attached a few screws and ta-da a heat shield.

My rear bumper is warm after a 20 min flogging in 90 deg heat.

[juanbenae]

http://www.hrpworld.com/index.cfm?form_prod_id=879,587_4249&action=product

there is this ... http://www.hrpworld.com/index.cfm?form_prod_id=879,587_4249&action=product

i may use some of that plumber's tape stuff, the steel strap the use for tying pipe off in walls, its got holes every inch or so. i will adhere the heatshield to the bumper and then bend it to fit the bumper's inside shape and screw it with a few sheet metal screws through the hidden spots on bumper. so i am thinking.

T$

[911pcars]

Originally Posted by NY65912

We "rolled" a piece of sheetmetal around a large pipe for an arc, attached a few screws and ta-da a heat shield.

My rear bumper is warm after a 20 min flogging in 90 deg heat.

Yep,
I clamped some flat al. bar to the muffler to afix some sheet metal screws.





That works.

Sherwood

[RWebb]

heat shield cloth from Jerry Woods - not my install





why won't the server take my pics directly???