How does f/g rear bumper stand up to heat from turbo

[Jim2]

Anyone have first-hand experience with a fiberglass rear bumper on a 930 which gets used on the track?

I'm wondering if the fiberglass will stand up to the heat from the turbo after shutdown. I envision warping etc.

Jim
Solo I 930

[adomakin]

Jim i would use some heat reflecting sheet on the inside of the bumper. it works very well at keeping the bumper from warping and isn't too dear. the stuff ive used in the past had adhesive on one side so was nice and easy to apply-just a wipe with some thinners and stick it on. worked real well on my old 73 RS replica.

[David]

Here's what I did to handle the heat, but I never tried it on the track:

[adomakin]

how you getting on with your build David?

[RarlyL8]

See the bottom picture on Davids' post? That is what I did with mine. The reflective pad works pretty good. You have to be careful with the adhesive you use, on my first DE after installation the adhesive hardened and popped off after about an hour of track time.

It also helps to have a heat sheild in place and a significant air barier between the hot parts and the bumper.

You also might keep cooling in mind when you choose a F/G bumper. The one I have has a large vent above the license plate. It vents a LOT of heat.

[raceman]

these are all great solutions.l had my turbo hot side housing ceramic coated at Swain Tech for about $100.00.l can touch the housing minutes after running the car.

[mmastro]

ThermoTec has some really good products for heat management.
http://www.thermotec.com/

A few previous threads on this subject:

Rear bumper heat with muffler shield removed 84 Carerra?
Newbie Question: Regarding Exhaust Heat

Jim2 wrote: "Anyone have first-hand experience with a fiberglass rear bumper on a 930 which gets used on the track?"

Heat's not a problem if your muffler stays bolted to your turbo....fiberglass looks like this when it's not:

[David]

Originally posted by adomakin
how you getting on with your build David?

The end is in sight. I should have all the mechanical work complete this week. Then I'll be installing all the additional sensors for the EFI and boost control and then it's time for wiring. I posting some pics a couple weeks ago here and on Rennlist.

[Jim2]

Adomakin, 125 shifter, Rarly, mmastro et all, thanks for the input. It looks like there are several solutions here. I happen to know someone who has some of the foil backed ceramic mat, so this will be my first choice.

Regarding the f/g bumper, it looks like I'm shopping! The weight diet on the very rear of the car should be worth the effort of changing to the f/g bumper.

Jim

[Jim2]

All, I bought a Rennspeed fiberglass rear bumper. Fit was excellent and it met my usual picky expectations. I also had a set of 964 tail lights so I installed them at the same time. I used ceramic thermal mat for heat barrier and bonded it on with silicone. Worked really well. Per Rarly's advice I also added heat vents a la mmastro.

The color is not matched to the car yet.

Shortly after the bumper was done I decided on a larger turbo which I just finished installing. The total weight savings from the bumper, 964 tail lights, and altered turbo plumbing is 56lbs.

Next... I just picked up efi manifolds from another member. Sliding down the steep, steep slippery slope!

Jim

[Asjac]

Off topic, what is different about the 964 lights? No outer black/chrome edge? Thanks!

[Install425]

I made an aluminum plate to cover the whole exhaust.

[adomakin]

Jim, whats that turbo? is it an ITS? also, the hard line coming from the top of the oil catch tank-is that a support or something else? surely its not the return?

[Jim2]

Off topic, what is different about the 964 lights? No outer black/chrome edge? Thanks!

The 964 tail lights and housings are made entirely from plastic. The conventional 911 tail lights use a cast metal housing which I suspect was intended to endure potentional rock damage from the rear tires since the housing are exposed. Shaved about 6 lbs off.

Adomakin, the turbo is a custom spec Turbonetics assembly. Oil reservoir is constructed very similar to the stock unit with the left line drawing from the bottom of the reservoir even thought the line enters on the top. There is also a separate vent line to the valve cover which comes off the the top right side of the reservoir. It's difficult to see.

Jim