kgorman

Wasn't this a picture of a C4 lightweight?

Jasko

J richard - I have seen that photo before but I couldn't figure how the central weight of the bumper is supported under the middle reflector. The two black suspension bars are new and are not on the stock cars. It makes sense that those two suspension pieces would support the weight of the bumper cover at the bottom, but what keeps the the bumper from sagging at top under the rear reflector? On the stock bumper, the slender rectangular horizontal bar at the left hand side of the photo that sits under the back up lights, is actually rivited to the top of the bumper guard. I can't figure how this part is fixed rigid without the bumper guarg in place. Maybe its not...

Yes, I think that thats the C4 Lightweight setup with the separate twin exhausts.

Dave

Jasko

Does not look like any heat shielding is necessary on that setup.

J richard

The PET diagram shows a "retaining strip" both front and rear that appears to hold the weight of the center of the bumper. It appears to screw to the body under the reflector, and then the bumper cover is attached to it. As far as I can tell, and I have both bumper covers off my racecar right now, (sans rear bumper reinforcement) the covers are supported at the top by the retaining strips shown on the PET breakdown of the bumpers, and by the bolts directly to the bottoms of the front and rear fenders, then the front bumper is supported by the attachment at the undertray directly to the body via screws, and the rear is supported by two pressed steel brackets that attach to the bottom of the bumper lip and attach directly to the bumper reinforcement. (it's these that are replaced by the two struts shown on the C4 lightweight car)
and of course there are the two outriggers that come off the bottom of the fender that also support the lower edge of the wheel cutout, those are pretty obvious. For the most part the bumper covers are pretty much free of the bumper support, save the rear lower mounts.

The C4 lightweight obviously can get by with no heat sheilding, but I'm trying to run a cup bypass/gpipe in a hollowed out bumper. Do you think you need the heat sheild for that combo?

JC in NY

European Carrera Cup racing cars ran no front bumper support. The tow hook was in the body. They ran the stock rear bumper bar with the tow hook in the stock location.

I recommend putting the bumper bar back in the front if you have one of these cars. Without it a very minor front collision can go front cosmetic damage to *major* sheet metal damage.

Strokher Racing

When you remove the front and rear bumpers has anyone had issue with the bumpers flopping or sagging?

Cupcar#12

Front no. its not part of the bumper outer casing - rear it is and you nee dto Fabricate something to hold the skin or buy the FVD stuff (if they still make it) to hold it up.

DaveConn

FWIW,

This past winter we pulled a lot of weight out of the rear end of my car, the rear bumper support being part of that. Jeff Gamroth @ Rothsport fabricated a nice, light and simple aluminum support strip, that attaches just below the reflector, to support (primarily) the center section of the bumper cover. You might try contacting him to see if he can fabricate something.

Regards,

Dave

pete000

The RUF bumper bar looks like a stock beam with the center section milled out. Bill V. has his 993 bumper bars drilled out to save some weight. I was pondering this too. Running nothing would be lightest of course but also most risky.

There sure is a lot of heat shielding material back there in the rear as well. I was wondering if the bumper cover would deform from the heat if all that was removed?

I would think around 10 lbs could be machined out of the bumper beams and save a bunch of $$ over the carbon composite beams that are so expensive. I wish someone would make up a set here cheaper. Composites are getting so much cheaper these days.

Strokher Racing

Do you have a picture of what you fabricated on the rear in place of the beam?