Phil Ehlen

I've seen a few threads on modifying the rear bumper of the later model year 911's with the larger bumperettes and added that as my third project on my 1988 Carrera.

I noticed some corrosion on the bottom of the bumper while replacing the Cat during my last project, so I knew there would be some restoration involved in addition to this mod.

First pic is just the beginning. Second pic shows the corroded nut that I will need to cut off.





My plans are to just removed the bumperettes, fill the wholes sand, treat and paint. However, if I need to do some work with the bumper shock stud I just cut short to get the corroded nut off, I may just go with the flow and do a complete smooth rear bumper. Two things holding me back: I think the back matches the front better with the left and right bumper rubber AND I don't own a welding machine. Hmm - I really want a welding machine (I guess TIG for aluminum) and learning to weld is on the bucket list...

Phil Ehlen

After a lot of Internet research, I understand that the aluminum bumper will need a conversion treatment for best prep before painting.

After some search, I found this: Henkel Alodine 1201 Chromate Conversion Coating. Looks like it will do the trick.

(As an aside - looks like this would be a possibility for caliber refurbishing to get the gold colored coating that was on new original calipers??)

(As and aside #2 - saw a coating for magnesium alloy that resulted in a gold color and I have put this in the blackboard to look into for the fan and fan shroud).

rusnak

I was almost rear-ended tonight. But except for a quick right foot and acceleration, I would have been. Those big bumperettes do their job up to a surprisingly big hit. I was rear ended once by a Toyota Celica, and although the Celica front was completely smashed up, my 911 bumper was knocked off center just a small amount. A few adjustments of the bumper bolts, and you can't even tell it was ever hit. Even the big ol rubber bumperettes look fine.

IMO, from an aesthetic standpoint the mass of the rear flares and the addition of the tail balance out the larger bumperettes nicely. If you had a pre-78 with a narrow body, then not so much.

500

Yeah, bumperettes are one of those things that you think you "gotta" change based on what everyone say, but then one reflects and realizes there is an upside to them!

Plus, they really don't look that bad.

Phil, the calipers are iron or steel. I don't think the conversion coating will provide good long-term corrosion protection.

For refinishing calipers, the main choices are:

1) re-plating for a stock look.
2) Powder coat - good long-term durability
3) High temperature spray paint - maybe not as durable in the long haul, but still a pretty decent option.

GothingNC

I am keeping mine stock, twice I have been tapped in the back twice this year while I was in my VW stopped at a red light.

They come in handy to use as a small beer table in the garage.

John

wildcat077

I thought about removing the bumperettes at one point as well but every time i back into the garage and bump my son's ATV with the rear bumper it reminds me why i kept them on ... lol

Cheers !
Phil

Phil Ehlen

All good points, but I'm going to take my chances on going the no bumperettes mod. I looked at the smaller euro bumperettes and decided against that too. I did decide that the two rubber strips will be reinstalled (actually, one will have to be replaced due to massive rust).

It will take me a while, but I'll take pics and document it for anyone else interested.

Ed Hughes

Cheap insurance, I'll never remove mine. Too many idiots out there, and as noted, they don't look that bad and offer decent protection, which could avoid a more painful repair. I had a buddy that was going to make a shallower (same footprint) replacement, but dropped the project.

Then, as you note, you have to deal with what you find underneath.

VERBOTN

I had a Toyota Camry (sp?) climb my backside when I was at a stop light, regretfully the PCNA bumper-et's were not in play. Keeping them despite their hefty weight, I mean really those things are HEAVY

nolift911

Not sure I agree with some of the logic here on keeping the tumors for "safety" - they may help you from the ocassional parking idiot but the safety side of things come from a solid bumper mounted to shocks or collapsable tubes to the chasis - for energy and impact absorption (in a real accident - not a fender bender)

With the tumors removed if someone hits you, yes you will likely be required to paint the bumper - with the tumors on and you get hit, yes you will likley be required to paint the bumpers (they don't slide nice and smooth inside of the bellows, and under the rear panel - they get scratched and gouged and will need to be reapinted anyway, and that is if the idiot squares up nicely with you for a straight on hit.

If done right - they look nice IMO (no bolt holes, rubber trim holes etc) and you still retain all of the safety benefits. I went with the lighter weight euro crush tubes "while I was in there"

Plus you lose a ton of weight in the wrong place on the car.

Phil Ehlen

Nolift911 - did you remove the front bumper rubber too?

nolift911

Yes....

Ed Hughes

Not so sure it's about safety, as much as PIA is someone taps the bumper.

theiceman

love the oil holder rack ..

nolift911

Right - and that is my point. I had someone "tap" my rear bumper with the tumors on and I got a nice set of scratches on the top of my bumper where it receded in due to the shocks - needed to be repainted anyway. Just saying the logic doesn't really hold if you keep them on to avoid a PIA factor - if someone hits you tap or smash - it's a PIA regardless. Rather lose the weight and have the bumpers look clean.