Im about to take off my rear bumper and take some aluminum square frames from work and fab one up for weight reduction. my question is that if the rear bumper provides any "stability" for the subframe that it will want to flex? Good idea or band idea?

 

First are you talking about the rubber honeycomb section or the actual metal bar it's attached to?

I'm guessing you mean the metal part. Let me preface this by saying I'm no expert and I assume no liability if you replace this part, but I would say in terms of providing stability to the unibody subframes I would say no, that piece probably has very little impact on keeping the subframes plumb and square.

However, in an accident I would say that even in the 80's, they probably engineered certain aspects impacting crumple zones and such. My concern would be the thickness of the aluminum you're using and also what you plan on using to fasten this piece. Aluminum isn't going to have the tensile strength of steel and while you're fine for daily driving, in an actual accident, that piece could fail quicker than a steel section. That is assuming your steel piece is in good shape and not rusted around the bolt holes. The aircraft industry has certain standards for fastening and material thickness when using aluminum. I would say researching those would be a good place to start if you're set on this course.

 

Take measurements and have a 1 5/8ths chromoly tube bent up. You can even make it a bolt in deal with the 4 holes on each side. It will be light and have very good strength. I have done it to mine and it supports the rear cover well. The only thing I had to do was zip tie the bottom up so it doesn't flap around.

 

thanks for the input guys

 

GM made an aluminum version of the front bumper.Some early 3rd gens have em, mine does.No rr version though.

There was/is a member here who made a tubular steel rr bumper many years back. JERRYWHO i think is the user name.

 

I made mine both front and rear with 1/2 inch aluminum channel stock and it has done a great job for the last few years and heavy abuse. With the rear unbolted it doesn'ts make much difference but I rode around for a day with the front crash bar disconnected and the car felt like a wet noddle in the corners.

 

Did you happen to take any pics of these? I'm looking to do the same thing.