Help with a ‘deformed’ rear lower panel please

[Mike]

Hi there other members !
I’m afraid I’m not very technical so hopefully someone else who is might be able to guide me in the right direction.…
I noticed the other day that I appear to have ‘deformed’ my passenger side rear panel, just under the bumper, per the attached photos (I’ve also scratched the panel but that will be a fairly quick fix hopefully), as I was reversing into my garage.
My question is….is this because of some material on the inside of the bumper that’s designed to deform on a low speed impact (as my Regional Rep, Gary, suggested when I asked him but also suggested I ask my fellow members, hence my post), and would I be able to see it if i jack it up ?
my next question is, is this a ‘self fix’ or will I need to take it in to be repaired because it needs new material behind the bumper (in which case I was intending to take it to Autopics, not far from me in Worthing, West Sussex, as I think the gaffer there is a member here as well.

and finally, I have been thinking about replacing the exhaust with either a Magnaflow or Borla system in order to try and get a ‘V8 rumble’ from it, as my straight through system sounds a bit ‘weedy’, or am I expecting too much ?

cheers
Mike

 

[Nassau65]

To repair properly the services of a body shop are needed.

 

[johng]

Looks like you've got a 79, which I think is probably similar if not the same as my 78. My guess is that you've bent the bit shown by the green arrow in this photo. Well actually the part on the other end of the crossmember, but I don't have a photo showing that end. You might be able to re-shape this bit , but you'd have to remove the bumper cover to get at it

I didn't refit this part when I rebuilt my car because I fitted a fiberglass rear bumper and this bit wouldn't fit underneath it.. This photo shows what is under your bumper cover (minus the bits at each end that I didn't refit).

If the bumper cover is original then it is a rubber and "might" pop back out with some gentle persuasion.

 

[Chuffer]

I believe the deformable bumbers are made of polypropylene . As Nassau said , a professional body shop repair would be the best bet to get a good finish .

 

[Mike]

Thank you so much chaps, appreciated.
Do you happen to know if I’d need a specialist body shop (I’m thinking Autopics because of their location close to me and connection to the Club via Dave Clarke, the owner) because of the bumper material ?

cheers,
Mike

ps. Any thought about the possible change of exhaust system ?

 

[Chuffer]

Thank you so much chaps, appreciated.
Do you happen to know if I’d need a specialist body shop (I’m thinking Autopics because of their location close to me and connection to the Club via Dave Clarke, the owner) because of the bumper material ?

cheers,
Mike

ps. Any thought about the possible change of exhaust system ?

Best bet would be to ask if the body are exprienced in glass fibre and poly repairs as it`s not the same technique as normal panel bashing . As for exhaust system , I have a decatted straight through system with original manifolds and Supertrapp Tail mufflers on my 1980 . Plenty loud for me but too loud for the wife !

 

[Forrest Gump]

and finally, I have been thinking about replacing the exhaust with either a Magnaflow or Borla system in order to try and get a ‘V8 rumble’ from it, as my straight through system sounds a bit ‘weedy’, or am I expecting too much ?

cheers
Mike

You should definitely be able to get a decent noise from your car. Modified engines will of course sound racier, but a stock motor can still sound great.
Magnaflow or Flowmasta are popular choices of muffler. Borla tend to be systems for the later cars C4 on.

Have a look at this previous thread on the topic: What rear mufflers are you running if not stock?

 

[Roscobbc]

You really need to investigate things a little further before any action - IF the rear bumper/rear panel assemby has been replaced with a 'plastic' unit (quite a common thing as they hold their shape very well - unlike, quite often the stock component) then the use of hot/boiling water could potentially 'pop' the depression out of the part (just leaving you with scuffs. Its a 'known' treatment for plastic body parts.
Is the exhaust a 'one in to two' system - i.e comes off exhaust manifolds as two pipes - then joins as one and then splits back in to two at the rear. That'll need replacing if you want the full 'aural' effect. As Forest Gump suggests Magnaflow are a good choice - the're absorbsion tube mufflers - have a nice businesslike, not too strident to be uncomfortable in the car, yet crackle nicely when pressing on.

 

[johng]

I believe the deformable bumbers are made of polypropylene . As Nassau said , a professional body shop repair would be the best bet to get a good finish .

Not wishing to be picky, but the bumper covers are made of urethane not polypropylene. It's a very flexible material, I would try and get your hand or other implement onto the back of the depression and see if you can pop it back out. The paint looks cracked, so you are going to need to do something about that as well.

 

[Nassau65]

Not wishing to be picky, but the bumper covers are made of urethane not polypropylene. It's a very flexible material, I would try and get your hand or other implement onto the back of the depression and see if you can pop it back out. The paint looks cracked, so you are going to need to do something about that as well.

The front/rear “bumpers” were indeed made of urethane from GM. sometimes they didn’t weather so good depending on the climate where the car was. They became very wavey and sometimes brittle and cracked. Lots of owners replaced them with fibreglass replacements over the years. From the picture of damage it looks to be an original bumper. To make the car look nice again a professional would be needed unless you have the necessary skills to do it yourself. Don’t spoil the ship for a hapenth of tar.

 

[Chuffer]

Not wishing to be picky, but the bumper covers are made of urethane not polypropylene. It's a very flexible material, I would try and get your hand or other implement onto the back of the depression and see if you can pop it back out. The paint looks cracked, so you are going to need to do something about that as well.

I know it had a poly in it somewhere , just got the wrong sort of parrot !

 

[Mike]

Thank you so much for all your advice chaps, it makes a big difference to know you'll get friendly, helpful advice even though it may seem a basic question. I'll take Nassau's recommendation and get a proper job done, especially as it will also need the scratches sorting out, and she is otherwise in good nick for an old girl, although I will look further into the Magnaflow suggestion of Forrest, as this was the one I had settled on a while back, but never actually did anything further - she had to have a crate engine fitted by Steve at Dart Corvette in Leigh a few years back, after she ate 2 of her pistons on the way back from a Goodwood Breakfast Club meeting. I seem to remember Steve suggested a "Stage 2" engine as it would be the most "road friendly" option, rather than the off/on rocket ship of the more powerful ones available. Not sure on the bhp, but I seem to remember him saying something like 350bhp at the flywheel, does that sound likely ? She's has a 3-speed auto box, and if you run through the gears she picks her skirts up and shifts, spinning the wheels as she goes through the changes, but I just usually leave her in 3rd and its a kind of "lazy" acceleration...

 

[Mad4slalom]

Hi there other members !
I’m afraid I’m not very technical so hopefully someone else who is might be able to guide me in the right direction.…
I noticed the other day that I appear to have ‘deformed’ my passenger side rear panel, just under the bumper, per the attached photos (I’ve also scratched the panel but that will be a fairly quick fix hopefully), as I was reversing into my garage.
My question is….is this because of some material on the inside of the bumper that’s designed to deform on a low speed impact (as my Regional Rep, Gary, suggested when I asked him but also suggested I ask my fellow members, hence my post), and would I be able to see it if i jack it up ?
my next question is, is this a ‘self fix’ or will I need to take it in to be repaired because it needs new material behind the bumper (in which case I was intending to take it to Autopics, not far from me in Worthing, West Sussex, as I think the gaffer there is a member here as well.

and finally, I have been thinking about replacing the exhaust with either a Magnaflow or Borla system in order to try and get a ‘V8 rumble’ from it, as my straight through system sounds a bit ‘weedy’, or am I expecting too much ?

cheers
MikeView attachment 16624

There are some good you tube videos on how to apply heat and cold to teformable panels to get them to return the their pre damaged form. Have a google