Author Topic: Has anyone done anything besides SFC to stiffen the rear of the car?  (Read 959 times)

Updated71

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Besides a cage and SFCs has anyone done anything to add a bit more rigidity to the rear half of the car? Possibly across the torque boxes, rear seat divider, etc.?
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skisix38off

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Hmmm....  Where are you going with this?  What are you wanting to do that making the rear more rigid would make a difference?

Updated71

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Hmmm....  Where are you going with this?  What are you wanting to do that making the rear more rigid would make a difference?

I am hearing what I believe is body flex back there in the form of a creak. Nothing seems to be off or out of place. I was talking to a guy at a cruise night a couple of years back that had the same issue on a fresh restomod with very little drive time. He hadn't diagnosed it as of that time.
The surgeon general never said nuthin' 'bout smokin' the competition!

skisix38off

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Re: Has anyone done anything besides SFC to stiffen the rear of the car?
« Reply #3 on: June 02, 2022, 10:01:17 AM »
Hmmm....  Where are you going with this?  What are you wanting to do that making the rear more rigid would make a difference?

I am hearing what I believe is body flex back there in the form of a creak. Nothing seems to be off or out of place. I was talking to a guy at a cruise night a couple of years back that had the same issue on a fresh restomod with very little drive time. He hadn't diagnosed it as of that time.

Not trying to change your mind, just curious.  Could the creak be from suspension movements?  Those frame rails, while boxed, are pretty thin.  Perhaps you could install a cradle to attach the two sides together and perhaps that stiffens the rear.

Updated71

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Re: Has anyone done anything besides SFC to stiffen the rear of the car?
« Reply #4 on: June 02, 2022, 11:46:05 AM »
Hmmm....  Where are you going with this?  What are you wanting to do that making the rear more rigid would make a difference?

I am hearing what I believe is body flex back there in the form of a creak. Nothing seems to be off or out of place. I was talking to a guy at a cruise night a couple of years back that had the same issue on a fresh restomod with very little drive time. He hadn't diagnosed it as of that time.

Not trying to change your mind, just curious.  Could the creak be from suspension movements?  Those frame rails, while boxed, are pretty thin.  Perhaps you could install a cradle to attach the two sides together and perhaps that stiffens the rear.


That's exactly what I was thinking. I pulled the seat and was trying to think of something that would work from one side to the other and still allow the seat. There is no room at all underneath with the exhaust.
The surgeon general never said nuthin' 'bout smokin' the competition!

Re: Has anyone done anything besides SFC to stiffen the rear of the car?
« Reply #4 on: June 02, 2022, 11:46:05 AM »

NOT A TA

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Re: Has anyone done anything besides SFC to stiffen the rear of the car?
« Reply #5 on: June 02, 2022, 07:39:28 PM »
If the car has poly or solid body mount bushings remove the body bushings and grease ALL of the surfaces that touch each other. Use the special poly grease if poly mounts are used. Don't be cheap with the grease, just clean off excess afterward with wax & grease remover.  Also note that poly mounts don't work well with connectors that utilize the body mount as one point (causes creaking) and that really, only solid mounts should be used with any connector set up.  Also apply grease to frame connectors on all surfaces that contact the vehicle. I know it seems wrong but just do it.

At one time before the crash I had a thread about frame connector install but it was lost, perhaps I'll copy and paste it back onto this forum sometime. Anyone interested can go to this thread on another forum and scroll down a few posts to see the PTFB frame connector installation instructions. https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/70-firebird-the-14-car-performance-therapy-project/72356/page10/
John Paige
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Updated71

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Re: Has anyone done anything besides SFC to stiffen the rear of the car?
« Reply #6 on: June 03, 2022, 03:13:05 AM »
Thanks John! I have solid bushings. The noise is definitely from the rear of the car, but I’ll try this.
The surgeon general never said nuthin' 'bout smokin' the competition!

NOT A TA

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Re: Has anyone done anything besides SFC to stiffen the rear of the car?
« Reply #7 on: June 03, 2022, 08:35:06 AM »
Thanks John! I have solid bushings. The noise is definitely from the rear of the car, but I’ll try this.

If you have spare tire/jack take them out and go for a drive also. Sometimes a spare that's lost some pressure can then cause a creak.
John Paige
Lab-14.com

Updated71

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Re: Has anyone done anything besides SFC to stiffen the rear of the car?
« Reply #8 on: June 03, 2022, 01:19:09 PM »
Thanks John! I have solid bushings. The noise is definitely from the rear of the car, but I’ll try this.

If you have spare tire/jack take them out and go for a drive also. Sometimes a spare that's lost some pressure can then cause a creak.

That I don't, but thank you for the advice.
The surgeon general never said nuthin' 'bout smokin' the competition!

Re: Has anyone done anything besides SFC to stiffen the rear of the car?
« Reply #8 on: June 03, 2022, 01:19:09 PM »
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