Body bracing

[eagleguy]

As I am new to the GN and Turbos I would like to know what is the body bracing for that I see many have added to their cars, is it really needed and how do you know if a car already has issues from flexing?

 

[87GNSteve]

Some of the most economical and easy bracing to install is what GM already did to other g body cars. The Grand Prix and the Cutlass had what are commonly referred to as 'jounce' bars they triangulate the frame to the engine cross member.
The other brace found in the GNX and the Grand Prix is the rear seat brace there are a few different methods of bracing the area back their and that helps tie the two sides of the body together to eliminate flex. There are a few aftermarket kits to do this and if you have the lowest level of fabrication skill you can do this yourself.
Last issue is a little more involved to repair and that is the body mounts often they are not all included from the factory the GNX had 2 extra that Regals did not have. Replacing all of these 30 year old bushings makes the car feel new again.
You can see evidence of stress at the B pillar where the top of the quarter glass; body cracks form going towards the door.

 

[SHADOWII]

The signs are the cracks around the top of the "B" pillar and rear side windows. I even had the roof weld on the passenger side rear window start to buckle. Put the GNX cross bracing in to help prevent it.

 

[Chuck Leeper]

Change the bushings before you tie the frame and body up.

 

[T- Type Tim]

 

[GNVAIR]

My own car which was not raced that often cracked the frame crossmember right by the pinion snubber. I also notice the center brace between the trunk and back seat has stress cracks in it.

 

[HotAir6 v.2.0]

I added the resr seat braces in the trunk and noticed an immediate improved with the pillar cracks. That was 20 years ago. In the last few years we replaced the body bushings and added the bushings at the GNX location. Then I went to semi solid motor mounts and installed the SC&C jounce bar. I'm super happy. It feels so solid. No creeks over speed bumbs and it just feel more rigid. I'd recommend doing what I did.