rear seat delete

[rccktmn2]

roll bar

So the upper bars are going to the upper control arm mounts and the lower bars are on the lower control arm mounts? I've got an 87 with a 455 and my cage is through the rear speaker holes and I don't have the extra bars going to the control arm mounts.

 

[shotgun]

itsnotanova, the frames on these cars are about as strong as a wet noodle.

Anything you do to stiffen it up, will help.

I added (from various gbodies ) just about every brace GM to my wagon, what a difference.

It is no slouch in the handling department, Fbody hollow font bar,1" rear bar, poly everywhere , Monte SS springs, boxed lowers, 255/60 15 Yokohamas etc etc.

What really blew my mind was how the steering was so much quicker. Turns out the front frame rails were flexing!

Some type of a down bar from the firewall to the frame makes a huge difference.

If you never go to the track, you can build the bar how you want but I would still use NHRA book as a guideline. There is a reason they require what they do.

The other big change was the rear trailer hitch. Both front and rear frame rails are floating in space, tieing them together stopped all my tailgate rattles and squeaks.

On my race car I made braces to tie the bumper mount together. It is just a boxed piece of angle iron. It reduced my frame twist by 75%.


rccktmm2,
"So the upper bars are going to the upper control arm mounts and the lower bars are on the lower control arm mounts?"

Yep that is correct. I did also make my own brace for the rear frame rails as I mentioned above.

I will add some pictures in a bit.


** batteries are dead in my camara, maybe tomorrow**

 

[itsnotanova]

Thanks for the tips! I can't believe I didn't think about tieing the bumper mounts together before. When you get batteries for your camera, take some photos of the firewall tie-in you're talking about. I've never heard of that before on a gbody. Strut suspensions yes.

 

[rccktmn2]

bumper brace

So you took a piece of angle iron and welded it across the frame rails in the rear. Do you run a rear sway bar? I could see this helping alot no matter what you do with your car since the frame rails aren't tied together until they reach the rear diff but I think if you had a rear sway bar that would eliminate most of the sway anything past the rearend is trunk space anyhow.

 

[shotgun]

rccktmn2, I have to disagree with your comments.

First, I am trying to help, not pick a fight. 😀

A rear sway bar may put more load on the frame.

It does control sway, but does nothing to strengthen the frame.

I have 3 gbodies and have had many in the past.

I put my wagon on the lift and can flex the frame by hand!

Granted I am not a little guy but never was able to do that on an Abody.

So I decided to do something about it.

The frame was put in the worse case position, jack stands under the frame just before the rear tire, everything from there back hanging.

I took measuremnts while twisting/loading the frame,then installed the brace.

It DID reduce twist and drop by approx. 75%.

Also did the same up front with similar results.


itsnotanova, remember you asked!!!

Here we go.

Here is a front bar you can buy that works with the frame to cradle braces.There is also a company ,local to me, that make a brace that is the cradle brace and tie bar combined. I just remember thier name.

Hers mine. I like making stuff,l if I was to do it again, it would be tubular but sometimes you work with what you got.You can also the X brace from a Grand Prix. The aluminum is just a cooler mount.

"My" design attaches on 2 planes.

Still working on the d/s down bar. Attaches to the firewall and to the upper a arm bolt ( stolen idea from Herb Adams).
The bar is a S10 bumper bracket! :lol:

On the P/S made a small bar between the frame and body. Can't use the same mounting point since there is no firewall there (a/c heater creates a big hole).It's 1/2 a S10 bumper bracket.

The back seat has Gran National braces.

This is the only shot I took while prepping the rear LCA mount.A plate was made to cover/attach the hole area to the frame amd then the down bar welded to it (the plate).

You can buy these braces for the same area on the net.

Sorry but same story on the UCA mount area, just starting prep shots.

Here the rear brace. In hindsight, would have made a plate to hit all three bumper mount bolt holes. At one end it uses only one bolt. I torqued it to hell but I guess it could be a pivot point.

Hope that helps.

 

[itsnotanova]

You've inspired me and I'm probable going to use some of your ideas. Thanks a lot for the picks. The bars you have going from the fire wall to the frame, how much did that effect things? I'm thinking that would make the car too stiff. Like you would feel everything or am I wrong?

 

[shotgun]

Those little bars really helped alot.

My opinion is the chassis can never be too stiff.

Notice I said chassis not suspension.

Shocks/springs and to a lesser amount bushing material ( body/suspension) effect your ride not a stiff chassis.

Why hang good parts on a wet noodle. You will never see the full potential of the suspension while the car is flexing.

High end shock don't even have rubber/poly bushing, they go with hiem joints.

Also for tuning, no flex is just one less thing to account for.

If you want a good all around balance use Edelbrock IAS shocks and progressive coil springs.

I never put "poly" in the upper ears of the rear. Either go with good (GM) rubber or right to sperical ( TRZ ). Poly is good for things that move on one plane, like your rear LCA, it binds when twisted.

 

[rccktmn2]

sway

Sorry shotgun I didn't mean to put you down or incinuate that anyone is right or wrong here. I've never heard of the mods that you have done and I find them interesting. I have 2 g bodies, one is an 87 442 and the other is a regular cutlass with a 455. I've had no problems with the 442 however I know most g bodies have alot of sway especially when cornering, the 442 has front and rear sway bars and it doesn't sway a whole lot and it handles pretty good for a g body, however if you compare it to a camaro or firebird or mustang then there is no comparison, those cars are meant to handle like their on rails. Thier center of gravity is lower etc, etc. My cutlass is going to be mainly a straight 1/4 mile car but will be driven on weekends to shows, etc. and there is alot of sway when going around corners but has no rear sway bars and I'm wondering if that would help instead of putting on the extra weight with braces. I also junked a g body frame over the weekend and before I took it off I did twist the rear frame rails by hand and they were very flimsy and they are usually the first place to rot out also. The front frame rails were very solid and wouldn't move but they are boxed in and you have the engine tying everything together right there. So I see your point in tying things together and the photos did help alot. Thanks.

 

[shotgun]

rccktmn2, No problem here. I put my " not wanting to start a fight" in my comments just to say it is not a personal attack in any way.

It's tough on the internet without being able to hear someones voice or see thier face.

We are good. 😀

I have both handlers and race cars also.

They both benefit from stiffer chassis.

I also hate extra weight, how many guys do you know lightened their steering column , made a aluminum glovebox door, runs plastic marine horns, etc etc. lol

I carved almost 700# out of the GP in my avitar. It weighed 3700# and now is 2950#.

Yes, sway bars do help with sway.

Just imagine how much better the car would feel if the bars were allowed to do thier job by being attached to a stiffer platform.

Again, this not directed at you, but I only give advice or share information from first hand trail and error.

There are quite a few "keyboard" mechanics out there giving advice based on a magazine article or ........

Tell me about your 455 powered Cutlass.
I assume it's a Olds 455?

"My" 455 is of the Pontiac varity making it Oldsiac or a Pontmobile?!? :shock:

 

[Vern]

Shotgun, Thanks for the pics and info. The firewall to frame is a new idea to me and I have been crawling around these cars for years. I have strengthend both my gbodys with criss cross trunk braces, GP fender to core support, X across radiator, Jounce bars with the front bar to complete the triangle. I don't weld and have to pay someone to fabricate so I don't do alot of it. I would like to get my hands on a brace that ties the rear frame rails together in front of the bumper.