Chassis stiffness without roll cage

[toomanymodz]

Ok, I've been noticing the typical 'roof buckling' pattern on my car for a while and I'm not sure if it's my imagination but it seems to be getting worse. Also the back of the passenger quarter panel has a slight buckle to it near the tail lamps and trunk lid is off a little, and I'm pretty sure it's from the car twisting as well.

I want to stiffen up the chassis, but I don't want to install a roll cage at this time. Emphasis is on a 'street car' look rather than a race car. Plus I've been putting the car on a diet (currently weighs 3350) and don't want to add 100+ pounds to it with a full cage.

I currently have the rear seat braces and the front chassis braces (that bolt between front cross-member and frame horns). I have yet to install the braces that tie the lower control arm mounting-point to the upper control arm mount.
http://www.summitracing.com/parts/upi-3028-b

While looking through some old posts, I came across this one:
http://www.turbobuick.com/forums/threads/frame-off-build-almost-finished.379103/

I like that bar that has been welded between the shock mounts. I'm going to have my chassis shop do me one like that. My question is, are there any other must-have braces that can be fabricated that provide a significant improvement in chassis stiffness?

My GN is a hard-top (no t-tops or moon roof). Typical 60ft times are 1.5x, soon to be 1.4x.

 

[Chuck Leeper]

Body mounts?? Maybe, try some poly mounts. 11.42?? U R already under the limit for a 5 point. [I'd not use it, but a 6 instead.]
That tie bar is going to do nothing to limit chassis twist.

 

[toomanymodz]

I've ran as fast as 11.18 with the old turbo on low boost. The new turbo should put me in the 10.90's provided that I run on a prepped track. I've thought about getting a race chip and running race gas, but with the signs that I'm seeing in the sheet metal, I want to address it first before adding boost. I'll have to look into poly mounts. I do believe they are still factory bushings.

 

[charlief1]

The center of the fame is where most of the flex is. What you might be able to do is do some sort of boxing in the center to stiffen it up. If you had a frame out of the car you'd realize how flexable they are.

 

[pacecarta]

go with HR rear swaybar , it will stop the twist on launch

 

["Reaper"]

Here is my cheap fix and works very well. I have no cage or any other frane braces. I welded a piece of 2" Chanel on both sides.

 

[toomanymodz]

Ok, I think my plan is this: Install the big rear sway bar. And have my local chassis shop box the frame like was done in this thread:
http://www.turbobuick.com/forums/threads/frame-off-build-almost-finished.379103/

That mod takes the frame from a C configuration and turns it into a D:
Thanks for the input y'all.

 

[BOP4ever]

I'm not clear did you take a piece of 2 inch channel iron and weld it to the bottom of the stock frame?
Or inside the c channel stock frame web?
Looking on phone I can't see it well enough to tell what exactly was done.
Thanks

 

[toomanymodz]

I'm not clear did you take a piece of 2 inch channel iron and weld it to the bottom of the stock frame?
Or inside the c channel stock frame web?
Looking on phone I can't see it well enough to tell what exactly was done.
Thanks

That's what Reaper did in the post above my last post. I'm going the route of welding inside the frame so that it isn't as visible.

 

[Red C5]

I think you're car has a lot more than 10.90's in it. I would start with where you are thinking.

 

[chopped39]

Someone on here had a brace built that went under the car and I want to say throught he floor and into the rear seat bracing

 

[Chuck Leeper]

One can add all the triks of the week, to stop/reduce the twist. Once he gets the faster time slips, he'll be sitting in the stands, as a spectator...........And, if it's relegated to street racing, a jail cell.

 

["Reaper"]

I'm not clear did you take a piece of 2 inch channel iron and weld it to the bottom of the stock frame?
Or inside the c channel stock frame web?
Looking on phone I can't see it well enough to tell what exactly was done.
Thanks

Welded it to the bottom of the frame from the thick part just behind the front tire to the think part just in front of the rear tire. Point the triangle part to the ground. I hade to make some tabs on the inside part of the C Chanel part of the frame. If your frame is not straight from jacking it up there.

 

[FASTV6HENRY]

That's what Reaper did in the post above my last post. I'm going the route of welding inside the frame so that it isn't as visible.

Hey brother i am in South Orlando...we need to hook up after you get that done i really like your build with the car and mine is going the same rout. i am very interested on the same chassis reinforcements i also want to keep a cage out of my car as long as possible. i also would like to know who is your chassis guy...pm me and i will give you my number. but either way i am sure will see you at the Buick GN show in Feb at Old Town

 

[dr_frankenstein]

screw it street race it!

 

[toomanymodz]

Hey brother i am in South Orlando...we need to hook up after you get that done i really like your build with the car and mine is going the same rout. i am very interested on the same chassis reinforcements i also want to keep a cage out of my car as long as possible. i also would like to know who is your chassis guy...pm me and i will give you my number. but either way i am sure will see you at the Buick GN show in Feb at Old Town

I'll definitely be attending Old Town. You're welcome to come see my car any time. The goal with mine was to keep it a street car with working A/C, cruise etc., yet be 10 sec capable on straight pump gas with no alky. I think I've done that...just need to get to a prepped track and crank out a high 10 sec pass. Stiffening the chassis , Moser axles, rear bar by HR Parts, and T/A rear girdle are the next mods.
My chassis shop is Miller Race Cars and they're located next to the Brooksville airport.
http://www.miller-racecars.com/

 

[chopped39]

One can add all the triks of the week, to stop/reduce the twist. Once he gets the faster time slips, he'll be sitting in the stands, as a spectator...........And, if it's relegated to street racing, a jail cell.

Alot of people want to go fast and they think they are going to be safe. If your twisting your car put a cage in in it. Look at scott's car when it went over. If there would have been no cage at all he wouldnt be building his next car right now. I saw a car go over in a street race in chicago back in 94 .It was a big block 2nd gen camaro with no cage .He was pulling hard through second gear so he might have hit 80- 90mph. That roof lasted 3 seconds and it was smashed flat and killed the driver.Going a 100+? It dont take much. but safety is the number one rule in this sport. Good luck to all and be safe .

 

[turbonut85]

Another way to stiffen the frame would be to weld the rails solid along the top and bottom of the factory boxed sections....they were only spot welded from the factory....makes a significant difference.

 

[charlief1]

Are you talking about the front and rear sections of the frame Keith? Mine were welded all the way and there's no spot welds on the frame. The welds were crappy but they were fully welded.

 

[BGNeXtreem]

There isn't a Dam turbo Buick any were that hasn't street raced somebody if you say so you know your a Dam liar if you havnt street raced any body in a turbo Buick sell it because you punked out