Frame Tubing Dimensions?

[redss86]

Just wanting some opinions on what size rectangular tubing I should go with? I am going to be rebuilding the rear 2/3 of my frame for my Monte Carlo SS. I will be using the front portion of the frame, from the front torque boxes forward. From there back I am going to build the rear portion of the frame out of either 2x4x.125 or 2x3x.125 tubing. I will be running a truck arm rear suspension with braces going both from the t/a crossmember forward and back. I would like the frame to be tucked away so that you can't see it below the rocker panel, this is why I was thinking about using the 2x3. There is right at 4.25in from the body mount surface to the bottom of the pinch weld on the rocker panels. I am not planning on building a gauge if I can keep from it.

Also, I was thinking about going w/ factory type rubber body mounts. I plan on using this car primarily for daily driving purposes w/ the occasional track visit. I know that a solid mount would be better, but my rear suspension will be mounted w/ heim joints and front will be along the same lines (SC and C's greasable race bushings, unless recommended otherwise). So w/ the suspension being mounted this solid, I was wanting some sort of isolation from the road noise the suspension will produce. Urethane bushings are an options, but I have heard they also transfer alot of noise.

Any and all help would be greatly appreciated.
Thanks, jmarti81

[Tig Man]

I would use the 2x3, it's the standard used on cup cars. 99% cup cars run the stock rubber bushings in the truck arms. Even to the point of using a bigger diameter rubber bushing on the short tracks and road courses. It don't shock the tires as bad as monoballs.


Mark

[redss86]

I know cup cars use 2x3, but they also have a full cage in them for strength and rigidness. I just don't know if it will be strong eough to resist all the stress it would receive on the road and the track?

One thing against the rubber bushings in the truck arms, is that I already have the arms w/ monoballs. How much shock would the tires receive, and how bad would it be?

[boodlefoof]

I think 2x3x.125 should be plenty. Probably tie it together with a cross bar or two or an x-brace if you aren't welding it to the floor.