Ruined Regal

[Clone TIE Pilot]

🙂

The roof of a conventional car is essential to the stiffness of the chassis. The roof helps keep the car from twisting and bending. Building a car without a roof is a bit like building a suspension bridge without the overhead cables. As such, the bottom part of the structure of a convertible has to be stiffened considerably. Heavy reinforcing brackets have to be added to the body of the car. This is why convertibles often weigh more than their fixed-roof counterparts. Anyone who doesn't understand this shoud not touch a car let alone post any advise on a car forum as it would be ill-advise. Sadly it seems many members here don't understand basic structural engineering and load paths or even care to. They rather just use ad hominem attacks, the fallacy of attacking the man instead of attacking the argument. Equating someone's character with the soundness of their argument is a logical fallacy.

 

[pontiacgp]

A friend of mine with a 76 Chevelle hard top twisted the body enough so the doors won't close without slamming them. He never boxed the frame and he has a BB motor with about 650 hp. Another friend of mine has a G body t-top car that he can just about lift the front end off the ground and with a boxed frame the body has not shifted. I have about 450 hp in my T-top GP and although I don't drag the car is set up to take corners it does well with the hollow sway bar combined with the spring it has a rate of over 850 lbs in the front and over 225 lbs in the back. My doors are still lined up cause the frame is boxed and all the factory welds on the frame are upgraded. These cars came from factory with well under 200 hp so the frame and body did work together but once you put some power under the hood and set the car up to handle corners the frames has to be upgraded, not the body. Years ago during a winter a buddy's older bother stuffed a 289 into my MGB, it lasted one nite and after a few beers we decided if the car twisted going forward we could untwist it back up. The police were not amused....🙁

 

[Clone TIE Pilot]

Solid roof cars always have an advantage over non solid roof versions. Reinforcing the frame is just half the battle. The body should also be reinforced as the two work together.

G bodies frame and body work together much more than the more primitive construction of Chevlles, do they even use the windshields as load bearing members like G bodies?

For example, the rear seat brace in g bodies stops the body from pressing down on the rear frame rails which causes them to crack behind the rear axle hump over time. It spreads the load and stress over a larger area.