Thread: C5 gto
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Old 12-12-2010, 12:29 PM
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heinke heinke is offline
MetalShaper of the Month Jan 2018
Join Date: Nov 2009
Location: Livermore, CA
Posts: 250
Default C5 GTO - the story continues

So without further ado, letís jump into the project. Hereís a couple of pictures of the chassis in ďgo kartĒ form.

I designed and built this chassis specifically for this project. Itís the first chassis Iíve designed or built so the juryís still out on whether itís a good design or just a mediocre one. The engine is a 2004 Corvette LS3 crate motor with 405 HP from the factory. Itís topped it with a Magnuson inter-cooled super charger that should bump it up into the 550 HP range.

Front and rear suspension is from a í98 Corvette. I designed the chassis to use the cast aluminum suspension cradles which use 4 bolts each to attach them to the chassis. Power is driven through a 6 speed transaxle which places a good bit of drive train weight back on the rear wheels. The engine is setback 12 inches from normal Corvette placement resulting in a 55% rear to 45% front static weight ratio. Normally a front engine car is heavier in front than rear but this one isnít. My goal is to get enough rear tire traction to minimize wheel spin but also get great corner handling as well. A 25 gallon fuel cell is squeezed in at the rear of the car to safety store the fuel.

Hereís the bare chassis after it returned from being powder coated:

The chassis has a built in roll cage meeting SCCA specification. Itís constructed of carbon steel DOM tubing the main structural and largest tubing members being 1.5Ē diameter. Thereís a mix of 1Ē and .75Ē tubing used for triangulation. All the tubing ďfish mouthsĒ were cut on a Joint Jigger with hole saws in my drill press. All the welding was completed with a TIG welder. I was a newbie at TIG welding when I started the project and needless to say, Iím quite proficient now.

I followed the chassis design principles of Herb Adams in his book Chassis Engineering. The main strength and rigidity in this chassis comes from the oversized transmission tunnel/backbone thatís fully triangulated on all four sides. Iíve found that I canít jack the chassis and raise one tire at a time, two tires always come up. I do get cracks from people that my design looks like the Masserati ďbirdcageĒ chassis.

I fabricated the chassis, assembled all the drive train, installed the fiberglass body and wired it up while the chassis was in bare steel. I wanted to make it drivable and verify I had all tabs and brackets welded on before getting it powder coated. After that, I took the whole thing back apart and sent it out for sand blasting and powder coating. The bare chassis with aluminum suspension cradles installed weighs in at 460 pounds. My goal was high strength while also being light weight.
Joel Heinke
Be original; don't be afraid of being bold!
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