Moving me forward of the original firewall really changes the frame design. And I’m not just talking about swapping the seat and gas tank around, either. The original frame could be considered an exoskeleton as almost every part was outside of the body to some degree in order to increase torsional stiffness. Well the new frame is much smaller, only 27″ wide to fit the firewall on the body, up to the point the engine and drive bits mount which will have to be wider because of the transverse mounting.
Basically the part of the frame forward of the firewall are going to be like a ’50s Indy roadster. This is still going to be hella stout and light, but the frame members are going to be different than the Sprint-T derived frame. This frame is going to be designed for a mid engine from the get-go instead of trying to cram a mid mounted engine in a front engine frame. The other major change is all of the frame is going to be round tube, most 1.5″ diameter and most 0.060″ wall thickness except for the bits around me that have to be 0.120 by SCCA rules. This will lighten the frame by a few pounds, but nothing spectacular. What will do the most to lighten the frame is tucking everything inside the body and doing the engine and transmission mounts first instead of making them fit what was already there. Also the Sprint-T was designed around a roll cage that won’t be there because the driver isn’t where the roll cage is designed to protect.
I can make this frame as stiff and light as the Sprint-T, it will just take a bit more brain work to do so. Instead of spreading the frame as far apart as possible I’ll have to concentrate on using internal structure for stiffness. It can be done, and I’m the guy who’s crazy enough to do it. Incidentally, the changes move the fuel tank right over the center of gravity of the car so the balance doesn’t change at all between full and no gas. The Princes of Serendip are victorious again! (Look it up)
On other fronts I need to get that brake hone this evening so my walk will be extended to the auto parts store. And tomorrow’s walk will be by the pharmacy to pick up more not-sad pills for my brain. Tonight I’ll be walking about 3 miles to get some bonus check-ins on my mobile game. I haven’t been able to walk as a workout for 2 days now and I need to stretch out a bit.
More later.
Witch on a Bicycle 