Removable backbone retrofit

[Ophitoxaemia]

I've been contemplating this project for many years and wanted to share the results with the community.

We recently completed a backbone retro fit into my car, FFR 1630. The twist was I wanted to be able to take the transmission out the top, and so it needed to be removable. 750lb front and 1000lb rear springs with good shocks rendered my Mark I chassis practically untunable for autocross.

Here's a pic of the completed project: http://thevenom.net/cobra/backbone/backbone_top.jpg

We were able to make the front cross pieces wide enough so that both the front diagonals tie directly into the bases of the motor mounts on each side. The rest of the design is very similar to that found on newer cars.

I can report that the car rides much smoother on the freeway, the door latch doesn't rattle on city streets, and it's been fast(er) at autocross.

This project could not have been completed without the expertise, help, and generosity of Dan Pellow, David Borden, and Russ Thompson.

James

[CraigS]

Excellent. I would also like to see some pics of how you tired in to the motor mounts. My MkII has the FFR backbone but I've always wondered why they stopped it where they did near the firewall and didn't tie in to the front suspension. Seems to me some tubes running to the motormount and then on to the front suspension coilover mount would be a good thing

[Mike N]

Nice work. The backbone mod is on my list of upgrades just didn't get to it yet. As with Craig I would really like a little more insight into exactly how you configured the tubes at the motor mount, firewall and behind the seats. Do you have any pictorial views of your FEM or more detailed photos?

[Ophitoxaemia]

I can only speculate, but I'd guess that the factory design allows a wider range of bell housings and engines to be used. I can take more pics, but it's pretty cramped in there, hard to see. Most of the tubing was mocked up near a mark IV frame for reference.

[skullandbones]

Ophi....,

Have you removed the trans yet? Just wondering how the mod worked. Thanks, WEK.

[Glenn31Y]

Exceptional information can be found on these kind of boards. Cheers men.