Determining batwing centerline.


Batwing mounts installed.




Tubbing wheelwells





Control arm pockets




Eliminating the spare tire well


Mocking up the rear spindles.

Why did you modify the spare tire well? Also, why did you change the geometry of the trailing arms?

I will not have a spare in the car, since I was already tubing the wheel well I cleaned up “the hump”, and I was going to locate the battery there (it’s in the cargo box now). The trailing arms were changed for better travel geometry and adjustability, the final configuration can be seen in the finished pictures.

Makes sense about the tire well then.

Is the C4 rear suspension inherently flawed in stock form? I can understand adjustability, but how did changing it change it for the better? I have the Doug Rippie (I think that was it) trailing arm brackets. I think they spread the body side points out slightly, but the way you did it drastically changed the geometry. Did you plot out the change you made? It seems more like you just wanted to use the stock 3rd gen LCA point

The original Corvette upper trailing arm forward mount point would have been too far inside the cabin to be practical for installation. I am not installing a roll cage as some others have done, and I want to retain the rear seat, or what GM calls a rear seat. The pictures you see were taken in the mock up stage, and the wood trailing arms were used to simulate geometry changes through the suspension cycles. The rear mock up brackets were scrapped after I settled on the final design. The original Camaro forward trailing arm mount was close enough to utilize in the final geometry to have no effect on the caster angles (caster remains zero through +4" of travel). That is also why a fabricated new trailing arms, strut rods, and toe rods.

Thanks for the response. Not criticizing, just wondering. If I ever finish my rear IRS swap, I was going to use the stock mounting points, regardless of interior intrusion, while trying to keep the stock rear seats. I don't see why I can't get the un-modified rear seat back in there with my plan, since the C4 point will essentially still be under the interior panel

You are correct in the point of it will all be contained under the rear kick panel, if memory serves, and it has been a long time since I did this, it came down to retaining the rear seat belt retractor. Mind you, I am not the leading authority on this mod, it’s just how I went about it. Like the saying goes “there is more than one way to skin a cat”.

Got you. I don't care about the rear seat belts, so that won't be an issue for me, I just want it to look stock on the inside

Glad to see someone else is doing this