i heard they had a sale on sfc's. asked if they would fit a vert and this is what they said
"Nope sorry. Convertible f-bodies already have factory subframe connectors which cancel out most of the flimsiness of a vert so I wouldn't even worry about it. "

 

yea our verts do have extra bracing.....but if you call a flimsy piece of stamped metal a brace then someone's pulling your chain. Get your hands on some kenny brown double diamond subframes and you will be a happy man.

-brian

 

Granatelli sells what Granatelli has, and of course you
only need that. Yeah.

There's nothing wrong with the stamped reinforcement
itself. But there is no triangulation to make the floor
pan torsionally stiff, you can't expect a straight rail
to do it. I've lifted one corner of full frame cars like
a GM A-body, stout boxed convertible frame and you
still can get a couple of inches of flex on a straight
H frame. Just by hand against the weight of the
piece, forget actual cornering loads.

You want the body to be stiff, you have to pick up
the rear wall behind the seat (using the LCA attach
points if you want it under-car) and brace that to
the front firewall. Or close as you can get. Those are
your only vertical-plane, cross-body rigid features on
a 'vert. For torsional stiffness you have to go across
the car diagonally. The double diamonds do that, only
in segments tied together at the tunnel brace point.

Making your own out of box and flat stock isn't too
farfetched a project if you have any welding ability.
It looks to me like it needn't be quite as many sticks
as the KBDD design uses either, given the factory
bracing is there and is in fact stiff enough in its
intended (fore-aft, vertical plane load) direction. You
don't see these cars sagging at the doorsill. It's the
torsional flex that you want to control and that, any
straight-stick parallel pair is helpless against pretty
much. Whigh is why the bolt-on, non-triangulated
SFCs are a bad joke on convertibles.

My notion is to make a knockdown bracing that bolts
LCA mounts to trans crossmember & that, to K-member.
Think this can stiffen things up a fair bit without welds
(hate the idea of breaching the finish with welds,
unibody rust points on a car I consider a "keeper").
And removable without grinding, for service or whatever,
is a bonus in my book.

 

I truely agree with ya here. But when I bought my kbdd's 5 years ago, there wasn't any bolt-ons availiabe that had a double diamond design

 

what do people like me do who has to remove the stock SFC because of the dual exhaust. their is no possible way to have the stock on with the TSP dual exhaust