Hi All,
I've never had a Bricklin apart, but me and my buddy converted his '68
Corvette coupe into an SCCA 'A' Prod. racer. So, after reviewing John B's
pictures and drawings, my .02 worth: (flame suit on)
A Bricklin is a so-so adapted 'Vette design which is itself a poor design.
Stiffen up the chassis as best you can with gussets to strengthen the joint
between the center section / rear portion. Assuming all birdcages are made
from the same design / gage stampings, it's not nearly strong enough to
sufficiently stiffen the chassis by itself. I believe you will destroy the
body panels from the extra flexing of the birdcage if you remove the isolation
washers. The amount of extra tube bracing front and rear required to make the
cage sufficiently rigid will cause other parts / system installation
headaches. If there's room, run a hoop from the frame in front of the cage up,
across in front of the firewall, and back down on the other side. Run another
tube attached at the bend to the tower, then down to the front of the frame.
Tie the two together with a cross piece (this could be bolted in instead with
the appropriate brackets). Gusset all joints. This, with the removable tower
brace should handle street tire loads. Make channel braces to effect 'X' frame
bracing in the center portion to tie the four corners to the existing cross
brace. I doubt the tube from the cage to the mounting bolt will do much
without triangulation. Voila', you now have a late model Cobra replica
chassis. With a well tuned suspension and the right wheel / tire combo, .95+g
on a 200 ft skid pad is a realistic goal. Body panels will probably crack and
the ride will be stiff, especially if you go the urethane bushing route. With
std. bushings, etc., .80-.85g. That's a quantum leap over a stockers .67-.68g.
A Watts linkage is essential.
If performance is everything, have Riley and Scott weld up a Trans-Am chassis
adapted for gullwing doors.
Have fun,
GM
Hi everybody.
I've been doing some thinking about the stiffness of the
Bricklin's chassis (which I've been told is less than adequate,
and looking at it I don't have a hard time believing that).
The chassis is almost all in one plane, which would explain
why it tends to flex torsionally and longitudinally, although
laterally it should be OK. The birdcage and the rest of
the body should help this somewhat, and I'm assuming that
they're intended to, but the rubber pucks between the body
and the frame make me wonder if they can actually help.
If the chassis wants to flex, and the rubber between it and
the (supposedly supportive) body/birdcage is allowed to
deform, how can the b/b exert a force to prevent that
flexing?
I'm a long way from putting the body back on the frame,
but I'm wondering if it would make sense to replace the rubber
mounts with something solid (or at least, more solid than
rubber). I've been thinking that it might be a good move
to go with some kind of solid mounts, and extend the
birdcage into more of a roll cage by welding in some struts
from the rear bulkhead of the cage to two of the mounting
bolts in the rear cargo area.
Am I right in being worried about chassis flex? I am planning
on having a custom frame built, so I might be able to improve
on stock somewhat, but I don't want to go _too_ wild when it's
other people's time and my money ;) It is my intention to
build the 351 to maybe twice the factory's 175hp, and to
go with poly bushings in the suspension, so that frame's
going to see greater stress than a bone-stock car's would.
(BTW - a brace across the front shock towers is already on
the to-do list)
Has anyone tried replacing the rubber with something stiffer?
It seems like NVH might be increased, but look at all of the
unibody cars where the body and frame are a single integrated
unit - transmission of vibration into the cockpit doesn't seem
to be a concern or a problem there...
Interested in any thoughts,
--
Phil Martin pmartin@isgtec.com
"I think I'm dumb" - Kurt Cobain, 'Dumb'
"I'm retarded" - Chris Farley, 'Tommy Boy'
"What was I thinking?" - Phil Martin, every day.
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