C4s not rigid enough?
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Navigator
Joined: Jul 2002
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From: Taunton MA
C4s not rigid enough?
I read an article a couple days ago, that said how the c4 was never intended to a be a targa top, and that the change was made at the last minute, leaving the engineers little time to compensate for the lack of rigidity.
so, anyone have first hand experience stiffening up the frame? like with braces for the piece that conects the transmission and the rear end? or maybe that ugly new bar type thing that fits into the roof?
[Modified by sspazm, 6:56 AM 7/19/2002]
so, anyone have first hand experience stiffening up the frame? like with braces for the piece that conects the transmission and the rear end? or maybe that ugly new bar type thing that fits into the roof?
[Modified by sspazm, 6:56 AM 7/19/2002]
Burning Brakes
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From: Costa Mesa CA
Re: C4s not rigid enough? (sspazm)
My '87 is stiffer than my '84 Camaro was. You can tell how bad it is by how much the door is out of alignment when you jack up one corner of the car. You could install the "X" member that's stiffens the convertable if it bothers you.
BIG JIM (Hey, how come I don't see the specs on my car when I post like everyone else?)
BIG JIM (Hey, how come I don't see the specs on my car when I post like everyone else?)
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From: Dallas Tx
Re: C4s not rigid enough? (sspazm)
The Vette chassis was stiffened for the convertible in 1986. The same reinforcements were added to the ZR-1 chassis. According to Chevy, they included:
--a bigger bar between the frame rails forward of the engine
-- bigger K-braces connecting the frame rails to the under-engine crossmember
-- a reinforced front torque box
-- a reinforced steering column, instrument-panel beam, and cowl bracket
-- spring-loaded wedge pins in the doors
--a number-three bar across the top of the rear torque box from rail to rail behind seats;
-- a double-panel seatback riser
-- an X-brace stretching from the door-hinge pillars to a point opposite the rear torque box
Note that the ZR-1 was heavier than the coupe, despite an aluminum block. Much of that weight was probably in the chassis reinforcements.
Other than the X-brace, I don't know that the other chassis reinforcements are available or do-able on a coupe. Does anyone else have any experience here?
The obvious chassis stiffening ideas are
1) a Roll Bar (preferably) or harness bar
2) a front camber brace
3) the X-Brace from the convertible
4) the targa brace if the top is off.
Whether with these mods the coupe (or for that matter a ZR-1) is as stiff as a stock C5, I don't know.
--a bigger bar between the frame rails forward of the engine
-- bigger K-braces connecting the frame rails to the under-engine crossmember
-- a reinforced front torque box
-- a reinforced steering column, instrument-panel beam, and cowl bracket
-- spring-loaded wedge pins in the doors
--a number-three bar across the top of the rear torque box from rail to rail behind seats;
-- a double-panel seatback riser
-- an X-brace stretching from the door-hinge pillars to a point opposite the rear torque box
Note that the ZR-1 was heavier than the coupe, despite an aluminum block. Much of that weight was probably in the chassis reinforcements.
Other than the X-brace, I don't know that the other chassis reinforcements are available or do-able on a coupe. Does anyone else have any experience here?
The obvious chassis stiffening ideas are
1) a Roll Bar (preferably) or harness bar
2) a front camber brace
3) the X-Brace from the convertible
4) the targa brace if the top is off.
Whether with these mods the coupe (or for that matter a ZR-1) is as stiff as a stock C5, I don't know.
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