<VV> Cocktail Shakers

[Tony Underwood]

At 04:17 hours 06/03/2005, Padgett wrote:

>>They're flexible enough that the General thought they needed the dampers in
>>the corners.
>
>Actually so did the Camaros, Firebirds,


...because these cars (F  body) were direct take-offs of the Z body (Vair) 
platform and suffered the same axial flex problem.


>and 90-91 Reatta convertibles.   Dampers are more to stop cowl shake than 
>any body flex.

Results in the same thing in this instance.   The body twists in the middle 
between the A and B pillars where the floor is all that connects the front 
and rear halves of the car.   I've also noticed that many late ragtops with 
some miles on them tend to suffer cracks in the A and B pillar joints.  MIG 
welder time...   As I mentioned earlier, the body certainly will flex if 
the car traverses uneven surfaces; it's evident in the fit of the doors if 
the car is even parked on an uneven surface... unless it has a roll bar 
tied to various points etc.   Early ragtops have a much stiffer floor... 
and they get it by sacrificing floorboard space.    Check out the 
differences between early ragtop rockers and late ragtop rockers.

>Cars with short wheelbases and unibodies are more affected than ones with 
>real frames.


Then again, Corvairs have rather long wheelbases for such a small 
car.    The FC/Vans had shorter wheel bases as did just about every other 
car GM made that was less than 180 inches long.    Add to this the rather 
odd weight distribution...  a Corvair is always trying to hump up in the 
middle rather than sag like most other ragtops.   Unibody doesn't help much 
when there's no roof... while it makes coupes and sedans more rigid.


>Removed mine early on (are quite heavy) and never noticed any particular 
>problems.


They're stopgap devices.   Most times they're not doing much of anything 
but if you should indulge a stretch of road with the right lumps at the 
right speed, harmonic resonances will really start shaking the car.   The 
dampers help quiet most of this.   I've abused a couple of late ragtops via 
a stretch of tanktrap road close by, with and without the dampers.   Under 
the right road conditions, they certainly do make a difference.

I *did* take out the rear dampers in my ragtop, left the fronts in 
place.   The reasoning is that the front is likely to be doing the most 
dancing in this instance what with softer shocks and springs; the rear has 
shocks from Hell.   I noticed no difference in the car's behavior after 
removing the back dampers with the stiff shocks.    Without the dampers and 
the stock shocks, the car would also tend to "scamper" around as if it were 
tail-happy if you ran it over rougher roads and pressed it through the 
corners.   The rear does have some negative camber cranked in...  might 
have made some differences.   It doesn't lean much  but it does ride kinda 
rough in back.   Some of the logic/reasoning with this concept doesn't ring 
quite true for some reason... but this is what it works out to, so I left 
the rear dampers out.


tony..