Mark, my son's 55 1st Series 1/2-ton (with Malibu front clip) weighs 3400
lbs w/o driver. My 56 TF Cameo weighs 3570 lbs w/o driver and less than a
1/4 tank of gas. We weighed them both at the local landfill. As for the
weight distribution, I can't help there. But the issue of spring rates is
something I have been working on for some time.
I have a customized IFS on my 56. The original frame was retained - tubular
upper a-arms, 1x3 lower control arms, and positioning struts were added
along with Carrera coilovers, Chevelle spindles and the Chevelle sway bar.
This is essentially the same type of suspension oval track and dirt racers
run (sans sway bar). We also added a MII Power R&P steering box. When the
suspension was first done it was setup with 550 lbs springs. It was very
stiff. I tried a set of 450 lb springs, naively thinking that surely a 100
lb differential would make all the difference in the world with ride
quality - wrong! The ride softened a bit but it was still way too stiff.
To make a long story short, many years went by with that setup but I have
been addressing the ride quality issue again just recently. Between my son
(who has been active with the SAE Formula Car competition at college) and a
local dirt track racer I have discovered a few things.
It is now apparent that when the original IFS was designed (or constructed -
I'm not sure how much design went into the thought process) in the mid to
late 80's, stiff springs and stiff shock valving was the way oval track dirt
cars were setup. Today, that is not the case. Drivers want to feel their
suspension and understand exactly how their vehicle is performing and be
right on the edge of being out of control. Consequently, much softer spring
rates and dual shock valving are used to allow the vehicle to react. So I
acquired a set of 300 lb springs and was again disappointed in the ride
quality - it was noticeably better than the 450 springs but it just wasn't
right. When we checked the shock valving in my coilovers I discovered they
were a "7" (based on Carrera's scale of 1-9 then) which are considered
x-stiff. This would appear to be the problem I have been having all along
with ride quality - at least we think it is. I am waiting to receive
another set of shocks that are valved softer and see how they react.
Interestingly, I contacted Carrera tech support and their Street Rod guy
recommended 450-500 lb springs for a vehicle weight of 2800-3000 lbs. At
the time, I thought he was crazy. It may be that with the softer valving
the 450 lb springs will be ok. In retrospect he may have been correct - I
won't know until I try the new shocks.
I guess my point of all this is be careful what combination you put together
and understand all the components. Shock and coil spring travel length,
shock valving, and spring rate all need to be considered for your particular
application at the ride height you desire. After you have the ride height
and shock/spring combination, you may need to re-address caster and camber
issues.
Bob Welch
Bartlesville, OK
'56 Cameo
'55 Belair
----- Original Message -----
From: "Mark Self" <markself@discover.net>
To: "Oletrucks list" <oletrucks@autox.team.net>
Sent: Wednesday, July 12, 2000 08:57 AM
Subject: [oletrucks] 3100 AD weight - spring rate
> Can any of you guys tell me the weight of a 3100 AD. I looked in the
manual
> and couldn't find it. The ID plate on the drivers side door post says
GVWR
> 4800 lbs. Since this is a half ton, does that mean that the truck empty
> weioghs 3800 lbs.?
>
> Also do any of you knopw what the front to rear weight distribution is?
I'm
> trying to figure my spring rate for the front coils in the IFS.
>
> ====================
> Mark Self
> Redlands, CA
> '55 1st 5-window 3100
> "Sentimental Journey"
> ====================
>
>
> oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
>
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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