Re: [DML] Front Suspension Mod's

["Walter Coe" <Whalt@xxxx>]

> why did Bern use such thick material to make them
> stronger. Why isn't he concerned about un-sprung weight. Heavier arms will
> change the ride handling. The arms were made lightweight But cheap for a
> reason.

I was able to look at Byrne's custom lower control arm in person. He did a
very nice job. I suggested that he add a plate to part of the bottom to box
it in. (You still need room to get the shock absorber inside.) He agreed
that was a good idea and would probably start making them that way. Of
course, this would make it heavier still. Problems associated with extra
weight never occurred to me before, and I really don't think it is
significant enough to worry about for two reasons. 1) It's not that much
weight in proportion to the total un-sprung weight. 2) The "lever arm" of
the control arm's mass is small compared to the "lever arm" of everything
else hanging on the suspension. In other words, the closer the mass is to
the pivot point, the less distance it travels and the less a change in
momentum affects the suspension response time. For example, in one hand
hold the entire wheel assembly (if you can) and in the other hand hold the
lower control arm. Then keep in mind that the extra mass of a heavy duty
control arm is closer to the frame than the rest of the assembly and
therefore imposes less inertia. (Wow, I'm really having to stretch my
fingers to type out these technical words. :) By the way, has anyone
compared the mass of the aftermarket lowered springs compared to the OEM?
My PJ Grady springs have more coils but are shorter. I bet they weigh more.

I am not up on what the strengths of various alloys are (yet). So I am
curious that even though you are using a high strength alloy, are your welds
going to be comparably as strong? Also, I'm curious to know how you are
going to make the seat for the spring and the bushings. Byrne's spring seat
is a case of overkill. It was cut on a lathe in order to make a lip deep
enough to keep the spring from slipping off. It was also made extra thick &
heavy. The bushing for the swaybar stud was likewise cut on a lathe. So
how are you making these sections? Pictures! Show us pictures! :)
Remember that when you re-seat the spring to be sure that the tapered end of
the last coil is resting on the center of the control arm and not over the
side. The next time I have my suspension apart, I would like to put a thin
soft ring between the spring & seat to stop the squeaks. I greased it
before, but that didn't help much. I'm thinking maybe some teflon sheet,
paper gasket material or maybe even leather. Suggestions anyone?

When I installed my lowered front springs, I was going to replace my lower
control arms at the same time with what PJ Grady was in the process of
making. At the time he was working on a prototype pair that he was going to
sell me, but time ran out. I need to put the car back together to make it
to the SEDOC show last September. So I ended up using my OEM arms. I'll
forward to you what I learned from him in the process of discussing this
deal: He originally had some arms machined from billet aluminum but never
used them. He didn't get too detailed with his reasons why except that they
weren't quite good enough to meet his standards. His next prototype was
made of steel. I assume that by now he has finished his first batch of 50
and has been selling them to the public already. Does anyone know his
progress?

Walt Tampa, FL