James, that is an interesting observation. I'd certainly be interested in
anything that you find out. I haven't put a lot of work into suspension
design because I've never really been at a point to do it all over. It is
something I plan to do but not for a few years. I can, however, offer you
two things. One, I have been told that the negative camber a-arms don't
adversely effect tire wear if you are a spirited driver. Two, a whole lot
of things get built but few ever really get designed. I think that the
intention of many of the kits is to move the shocking and springing into the
modern era with coil overs or with tube shocks. I would also guess that
people have shied away from complete redesign because of development cost
versus saleable cost and quantity.
I suspect that one of the problems in making the upper a-arms longer then
the lowers is the shape of the body. I think that in order to make the
upper a-arms substantially longer, they would have to be mounted on the
other side of the inner fender, perhaps on the frame rail. Just a couple of
things off the top of my head.
James Nazarian
71 B tourer
71 BGT V8
85 Dodge Ram
----- Original Message -----
From: James J. <m1garand@speakeasy.net>
To: <mgb-v8@autox.team.net>
Sent: 26 January, 2003 7:25 PM
Subject: test, e-mail notice, and suspension question
> First, to my DC area friends, my e-mail is now m1garand@speakeasy.net
> now that DirecTV has shut down their DSL service.
>
> Now to the group: (and answer me directly if you think it is off-topic
> enough that the group wouldn't be interested) I've been reading up on
> suspension design, primarily to see about options for the back-end, but
> I also started looking at front-end design. What I noticed, is that
> every author that I read said that un-even length, non-parallel a-arms
> are the way to go in nearly evey case (so far, so good, for the MGB),
> however they all suggest that the upper a-arm should be higher at the
> wheel than at the cross-member. The reason being that when a car rolls
> to the right (for example) the wheel on the right side also leans to the
> right, reducing the size of the tire contact patch. With the MGB, as
> that side of the suspension compresses, the upper a-arm travels up
> through it's arc, becoming longer relative to the hub, pushing the top
> of the wheel even further out and reducing the tire contact patch even
> more. If the upper a-arm (in its static position) was angled upward
> from the x-member to the king-pin, then any roll to that side would
> compress the suspension and make the upper arm SHORTER relative to the
> lower arm, and bring the top of the tire back in to reduce the camber
> effect of the roll, and increase the size of the tire contact patch,
> improving handling.
>
> First, I wonder what the MG guys were trying to achieve with that
> design, and second, I've seen at least four new coil-over designs for
> the MGB, where the old a-arms are dismissed with, yet none of them
> change the geometry to "fix" the upper a-arm issue. The car can be
> designed with some built-in static camber to compensate for this, but
> that method increases uneven tire wear on the inside edge. Has anyone
> here used a front-end design that corrects the camber issue? Most of
> the kit/muscle/street-rod crowd have adopted the Mustang II front-end,
> and the parts for this are plentiful and relatively cheap (Including 2"
> dropped spindles). (remember that this car was the same platform as the
> Pinto/Bobcat.......Kaboom!!!!!)
>
> So if anyone has any experience, I'd love to hear from them. Also, if
> anyone is interested in working with me in trying to adapt the mustang
> II front end to the MGB, let me know. When things get a little quieter
> around my house this spring, I want to start taking dimensions off the
> MGB for the front-end and back end and putting them into CAD, and
> playing around with them. TurboCAD is cheap and powerfull. If anyone
> has done something similar, and would like to share their files, please
> let me know, too.
>
> Thanks, and my apollogies to those who don't want to read about
> suspension design.
> James J.
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