Finishing up my MG-B /V6 roadster and am totally confused on rear suspension choices. For starters... I will not be autocrossing or participating in serious track events on any regular basis. I'm simply building a fun high speed cruiser. I've fitted Vicky B tubes on the rear and Spax adjustables on the front with 7/8 sway bar. Tires are 15" mounted on 72 spoke wires.
Given the car will still be perched on leaf springs, do I even need to worry about serious lateral movement in the rear? If so, do I need to consider time/expense of installing either a Panhard bar or a Watts link. Seems like these are for serious racers or folks with coil-over springs that would require really nailing the rearend in place. If so, what do you recommend.... given "doing nothing" wouldn't bother me a bit!
Don B.
You don't need the watts or panhard bar if your not going to be on a track or running serious auto cross. I would install a rear sway bar and that should be enough. Do you have spax on the rears?
Vicky B tubes ?
Victoria British has a kit with some who knows what tube shock conversion.
Just from the fact that you're using wire wheels, I'm guessing your 15" tires will be relatively narrow. No? Therefore, it's unlikely your rear axle will be sliding side-to-side enough for your tires to contact bodywork at the fender lip or at the bump stop mount. Therefore, it's unlikely you really "need" a Panhard rod...
However, you might want one. I put one on my GT and it very noticeably changed the way my car feels. Whether or not it's a good change is a question of preference and perception. I like my Panhard rod a WHOLE LOT, but I don't think they're for everyone. It probably adds a little "noise, vibration and harshness" to my car, but on the other hand I feel the car feels more confident when cornering - even on an ordinary Sunday drive.
I recommend that you get your car running and enjoy it for awhile, and then consider a Panhard rod as a possible upgrade later. You'll probably be able to test drive a few different MGBs at BritishV8 2013 if you want to... that might be a good time to see if you like the characteristic Panhard rod feel. All Panhard rods aren't created equal. They should be as long as feasible. They should be on very stout mounts. In my opinion, if you install one you should probably try to get it as low as you can because the bar's installation height determines the rear suspension's roll center height. Panhard rods should be mounted level at normal ride height.
A Watts linkage is technically better... but it will take extra effort to install one. I can only think of one MGB with a Watts linkage. (Ref: <a href="http://www.britishracecar.com/MichaelZappa-MG-MGB.htm">
Michael Zappa's MGB</a>.)
In the interest of completeness: there are two other options:
(1) You can work to get compliance out of the leafsprings and their mounts. This is typically done by adding extra or tighter clamps along the leafsprings forward of the axle, by replacing rubber bushings with brass front and rear, and by installing heavier duty or reinforced shackles (or by substituting slider blocks for the shackles).
(2) If you look at Lorenz Hassenstein's How It Was Done (or peek under either of Jerry Richards' MGB GT V8 vintage racecars) you'll see that an A-frame may be substituted for the Panhard bar. I think we have some old message board threads about those...
Curtis,
Would it be possible to digitize the Panhard Rod Fabrication (by Gordon Lee Oxford) article in Vol VII?
Don,
I'm thinking a 3/4" sway bar may have been a better match for for you. A 7/8" bar is a bit much for a cruiser & will require a suitable bar in the rear to match.
Thank you all for the input... just what I needed to get started. I think I'll hold on this aspect of the project and see if I can mooch a test ride or two in Omaha to get the feel, before going further.
It's not like I don't have lots of stuff to get finished before Omaha. Better get back out to the garage and lay on that cold concrete... shoulda bought a house in Florida!
Don B.
Throw some cardboard & old carpet under there!
Why rear leaf springs sometimes work. When properly set up, car "rolls" into a turn, outside rear wheel moves back, inside wheel moves forward = crude but effective 4 wheel steering,(cone effect). Don't toss those springs, just yet. Cheers, roverman.