highhilleer

That should settle any arguments about the evilness of air shocks/load levelers in classic mustangs. Thanks

andrewmp6

if you want a 4 link id talk to http://www.martzchassis.net/page3.htm

73 Sportroof

The 4 link will have to wait. I haven't driven this since '99 and I am wanting to drive it for a while before I do any more major things to it.

Glad to be of help with the pixs.

Norm Peterson

I would use a 4-link if moderately serious drag racing was going to be in the car's future, but not for a daily driver or for any activities involving hard cornering.

If you're determined to swap out the leaves, give some thought to either a torque arm or 3-link suspension. Either of those will be better at drag racing than a drag racing oriented 4-link will ever be at cornering. The Fox/SN95 guys are swapping to those arrangements for a reason, and the engineers at GM (3rd/4th gen F-body) and Ford (S197 Mustang) didn't break away from the basic designs of the previous generations of those cars just for the sake of change.

Norm

andrewmp6

norm it depends on which 4 links theres 3 different ones mines a heidt 4 bar style handles better then it did with the leafs. the art morrison tri 5 chevy frame made a tri 5 pulled a .94g on the skidpad with a triangulated 4 bar set up.

Norm Peterson

Any parallel 4-link, which also requires a PHB or other means of laterally locating the axle, is drag strip oriented. Period. It has too many links to freely permit the motions required by cornering (roll) plus normal vertical suspension motion (you have 5, as you have to count the PHB as a link). But you only need 4, since that's enough to control the four possible axle movements that you don't want more than tiny bits of (axle moving straight back or sideways, large amounts of either axle steering or pinion angle change). The extra link in a 4-link with PHB is any one of the 4 longitudinal ones, and it causes the axle to act like a huge rear sta-bar (aka antiroll or sway bar). It may give the impression of "better handling" under moderate conditions because the axle is so stiff that very little roll is developed and understeer is reduced even at low levels of cornering g's. But that's way too stiff, especially if you want to be able to lead the throttle down while you're exiting the corner (but still in it). Handling is more than just flat cornering.

The triangulated 4-link at least gets rid of the "extra" link, but has a few deficiencies of its own that take it off the top shelf of handling choices. Without some bushing compliance (flexibility, "squishiness", whatever) it wouldn't move at all with the usual cylindrical bushings. Rod ends solve that issue, but aren't all that durable. And the axle may take some strange paths during combinations of bump and roll.

The triangulated 4-link suspension (you may also see it described as"converging 4-link") is what all the serious-about-cornering Fox/SN95 guys are swapping out. It's fine for moderate or slightly harder driving, but involves too many compromises when handling/cornering takes absolute priority over all else. Far clumsier that necessary in a slalom, for example, and it may snap-oversteer up around the limits of tire grip on you. I have the same sort of mess underneath the '79 Malibu that I autocrossed and tinkered with for a few years (how's that for a long and sneaky way of saying BTDT).

What I see in AM's rear suspension kit is a lower geometric roll center than you get with a Fox/SN95/GM intermediate, plus a rear sta-bar to bring the lateralload transfer back into balance. So it'll slalom better than with a higher geoRC, but other geometric issues remain.

Handling is more than lateral g's. That is part of it, but skidpad results are more a measure of how much grip you have than how well it can be used. My own guess is that 0.94g in that shoebox on a flat skidpad is as much a function of its non-stock front suspension and wheel/tire package than on anything done to the rear (I sort of know the guy who did at least the front suspension on that car). After tinkering, my 3450# '79 was nearly that good on only225/60 Firestone SZ50EP's on 15 x 8.5 wheels.

Somewhat aside, AM is now listing a 3-link, and while it may not generate much or even any more lateral acceleration than 0.94g in an otherwise identical '55 it will drive (hard, of course) better.

Norm

andrewmp6

the front front suspension on it is c5 corvette but still .94g is high for something that heavy the c6 corvette is a .98g. i have seen alot of road racers start to use a 3 link with a wishbone sliding upper. or a normal 3 link with a watts link to it.but ill stick to the old tried and true ways i know.