View Full Version : Advice for 4-link upgrades
1962nova
11-12-2009, 04:50 PM
My 62 Nova has a Total Cost Involved bolt in 4-link. It is a parallel 4 link set up with a diagonal track bar. The 4-link bars uses a poly bushing at each end.
This car is mostly a street car, but I would like to make it a well balanced car, a little autocross, drag and fun driving around the curves.
I plan on getting rid of the track bar and putting on a panhard bar. I have been looking at Curries Johnny Joints (or something similar) to replace the poly bushings. Would this be a good upgrade to limit the 4-link from binding? If so, should I replace all the poly bushings with the Johnny Joints?
Any advice on how to improve my set-up would be appreciated.
Here is a pic (not of my car) of how the suspension is set up.....
https://static1.pt-content.com/images/noimg.gif
BillyShope
11-12-2009, 05:57 PM
I wouldn't say this is a very good setup for both dragracing and autocross. I'm certain you realize that you'll always have link bind in a corner if the upper and lower links are not parallel in side view. And, of course, there aren't enough adjustment holes at the front.
I'd suggest you use some 4link software (there's a free spreadsheet at my site) and use an asymmetric adjustment (also at my site) to provide about 70% antisquat (any more and you might have wheel hop problems during braking) and dynamic cancellation of the driveshaft torque (which tends to unload the right rear during forward acceleration). Shoot for instant center locations as far forward as your adjustment options provide (to minimize linkage bind). This should provide a pretty good compromise setup.
http://www.racetec.cc/shope
raf0419
11-12-2009, 06:30 PM
Great question. Keep in mind I'm by no means an expert in this arena, but I know 4wheeler guys who swear by Johnny Joints and Heim joints to maximize their articulation. Assuming you had other factors corrected as Billy points out, it seems logical the Johnny joints would help.
DSE engineered their 4 link setup to have some rotation..... I'm curious to see what orthers think.
Of course you could be a trailblazer - Give it a go and let us know!
BillyShope
11-13-2009, 05:25 AM
DSE engineered their 4 link setup to have some rotation..... I'm curious to see what orthers think.
I took a look at the patent. First of all, it's amazing that the patent office will allow such broad claims! It would appear that all other 4link manufacturers are infringing.
It would appear that the patent merely allows the Panhard and upper and lower links to rotate (swivel) about their respective long axes. In other words, I found absolutely nothing which would eliminate the primary 4link bind, which is caused by the fact that...in a corner...one end of the axle housing is rotating (or trying to, at least) clockwise and the other end is rotating counterclockwise.
A better solution for a street/strip/autocross car (if you absolutely need that fourth link) would be to take something equivalent to the Art Morrison 4bar and fabricate additional brackets to allow angular adjustment while maintaining the parallelism of upper and lower links. And, of course, an even better solution is an asymmetric 3link.
http://www.racetec.cc/shope
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