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View Full Version : Any Opinions/info on this 3link setup.



TurboLark
07-05-2007, 12:53 PM
Has been used in offroad stuff for a while. The upper link is actually an A with a rod end or uniball at the axle mounting point. There was no need to use a panhard or watts with this, as the upper link did that job.
Has this been tried? Drawbacks?

Thanks.
Phil

jerome
07-05-2007, 01:15 PM
upper wishbone needs to be beefy.
roll center not as adjustable as panhard
if lower links converge, roll axis is drawn from upper axle mount to convergence point of lower links. That means you can tune for neutral or understeer under roll, while still maintaining good antisquat and side view swing arm length, but this is true of any converging 3 link with a lateral restraint, you are just moving the lateral restraint to a wishbone. I don't see any significant advantages other than ease of fabrication if you make the top of the "A" towards the front of the car. This way you weld the mounts for the legs of the A on the axle

Jerome

ProTouring442
07-05-2007, 02:22 PM
Could this design be used to rectify some of the problems with the converging link GM A-Body rear suspension?

Shiny Side Up!
Bill

MuscleRodz
07-05-2007, 02:54 PM
Could this design be used to rectify some of the problems with the converging link GM A-Body rear suspension?

Shiny Side Up!
BillAlready been thought of. The issue is the GM rear doesn't provide a very good upper mounting location. You would have to use a 9 inch rear with a very beefy ball type rod end to minimize binding in roll.

TurboLark
07-05-2007, 03:49 PM
I plan to use a Ford 9" for this car, so fabrication on the housing is easy. My idea was to try to make the suspension as bind free as possible, have good anti squat(for the dragstrip mainly), and get rid of the mess that a PH bar or watts makes at the backside of the axle(cleaner, streamlined look as opposed to a race car look). I would put bushings at the mounting points to the frame(legs of the A) and a uniball with a 3/4-1" thru bolt at the axle. The front mounts could have a few different settings for tuning if really needed.

Where would the rollcenter height be located on something like this?
Thanks for the info sofar.

boodlefoof
07-06-2007, 11:58 AM
Might want to consider the Satchell link. That will put RCH below the axle housing and is very similar to what you've shown already. I have built a Satchell link suspension for my Datsun 240-Z project, although it isn't on the road yet. Pics are in the link.

http://www.geocities.com/boodlefoof/Project_Racer-Zsuspension6.html

ProTouring442
07-06-2007, 12:50 PM
Already been thought of. The issue is the GM rear doesn't provide a very good upper mounting location. You would have to use a 9 inch rear with a very beefy ball type rod end to minimize binding in roll.


Hmmm... and I already have the 9inch.

Like I need something else to change!
Shiny Side Up!
Bill

ProTour69GTO
07-06-2007, 01:16 PM
Already been thought of. The issue is the GM rear doesn't provide a very good upper mounting location. You would have to use a 9 inch rear with a very beefy ball type rod end to minimize binding in roll.

What about cutting out what getts in the way and then ad whats needed?

Marcus SC&C
07-06-2007, 01:47 PM
The roll center ends up exactly at the pivot axis of the upper A arm on top of the rear axle. It`s still very high but at least it`s a little more stable than a factory C4L. You`re right about the offroad connection,it`s exactly the rear suspension used on the rear of LandRovers,Isuzu Trooper IIs and some 4WD rock crawling suspensions by Fabtech etc. I dabble some in offroad and have done some consulting/designing for offroad suspensions. It works there because it articulates pretty well and the high roll center is a handy thing on a truck with 44" tires. I kicked around the idea of retrofitting an upper wishbone to G and A body cars but came to the conclusion that the juice wasn`t worth the squeezing. Mark SC&C

MuscleRodz
07-06-2007, 05:32 PM
the juice wasn`t worth the squeezing. Mark SC&CLOL! you and your movie quote...