Watts link for first gen camaros

[Twentyover]

.............Im not sure why the wattsl ink would change the need for a sway bar? Roll stiffness is dependent on CG, roll center and spring rates. The panhard and watts could both have the same roll center. therefore the same need for a sway bar.

First, my understanding is that a watts imposes it's roll center loation on a car as a C4L has compliant bushings, leaf springs bend and twist, etc..



If you use the watts to move roll center height close to CG, there will be very little roll, mitigating the need for an antisway bar. Not suggesting this is a desireable design, but say you use a mumford link (similiar in concept to a watts, but can move the roll center below ground on a live axle car) with the RC at ground level, it would require a bigger rear bar because the moment arm between RC and CG is greater.

[The WidowMaker]

Tim, would you know at what point of travel a converged 4 link would bind?

that depends on lots of factors. others have discussed how its possible in roll, but its also possible in bump and rebound. i first realized this when i had poly bushings and took the shocks off the rear on the chevelle. before anything made contact, the rear suspended itself because of the bind.

hard to explain in type, but think about it this way. if your uppers converge at 45*, are 17" in length, have mounts that are narrower at the axle and they are built to be parallel to the ground at ride height we get a few numbers. first, the axle is 12" away from the upper frame mounts and the axle mounts are 24" closer together than the frame mounts (12x2). now, the further we extend the length of the upper control arm, keeping the angle constant, the closer together the axle mounts would need to be. the shorter we make the upper control arm gets us the opposite effect. so, at ride height our arms are parallel to the ground and the axle is the furthest from the upper frame mounts in plan view. as we raise or lower the rear, we decrease the distance between the frame mount and the axle mount requiring that either the frame mounts narrow, the axle mounts widen or the angle changes. since neither of the first two can happen, we rely on bushings to allow the arms to change angle and keep us from binding.

think about this another way. take the same numbers from above and attach your upper control arm to only the frame mount and let the axle end drop. it will hang straight down from the frame. pick the axle end up until its parallel to the ground and the axle end will move inboard 12". that requires compliance from the bushings.

[AMC Racer]

Double-checked models of 3-link, 4 Bar and Triangulated (or converging) 4-link:
- zero compliance model (zero deformation permitted in any links, chassis, etc.)
- spherical joints in link ends and mating chassis and axle points (links are free to swivel but no translation allowed)

4-Bar with Watts:
- parallel, equal length links
- will roll freely when watts links are parallel to each other and perpendicular to the watts crank
- binds in combined bump & roll when watts roll centre moves away from 4-bar centre
- links do not remain parallel in roll, but do keep symmetry
- unequal length links or non-parallel links will not roll freely without compliance (links need to translate as well as swivel)

Triangulated 4-link (converging 4-link):
- tested converging uppers, converging lowers, both converging
- all behave similarly
- full freedom in roll & jounce - ZERO BIND (contrary to conventional wisdom)
- requires swivel joints in links for total freedom in roll and jounce

3-Link with Watts:
- full freedom in roll within normal limits, ie. normal limits of Watts

In all cases, using bushings instead of swivels (heims or similar) causes restraint so bind. Link length and geometry is a significant factor in the amount of swivel required at the link ends. Typical OEM T4L geometries can require more swiveling of the links for free movement, so with bushings may bind at low roll angles or limited bump/droop (likely the reason the T4L has the reputation for binding) ... however, kinematically the T4L is free in roll, bump and combined movements when links have swivels. Rigid urethane bushings are likely a poor choice.

Hope this helps.

Triangulated 4-link in roll video:
http://s41.photobucket.com/albums/e2...bindinroll.mp4

4-Bar (Parallel, equal length 4-link with Watts) in roll video:
http://s41.photobucket.com/albums/e2...rollnobump.mp4

4-Bar (Parallel, equal length 4-link with Watts) in combined bump & roll - note side movement when link is removed (suspension was in bind):
http://s41.photobucket.com/albums/e2...r4-barbump.mp4

[The WidowMaker]

binds in bump or droop when watts roll centre moves away from 4-bar centre

im not sure i follow you here. is this bump or droop with roll as well? if so, your model may be reporting binding if it does not not allow for axle migration. there is side to side movement with both style watts links. there is no binding with with regular bump and jounce.

[AMC Racer]

Sorry, yes ... the "bump" shown is combined bump and roll. With pure bump or droop or pure roll, the 4-Bar & Watts linkage moves freely ... but combined bump and roll needs compliance. Updated post to clarify.
Thanks!

[JRouche]

Umm? Can I pipe in. I have used the pan hard bar in my car. It was an art morrison setup. Looked to be more for strait line driving. Like 1/4 mile cars, or pro-street cars.

Not good for street driving. Its a proper four link setup. Plenty of bind. It would lossen up the jamb nuts on the links just to get more travel. Not good.

So I swapped out the stainless steel (nice) rod ends that were poly ends for some decent qa1 spherical ends. Capped them off with some covers and Im hoping they will survive.

Now I can get a good 5-6* of body rotation and the ends dont bind. It sucks to have to go through this amount of work and money. But its my fault. Back in the mid 90s I didnt know what the plan was, and really, pro-street cars were the ticket. Now that I know better (and have more options) handling is higher on the ticket. I have a watts link. Along with it and the new rod ends and some decent roll bars the car is scary fast in the turns.

Its nice to drive AROUND a newer honda when Im on the outside lane. Kinda funny seeing a 1962 nova driving around a new light honda. Its fun. JR

[SIK02SS]

problem with putting covers/boots over rod ends, is once dirt and grime finds its way into them (which it will), it's stuck in them.

also, rod ends have different strengths, do you know what yours are? Hopefully XMR or better..and over time rod ends wear out, especially on street cars with high use, meaning they'll get very loud (clunky) and need replacing...but yes, they are bind free if installed properly

another bind free and quiet option are roto joints. UMI sells roto joint items..

[NewSpin]

I know this thread is a bit old, but i'm curious about the Watt's link kit for my '71 Nova
and a friend is curious for his '75
what was the final conclusion? Was is worth it?
I recently sold a Chassisworks triangulated 4-link I was never able to install, but I'd be open to keeping leafs and adding a Watt's link kit if it will really do the job.

[BMR Sales]

I know this thread is a bit old, but i'm curious about the Watt's link kit for my '71 Nova
and a friend is curious for his '75
what was the final conclusion? Was is worth it?
I recently sold a Chassisworks triangulated 4-link I was never able to install, but I'd be open to keeping leafs and adding a Watt's link kit if it will really do the job.

I don't think there is much benefit of a Watt's Link unless you get rid of the Leafs.

We make a Torque Arm w/ Watts Link for Novas & Camaros

Here the Watts Link that we just put in my '73 Camaro



Here's how a Watts Link works

[F-Body International]

I know this thread is a bit old, but i'm curious about the Watt's link kit for my '71 Nova
and a friend is curious for his '75
what was the final conclusion? Was is worth it?
I recently sold a Chassisworks triangulated 4-link I was never able to install, but I'd be open to keeping leafs and adding a Watt's link kit if it will really do the job.

Update to heavy duty leaf shackles/bushings and you should have less lateral flex.

[NewSpin]

I've already got heavier multi-leafs on my car, I knew how it worked I was just wondering how this particular kit worked out for the OP.
BMR that looks pretty snazzy, is it bolt-on?

[F-Body International]

I've already got heavier multi-leafs on my car, I knew how it worked I was just wondering how this particular kit worked out for the OP.
BMR that looks pretty snazzy, is it bolt-on?

Yes, their kit is bolt-on. Most other link suspension kits require welding at some point.

[BMR Sales]

I've already got heavier multi-leafs on my car, I knew how it worked I was just wondering how this particular kit worked out for the OP.
BMR that looks pretty snazzy, is it bolt-on?

Yes, that is all Bolt-On