3-Link

[Boostin1989]

I'm getting ready to get serious about building an LS powered G-Machine Regal but it'll mostly be a street car.. Has anyone ever put a 3-link rear suspension in one of these cars? I'm currently doing some layout work in CAD to see if there are gains to be had over the factory 4-link. If I go this route I plan to use a watt's link. The back seat will either have to be removed or hollowed out to make room for the center upper link. Does anyone have any thoughts, opinions or suggestions about this idea?

 

[charlief1]

GM did it back in the 80's. Remember the GNX? You don't have to have it at the top afterall.

 

[Boostin1989]

Doesn't the GNX have a torque arm, like a mini F-body setup?

 

[charlief1]

Doesn't the GNX have a torque arm, like a mini F-body setup?

It's still a 3 link even though one is solid mounted to the axle. The 63 Impalla also had exactly what you're asking about and it was adjustable. I rebuilt a 62 Biscayne's rear suspension and it had the same thing. The mount for the upper arm used shims under it to move it closer or further back.

 

[Turbo6inKY]

I'm getting ready to get serious about building an LS powered G-Machine Regal but it'll mostly be a street car.. Has anyone ever put a 3-link rear suspension in one of these cars? I'm currently doing some layout work in CAD to see if there are gains to be had over the factory 4-link. If I go this route I plan to use a watt's link. The back seat will either have to be removed or hollowed out to make room for the center upper link. Does anyone have any thoughts, opinions or suggestions about this idea?

What are you hoping to accomplish? Better drag launches? Better corner carving?

I can't find my spreadsheet, but I did all the math a few years ago, and to do a 3 link requires more than modifying the back seat. The outer control arms also have to be relocated and lengthened to get the job done. I quickly abandoned the endeavor.

A Fayes Watts link with the stock control arm configuration (use rubber bushings in the control arms) will get you 80% where you want to be without cutting the car up if your aim is handling. It gets rid of the rear steer and relocates the roll center and makes the car much more predictable. It can't help your instance center and provides no anti-squat, though. That's the 20% you'd get from a properly done 3 link.

The GNX setup was great for drag racing, but the torque arm is too short and it still binds in roll.

 

[Boostin1989]

What are you hoping to accomplish? Better drag launches? Better corner carving?

I can't find my spreadsheet, but I did all the math a few years ago, and to do a 3 link requires more than modifying the back seat. The outer control arms also have to be relocated and lengthened to get the job done. I quickly abandoned the endeavor.

A Fayes Watts link with the stock control arm configuration (use rubber bushings in the control arms) will get you 80% where you want to be without cutting the car up if your aim is handling. It gets rid of the rear steer and relocates the roll center and makes the car much more predictable. It can't help your instance center and provides no anti-squat, though. That's the 20% you'd get from a properly done 3 link.

The GNX setup was great for drag racing, but the torque arm is too short and it still binds in roll.

Thanks for the response. I was planning on moving the lower control arm locations but that seemed easy compared to the fabrication required for the top link. I'm putting together a Ford 9" so I'm already making special brackets etc.

I know the watt's link locates the rear roll center at the pivot of the linkage. I've never heard that it eliminates roll steer. My understanding is that roll steer is a function of the control arm configuration and length. I noticed that the Fayes site says it prevents the axle from "dog tracking" as they put it but I think what they're really getting at is that it positively locates the rear end under the car to keep it from deflecting side to side.

I'd be interested in that spreadsheet if you find it and are willing to share. Once I get all my info together for the work I'm doing in CAD I'll post it, though it may be a little while.

 

[dsapper]

fyi the fays watts link and a ford 9" are a total pain in the ass to make work together, thats what I currently have. There isn't enough room for the brackets to attach to the rear. Its quite a bit of fabrication to modify it