Pros & Cons of Chevelle 4 link

[MuscleRodz]

I have been planning for a while now to use a Chevelle 12 bolt under the rear of my 68 Camaro. I am now ready to start fabricating and put it in the car. I like it it for simple packaging, and minimal fabrication.
However, and as always, I second guess everything I do. I am concerned with dramatic pinion angle changes with the short upper arms, and if I run spherical upper links to eliminate binding, I will need to use a panhard bar which I originally wanted to avoid.

What I would like to know is, how good is this rear for some equal road coarse and 1/4 mile runs. I am wanting some adjustablility for both venues and prefer minimal packaging problems. I will be running a back seat. I already have the stock 12 bolt housing but haven't bought any parts yet. If there is a more suitable solution out there, I don't have a problem changing directions. Fabrication is not a problem. If you have visited my site, you can see how far off the deep end I have gone so far. Let me know what you suspension guys think. Thanks in advance.

Mike

[Q ship]

I don't have the experience or knowledge of theory that a lot of the guys here have, but i do know from reading and my own experiments with the rear suspension on my Caprice(same basic design) that the factory 4 link is far from optimal. It depends on soft rubber bushings and control arm flex to articulate-change any of it(harder bushings for example) and it will bind up, leading to a loss of travel and poor handling. When I get serious I will be looking into a three link setup with a panhard bar.
Here's just a taste of whats possible. And yes it's a Mustang rear suspension, but you can see the similarities to the GM 4 link.

[dennis68]

Mike, Mike, Mike--you really don't want to actually install the system so many are trying to get rid of. The factory converging links biggest problem is the bind issue from the UCA attempting to rotate and flex at the same time as a characteristic of the design. So, you replace the rubber/poly bushings with rod ends and stand back to admire your work. All is good until you plug the numbers into the analyzer and find that the RRCH is like 3 feet or something (I don’t have my notes). You already pointed out the huge pinion change through bump with the 9” arms.
The Mustang guys with the fox chassis have already tried every conceivable variation of the converging 4-link system, the conclusion unanimously has been to scrap it.
The way to fix this or in your case to avoid having any of these issues is either building a custom 3or4-link, Satchell link (which I would think would get used more often) or truck arms. If you were willing to go through the trouble of fabbing mounts for the converging link frame mounts then building 3or4-link mounts would be just as easy.
I believe Norm is still running this system somewhat successfully in his G body, he is the exception I suppose.

[TurboLark]

To eliminate the bind, use spherical ends on the arms and the upper rear bearing found on this page.. HERE
If you are looking for ultimate road cousre handling, it aint the best, but it can be made to work very well for the drag strip and street. Combine the Wolfe Racecraft stuff with the correct coilovers and you should be in a good position.

[MuscleRodz]

I have not fabbed any mounts yet, so this is why I asked now. I still would like try a Satchell link but custom built for the car. Satchell has not been talked about much I will start this thread over asking the pros and cons of Satchell link. I think 3 link and 4 links have been very well discussed and do not need repeated.

Mike

[93Polo]

Are there any three link kits out for the Chevelle? I like the Mustang conversion above.

Some of the Mustang guys were pulling out one of the upper arms and running a panhard rod to center the rear. too.

[MuscleRodz]

I think I remember someone on this site mentioned a three link conversion was in development but have not heard of anything since.

Mike

[dennis68]

Someone (shhh) here is working on a bolt on 3-link for 1st gen Camaros. Could be adapted to A bodies I suppose, but it would probably be as much work as building your own.

[Marcus SC&C]

I have to agree with the general concensus,forget the Chevelle 4 link if you`re building from scratch. The RC is too high and the non linear binding issue can only be partially resolved with bearings or heims. It`s a geometry issue,not a bushing bind issue. Personally I`d go wit ha nice 3 link with panhard bar or watts linkage. If you want to avoid radical pinion angle changes you`ll need to either invade the backseat area or compromise a little and mount the link offset behind the centerline rear. We chose the latter on out current 3 link/PHB project because we plan to offer it as a package and most folks won`t chop up their back seat. The pinion angle change is still more than ideal but it`s quite a bit less than stock and overall it`s a HUGE improvement over even tweaked factory style converging 4 link. As a bonus you should be able to use the stock Chevelle LCA mounts. Marcus SC&C

[MuscleRodz]

Marcus,
invading the back seat area would not be a big deal if it could be hidden under a center console. I am not running a stock back seat. Probably be nothing more than 4th gen rea seat. If I went rearward some and invaded the rear seat over the tunnel, do you think I could get enough upper arm lenth for decent handing. I know I will need to add a panhard bar. Stock 3rd or 4th gen control arms are about the correct length for the lowers. What length upper would be required for good handling characteristics?

Mike

[dennis68]

Mike, the upper link should be at least 50% of the length of the lower links. Even a half ass 3-link will provide better handling than an OE style converging link. I looked real heavily at the Satchell link for awhile (still think about at times). Very good system, simple to construct with no packaging limitations. Just something to think about.

[93Polo]

Good info

[Marcus SC&C]

Mike,removing the rear seat issue you can certainly put together a very acceptable 3 link. Handling really isn`t the issue with the shorter upper links it`s the rapid pinion angle change. That said when you stiffen up the rear spring/shock rates and lower the car you minimize the amount of travel typically used so you can actually end up with less pinion angle change than the original C4L (converging 4 link) suspension. Dennis is absolutely right. Even with our adj. 3link/PHB set in the "you`d never really set it up like this but let`s see what happens if we do anyway" holes it still easily out performs the original C4L in both handling and feel. Marcus

[Norm Peterson]

Some of the Mustang guys were pulling out one of the upper arms and running a panhard rod to center the rear. too.

The so-called "poor man's 3-link" has mostly fallen out of favor since the development of a number of "real" 3-link conversions. A PM3L doesn't (can't) completely remove the lateral loads from the remaining UCA. Since it's no longer balanced by the other UCA the behavior is not symmetrical in left vs right turns, and acceleration tends to stiffen the suspension (due to the angled UCA inducing loads in the PHB).

Norm

[93Polo]

The so-called "poor man's 3-link" has mostly fallen out of favor since the development of a number of "real" 3-link conversions. A PM3L doesn't (can't) completely remove the lateral loads from the remaining UCA. Since it's no longer balanced by the other UCA the behavior is not symmetrical in left vs right turns, and acceleration tends to stiffen the suspension (due to the angled UCA inducing loads in the PHB).

Norm

Thanks, I went for a ride at a Road Atlanta track days in a fox body Mustang that was running the poor man's 3 link. A real budget racer who was running it. Running some quick lap times on a very little $$$

I'll keep an eye out. I'd like a developed kit for the A-body and pro-touring just catching on for these cars. The Chevelle isn't going on the road for a while.