I know there's a post about the Fays2 Watts link here (http://www.chevelles.com/forums/showthread.php?t=275738&highlight=watts+link). It's a very nice piece but it requires me to change my gas tank. I've already got the Spectre FI tank so I really don't want to go tank hunting again.

I'm almost finished rebuilding the front end and in a few weeks I hope to complete dropping in the LS1. I'll be moving to the rear end pretty soon.

I'll probably end up with the UMI adj UCAs and the tubular LCAs for the rear. I wanted to also run a panhard bar but i'd rather run a Watts link.

I saw this for sale speedwaymotors.com. http://www.speedwaymotors.com/Watts-Link,3398.html

It's a different mounting setup, totally opposite from the Fays2 setup but seems like the concept is still the same. It looks pretty narrow and I believe it's really more for T-bucket or Model A applications (doesn't look heavy duty).

Can anyone speculate how this will fit in an 66 A-body and also, if you think it's strong enough for a street driver chevelle?

It's an awfully good price and you can request longer rods...

http://www.speedwaymotors.com/RS/SR/Product/91649023_L.jpg

the Speedway link won't open for me..
but if it's one that mounts the center pivot to the housing, i'd think it might add some unsprung weight to the housing- and put a LOT of load on the housing, too.
of course, all the extra mass is added in the center, unlike the setups that mount the center pivot to the frame, which adds unsprung weight and puts all the sideways loads out at the end of the axles where it probably matters more.
in the end, it's probably close to an even trade off between the two, i guess, but i'm definitely not an engineer.

It looks like their site is down. Even my picture above (linked to their site) is not showing up.

Yes, mounting to the differential cover is a concern for me also. I actually didn't think of the impact to unsprung weight either. It might just be tradeoff given a better suspension setup.

A lot of times though, I feel many of the things we do here as "hot rodders" over build parts, afterall better safe than sorry, right?, but I will not be tracking this car so I was hoping for some real live experience from some folks as well --> might be a long shot :yes:.

These things are not impossible to fab up yourself by any means... but you are required to do a bit of "engineering" which is short for making design tradeoffs to meet the requirements.

Tradeoffs with the Speedway "kit" that I see:

1. It locates the RC well above the rear axle. Even higher than a stock setup. This causes more weight transfer to occur through the axle tilting weight jacking affect. And since you have that weight transfer there you cannot have it through roll stiffness. So all of your anti-roll stiffness gets put in the front. That is a lot to ask for one end of the suspension and not a very balanced formula.

2. It requires a lot of vertical clearance above the axle. You may have room on a Chevelle, maybe not. Definitely NOT enough room on an El Camino though and I doubt very much if it would fit in a Chevell either. Especially if you lower it.

3. It uses heim joints which are not really suitable for general street use. First they transmit every suspension shock directly into the chassis making for a lot of noise transfer. Second they wear and the tolerances open up a bit and then they rattle/buzz transmitting even more noise.

4. It uses single shear mountings which are not as strong as double shear. Might be OK on a 1500 lb roadster but probably not on a 3000+ lb A-body.

The suspension loadings are not that different from OEM actually. All of the lateral axle location loads run through the top of the center housing on the C4L stock setup.

While a Watts linkage is probably the best lateral location device for a solid axle, the incremental gain in performance is probably not worth the complexity cost. IMHO a long length PHB is very tough to beat for simplicity, packaging, and effective location of the axle.

While I understand the critical spacing between tank and axle, do not forget to also consider the exhaust requirements in that area as well ;)

These things are not impossible to fab up yourself by any means... but you are required to do a bit of "engineering" which is short for making design tradeoffs to meet the requirements.

Tradeoffs with the Speedway "kit" that I see:

1. It locates the RC well above the rear axle. Even higher than a stock setup. This causes more weight transfer to occur through the axle tilting weight jacking affect. And since you have that weight transfer there you cannot have it through roll stiffness. So all of your anti-roll stiffness gets put in the front. That is a lot to ask for one end of the suspension and not a very balanced formula.

2. It requires a lot of vertical clearance above the axle. You may have room on a Chevelle, maybe not. Definitely NOT enough room on an El Camino though and I doubt very much if it would fit in a Chevell either. Especially if you lower it.

3. It uses heim joints which are not really suitable for general street use. First they transmit every suspension shock directly into the chassis making for a lot of noise transfer. Second they wear and the tolerances open up a bit and then they rattle/buzz transmitting even more noise.

4. It uses single shear mountings which are not as strong as double shear. Might be OK on a 1500 lb roadster but probably not on a 3000+ lb A-body.

The suspension loadings are not that different from OEM actually. All of the lateral axle location loads run through the top of the center housing on the C4L stock setup.

While a Watts linkage is probably the best lateral location device for a solid axle, the incremental gain in performance is probably not worth the complexity cost. IMHO a long length PHB is very tough to beat for simplicity, packaging, and effective location of the axle.

While I understand the critical spacing between tank and axle, do not forget to also consider the exhaust requirements in that area as well ;)

I agree with a long PHB. Dennis68 now sinned did an install on his Elky. The pics are down but the topic may still help.

http://www.chevelles.com/forums/showthread.php?t=93292

the fays doesnt move the watts further back than needed, meaing you may not fit that one either. i fabbed up my own mocking the lateral dynamics 3 link watts. heres a pic below. im running coilover, a true 4 link, and its fully adjustable with johnny joints at all 8 pts. it will require a custom tank, shortened trunk floor and a new floor piece thats raised over the rear end.

http://www.fquick.com/images/vehicles/full/23712266371.jpg?1245809599
http://www.fquick.com/images/vehicles/full/23712235018.jpg?1234929054

That one looks rather backwards to me... I would think that you want the rocker as close to the axle as possible. That would suggest the mounting framework should be on the back side instead of in front. With it in front as shown the rocker has to be at least the depth of the mounting frame further back. Which means the linkages have to be angled or the axle mounts that much longer.

There is also a LOT more mount framework on that than could possibly be required. There is no reason that the mount needs to extend further than the rocker pivot. It is also very likely that with some creative use of shear panels and double sheer mounting that the mounting could be made very low profile.

Actually as I look at again and think about it... you could take advantage of the round pumpkin shape to locate the supporting frame outside the hump and get that much further forward. Really should be able to fit one of these things without whacking the fuel tank. Exhaust would be close to impossible but not the fuel tank.

maybe it appears backwards, but thats how many people run them (although your points are valid). the crossmember location was chosen for exhaust clearance, tank clearance, and the ability to use it as a upper coilover mount as well. in addition, the famework does actually straddle the pumpkin and there is a limited space btwn them moving the watts as far forward as possible. in order to remove the cover, the ucas have to be removed to drop the rear all the way down. other than changing the fluid every "x" amount of miles, i dont see why its a big deal.

i really dont see ANY way of fitting one with a tank and full exhaust. i spent hours dreaming up this setup so that i could run full exhaust, but the tank is a must to cut. in order to get a full exhaust out the back, you must either run the pipes over the axle and before the watts by moving the watts back, or you must run the pipes over both. doing the first led to issues with the pipe being too low under the lower watts link, and doing the later had issues of getting the pipe to turn down, out, and back around the tank. at the VERY LEAST, the corners of the tank have to be cut off like with a ricks.

as far as being over engineered, you have another valid pt. if you have the background and knowledge you could do it a little lighter. but from gathering info from various other manufactures, mine really isnt that overbuilt. in addition, as stated earlier, the cross serves as the watts cross and the upper shock mount, so i didnt worry too much about its large size.

Tim

I am certainly not trying to be critical...

Actually I got kinda intrigued and took a gander underneath the El Camino. The Elkys must have a lot more space under there than a Chevelle. It looks like almost a foot between the diff and the tank.

The exhaust is the real bugger though... I have 3" pipes running through there which are darn tight to the axle and in the way of just about anything extra. Must have been bent for a Chevelle ;)

i know youre not being critical, opinions are hard to express when youre typing.

i dont have the pic anymore, but there was about 3-4" btwn the tank and the diff. i think youre right about the elcos having more room.

Tim