Ok I know I read the thread before but I cant remember which site it was or who wrote it bit it dealt with questions regarding the length of watts link arms compared to the propeller and also about when the links should be parallel.

I recently ordered up a propeller kit and mounting plate from Jim Fays and will be moving on with fabbing things up this weekend. My questions are more or less what I mentioned above. Namely, whats the desired length of the links to the the length of the propeller and is it desired to have the arms parallel to each other at static ride height?

Regarding the second question, Steeda sells a Watts link for S197 Mustangs that utilizes a pair of slider boxes for the links. They specifically say in the instructions to reset the arms to parallel anytime the RRCH is changed. Heres a link about that http://www.steeda.com/directions/555-2525_steeda_watts_linkage.pdf

My understanding is that if the links are parallel at some point in the movement of the rear end then all is good but this info from Steeda contradicts it. Obviously they may use this as some type of "selling point" which is more or less useless other than to say that you can do it.

More or less Im just looking for some basic Watts link tech about how to best set it up not neccesarily how to build it.

steeda says that because it is the easiest. they absolutely!!! do not have to be parallel at ride height but rather equal and opposite. call fay and he will confirm this. it just makes it much easier to setup when parallel.

also remember that if your RRCH is not at the perfect center of the axle at all times (which it wont be for a chassis mounted watts), you will get side to side movement while in roll and compression or rebound. think about a "T" with the bottom being the pivot pt, or RRCH, and the top being the axle. now imagine the body staying flat, and the axle rolling. as it rolls, the top moves to one side based on the pivot pt, but the body did not move. youve just ended up with axle migration.

your questions about length are valid, and im not sure i have a good answer. hopefully someone else will. but i did use the 6" center and 16" arms. i cocked the propeller slightly which made the distance ~5.85". this meant that the vertical difference btwn the two axle mounts HAD to be the same. this makes setting the mounts up a little easier, because as long as you are close to, but not over 6" it can be corrected.

Tim

I don`t see any reason to make life any more complicated than it already is. There`s always someone trying to prove without a doubt mathmatically that a bumblebee can`t fly. Make the links as long as your packaging will allow. Set the car up at ride height, make the links exactly the same length and level them with the ground and the chassis. Done. No trig to screw up, it`s so simple a cave man could do it. :p Lateral axle migration is practice is about 1/8". It doesn`t get any better than that and if it did you couldn`t feel it anyway. Occams razor is your friend. :yes: Mark SC&C

Ok that pretty much reaffirmed what I already thought to be correct. I just got thrown for a loop seeing a company expressly advising to reset the angle of the arms anytime RRCH is changed. I may do some slider boxes anyways although not as bulky as steedas as I dont want any bolt on brackets and Im not an opponent of added adjustabilty. Ill be making my own but there are PHB slider boxes that give me som good ideas for what I can do and in this case Im not too worried about double shear mounting.

I will take the advise of making the arms as long as possible. I figure as with most things longer is better and less angular change through suspension travel. My proposed sway bar mounting ideas may limit the Watts as Id like the sway bar getting the real estate on the ends of the axles but Ill make sure the watts is right next to them.

as mark stated, it can be easily over complicated. i actually set mine up level, but i had the suspension compressed to get them there. once welded in, the car went back to normal ride height and they were no longer parllel and no math was involved.

im really not trying to prove anything, just letting those that dont have adjustment know that its not the end of the world. if i had it to do it over again, i would have used the mounts like mark sells. not only is it easier to setup, but welds are friggin permanent.


Tim