Watts Link Setup

[Dreadknought]

I've been running my Fays2 Watts for about 4 months now and I cn't complain. I unfortunately haven't had the tires to be able to tell how much I am getting out of it and my other upgrades. That being said while I am under the car today, I want to make sure that I've got it at the correct setting.

I have my car running pretty low on a set of ST coilovers and when I followed the instructions from Fays, I set the link bars at parallel. With the bars set as such the center bolt fits into the second bolt slot from the top of the mount.

What I am wondering is if I can count this as the "neutral" setting for my particular vehicle. I understand how to tune it to my needs and tastes after that, just not sure if the middle setting is neutral setting or if it varies by car for ride height.

Thanks for any help. I have called Jim Fays but got no answer, and searched before hand but no cigar. Would like to have this done tonight before I go to a shooting competition tomorrow.

 

[Philostang]

I'm not exactly sure what you mean by "the neutral setting." So this may come down to figuring out what you really think you need to know.

I seem to recall reading somewhere that the middle hole in the Fays Watt's was supposed to replicate the rear roll center of a stock S197 Mustang (obviously, this is a static comparison at ride height).

Once you lower the vehicle, that goes out the window, so reproducing the same relative rear roll center requires dropping the prop center bolt. How much, one or two settings? Who knows w/o careful measuring, etc. But I'm not really sure why it matters, except as an academic point.

On mine (modestly lowered) I just set it at one spot below the middle setting, then drove. It sucked for me (not on the street, just when driven hard at the track). So I went down another...then drove, then another drop (more driving), etc.

The point of having the adjustability in the first place is to be able to zero in on what performs optimally for your set up. If there was a definite "pre-set" answer, they'd just build it that way and forgo the extra expense/difficulty of making the unit adjustable.

So again, I'm not really sure what your asking, or better, why you would want to know something like that. You're lowered, so there's likely no serious harm in starting one notch below center (or the center for that matter). The car will be plenty driveable on the street, and when you have time you can do your test and tune.

(edit: re-read OP's post) Short answer: yes "it" varies by ride height (also assuming an even drop, so if you dropped the rear more than the front as many spring sets do, it varied with that as well), if by "it" you mean replicating something like the OEM front-to-rear roll center relations (and if by "neutral" you meant something like what Ford thought to build into the car).

Best,
-j

 

[Sleeper_08]

Philostang

For me this is a very timely post as I was thinking about dropping mine this season.

When you changed the center bolt position did you also readjust the rest of the linkage to get the links parallel to the axle again?

 

[Philostang]

Hey Sleep,

No, I didn't reset the linkage, because there's no need to do it if they were originally set up parallel. So it's just the one bolt for the prop and you're done.

Of course, some folks like the cleaner look of parallel links, so you could do that. I was at the track and didn't want to take up the time for it (and I don't think its visible enough to care about it's looks).

Oh, speaking of doing this at the track, here's an obvious *duh* recommendation. I had a hell of a time getting socket-access to the center bolt once it was dropped to the lower positions. So a 10 minute job turned into 2.5 hrs of walking through the paddock trying to find someone with a short enough socket or wrench. I thought I had the tools I needed, because in the back of my mind I knew I had "something" in the track box that would fit...turns out it didn't once things were moved. So be sure you have all the tools you might need if you're going to dial it in at the track.

Best,
-j

 

[Sleeper_08]

Hey Sleep,

No, I didn't reset the linkage, because there's no need to do it if they were originally set up parallel. So it's just the one bolt for the prop and you're done.

Of course, some folks like the cleaner look of parallel links, so you could do that. I was at the track and didn't want to take up the time for it (and I don't think its visible enough to care about it's looks).

Oh, speaking of doing this at the track, here's an obvious *duh* recommendation. I had a hell of a time getting socket-access to the center bolt once it was dropped to the lower positions. So a 10 minute job turned into 2.5 hrs of walking through the paddock trying to find someone with a short enough socket or wrench. I thought I had the tools I needed, because in the back of my mind I knew I had "something" in the track box that would fit...turns out it didn't once things were moved. So be sure you have all the tools you might need if you're going to dial it in at the track.

Best,
-j

Glad I didn't try to do it at the track!

I'm getting way too old for crawling under cars at the track so was planning to get it reset when checking out in preparation for the season.

Presently it is set in the center. Any suggestions on how many holes to drop it with a car on Steeda Competition springs which per Steeda lower the car 1" front and 1 1/4". My car is probably slightly lower in the front due to the weight of the SC, intercooler and plumbing.

In general I'm pretty happy with the handling except for two much understeer on low speed, i.e. 2nd gear, corners.

 

[Sky Render]

What kind of racing do you do? Autocross? Road course?

Set the Watts link in a new configuration (change one position at a time), then drive the car and see what a difference it makes. Ideally, go to a test and tune event so you can change the settings between runs. Like others have said, this depends on your setup and how you want your car to "feel" as it approaches the limit.

If you don't actually race the car, it doesn't matter.

 

[JAJ]

A couple of comments on the setup issue. As others have said, it's a personal thing, so you have to mess with it a bit.

First, as far as leveling the arms, it doesn't matter if they're level. What matters is that at full compression the driver's side link doesn't hit the exhaust pipe. Last year I pulled my "stock" Fays2 frame out and replaced it with a "Shelby" Fays2 frame. It's not as tall and the stock swaybar doesn't hit it at full droop. Because it's not as tall, it only has three holes to choose from, not five.

When I installed it, I decided to change the springs and redo the arm setup as well, so I started by pulling the rear shocks and springs and installing the new frame. Then I wound the axle up to full contact on the bump stops and set the driver's side bracket with about 1/4" of space between the spherical joint and the exhaust pipe. Then I lowered the axle to normal ride height and adjusted the right side bracket to give equal but opposite arm angles. The I disconnected the arms again, dropped the axle and installed the new springs and buttoned everything up. It took a couple of hours and was a bit tedious, but when I was done it was perfect.

Because the Shelby frame has fewer holes, you end up with the propeller pivot higher than with the regular frame. I like it better up there, actually. I had lowered it one point below the middle on the original frame once, and it made the car kind of wallow around corners. I really didn't like it.

 

[Dreadknought]

Thanks for everyone's responses. Philostang, went ahead and followed your recommendation and just said fuck it, and moved the bolt to a lower position. I'm feeling out the car to see what effects it gives me.

As far as the "neutral" setting I was looking for the factory roll center. But I think this may be a moot point from what I have been reading. Thanks ll for the help.