Fays2 Watts Link installed

Turbo6inKY

Short Guy
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Joined
Jun 18, 2001
So, I bit the bullet and snapped up a Fays2 Watts Link and put it in my car:
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I put thirty miles on it tonight, and my first impressions (having not driven the car hard at all):

1) Slight understeer upon initial corner entry, then it just grabs and turns. The significance is that the car is on crappy all seasons right now. I took highway ramps that got scary at 55 on NT01s at nearly 70 on crappy all seasons, with zero drama. The car actually feels slower in turns. Then you look at the speedometer. The understeer might be able to be tuned out. Moving the propeller vertically in the frame is supposed to alter that behavior. Experimentation will expose the answer.
2) Body roll is almost completely gone, which is expected when the roll center gets locked down just above the differential, and I'm using stock swaybars. All you people with the massive swaybars have missed the point completely.
3) Tracks straight as an arrow over bumpy pavement and freeway expansion joints. Before installation, the back end would squirm around all over the place.

So, to try and anticipate a few questions, my commentary follows on the installation.

The hardest part is getting the big red frame installed. In my case, I needed to drop the exhaust to make enough room to get it in place. You locate it around a small brace welded to the frame rails just behind the axle, C-Clamp it, then start drilling holes. Four of them. You drill a 3/8" pilot on the outer side, then enlarge it to 1/2", then use a fixture that comes with the kit to drill the inner hold from the outside at 3/8".

The kit uses shoulder bolts to keep you from crushing the frame rails. It came with bolts with 2.5" long shoulders (1/2" diameter shoulder, 3/8" threaded portion). The 2.5" was too long. I had to stack six or seven washers to snug it up. No big deal, except for the tire clearance. After contacting Jim Fays himself, relating the issue, and also asking about some torque values, he started revising his manuals and sent me new bolts with 2.25" shoulders. Problem solved.

Installing the axle clamps came next. If your car is undercoated like mine was, you need to remove that undercoating on the axle tubes (and the frame rails), or the suckers will spin around under load. I also had to grind off the driver side inboard brake line bracket. Dropping the swaybar will give you more room to deal with the axle clamps, as well. If you have one of those fancy super-stiff chassis mount sways, take it off and sell it on Ebay. You don't need it anymore with this thing.

Once you have the axle tubes on, you install the propeller and the link bars. Follow the directions, make sure the bars are EXACTLY the same length and arranged at the proper angles, and torque it all down with some threadlocker. Seriously, the hardest part of the install was the drilling. Have a new, sharp drill bit and use cutting oil. The rest is a bolt-on.

You will need a 1 & 1/8" short socket and wrench. Go buy them. Now.

I'll be campaigning the car in CAM in the local SCCA region this year. I'll update this thread with my experiences. Please feel free to pester me with questions. If I can't answer it, I'll try to test it and answer it. My first event is March 15.

Other important information: I have the old ATR 2.5" dual exhaust system with the Pit Bull mufflers ahead of the axle and side exit tailpipe that go over the axle. As I mentioned earlier, I had to disconnect the exhaust from the test pipe (or catalytic convertor, if you still have one), and pull the tailpipes out of the hangers and let it rest on the rear axle to make enough room to get the Watts frame installed. Your mileage may vary. Exhaust clearance is the great unknown with this kit. Budget time to work around exhaust clearance problems into your install.
 

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Could you share the negatives? I haven't found any yet, and it would be nice to see what the complaints are.
 
Exhaust being one of the Big negatives on our cars, Added weight?, Loss of Articulation?....

"These are just my thoughts" There are only a few others here with those and yes there is controversy over if they are actually needed or not to improve the handling with the stock 4-link and the aftermarket suspension products out there right now... The 4-link suspension design on cars was designed to keep the rear end centred and it does a good job keeping it from moving side to side...

For what it's worth, We ran our car hard for 5 years at protouring autocross events and tested over 3 different suspensions, qualified several times for the top shootouts. I always gave people ride alongs in the car to let the suspensions speak for themselves... All we had was all DSE aftermarket suspension products on our old white T-Type test car, ran 295-35/18's in the rear Without a frame notch and Not one rub mark on the frame due to the rear end moving side to side. The rear tires always stayed planted to the pavement while other g-body's with other suspension setups had rear tires lifting off the ground around hard turns! Doug Lutes being one of them.... Mine articulated better thus giving me better traction throughout the turns...

WE currently have a customer running E Street Prepared in the SCCA classing in the Texas region who recently took 2nd place only a few points below a Mustang who ran full slicks most of the season, not too bad! We wish you luck in the SCCA and if there is anything we can help you with don't hesitate to ask...
 
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I had contemplated running this, that was before all the frame work and paint and all. Curious to see how you make out.
 
The car actually feels slower in turns. Then you look at the speedometer.

That's one of the biggest things you notice. The car is much easier to drive hard. Much more predictable and controlled. You're going to love it !!
 
I contemplated that setup for a while, it looks really nice. I'd love to hear how it works out for you guys once you get some sticky tires on there. One of the things that worried me from a geometry perspective was the conflicting roll centers between the factory 4 link suspension and that of the Watts link. I do not have any experience with the watts link in a g body but from what I've gathered it seems that having compliant bushings in the control arms kinda eliminates the conflicting roll center issue, is this how your car is setup? Its hard to tell from the picture but are you running stock control arms with Johnny Joints pressed into the axle housing?

Paul
 
They are stock control arms with factory rubber on the chassis side, and poly on the housing side. It's been my observation that when the rear articulates, the chassis end of the UCA experiences a lot more off-axis movement than the housing side. I have a set of factory bushings to go into the housing, but couldn't get the damn poly to budge while I had it on the lift the last time. Instead of making a mess, I left it in for the time being. I plan on replacing the housing side with rubber prior to my first event, I just need to remember to call HRPartsnstuff and get their bushing tool. It's bit pricey at $90, but I guess that's cheaper than breaking the ears off my housing trying to remove them with the BFH.

The Watts' roll center will dominate over the stock one. It's steel and heim joints competing against rubber and urethane. One might even consider removing one of the UCAs. They only handle pinion with the Watts installed, though I'd want an opinion from an actual chassis engineer before trying it myself.

I have about 200 miles on the Watts on the street. So far, so good. I found a bind with the axle at full droop (as in I'd likely only see it in operation if the car left the ground) that I'm going to attempt to adjust out tomorrow. It looks like I can get it done with a small adjustment to the passenger side axle clamp and slightly lengthening the link bars.
 
I have the bushing tool around somewhere. If I can find it this weekend, you're welcome to borrow it.
 
No worries, I got them swapped using a ball joint press and some ingenuity.

Good thing, too. The passenger side UCA had popped off the chassis side bushing. No damage, I was able to press it back in and reinstall the arm. Lucky.

So, I'll update my previous stance. Running any poly with this Watts is a bad idea. Just don't.
 
Turbo6inKY,
Are you saying that the chassis side bushing popped off due to binding of the control arm caused by the stiffer poly housing bushings? If so that seems like a good amount of bind uh? Do you think that with the conflicting roll centers the wheel rate could change in a manner that would result in inconstant handling characteristics? Thanks in advance for your insight on this setup.

Paul

P.S. When is your first event? I'm looking forward to seeing the results.
 
Turbo6inKY,
Are you saying that the chassis side bushing popped off due to binding of the control arm caused by the stiffer poly housing bushings? If so that seems like a good amount of bind uh? Do you think that with the conflicting roll centers the wheel rate could change in a manner that would result in inconstant handling characteristics? Thanks in advance for your insight on this setup.

Paul

P.S. When is your first event? I'm looking forward to seeing the results.

Well, if the housing side can't move laterally, then all the movement ends up at the chassis side, so yes. Too much.

As for the conflicting roll centers causing inconsistent handling, in a thought experiment you have a valid point. I've not seen it in the real world yet. There's little room for a conflict. The Watts clearly dominates, or I would have bound up and spun instead of popping the bushing.

But we will see. An autocross is going to be the definitive test. My first KY Region event is March 15 at The National Corvette Museum's autocross pad. There is a chance I could make a TrackX event later this month, though.
 
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