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Watts Link

Do you recommend a watts link setup?


  • Total voters
    20
  • Poll closed .

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323
318
Exp. Type
Autocross
Exp. Level
20+ Years
So Cal
Complete side note. Way back when in my Fox I had Poly bushings in the upper control arms and Paul Brown's (RIP, he sold me these and his subframe connectors when he was racing World Challenge at the 1994 Des Moines Grand Prix when I was a kid mounting GY tires at the racetrack. The GS-CS was the tire of choice, just to date myself.) lower control arms with poly on the chassis side and sphericals at the axle pickup lowered about an inch or two lower than stock. The lower arms gave a ton of anti-squat, roll-steer and brake hop while the upper ones were always in some type of bind. Jesus, that car handled like shiznit. It was loose as a goose in every phase of every corner. Of course, I stuck the biggest rear bar on it I could find, because that's what you do when you're 20, just to make it worse.

Long story short, don't do that. It sucks. The up side is it that this experience gave me enduring appreciation for understeer and the need to have confidence in the rear of the car to attack a corner.
 
323
318
Exp. Type
Autocross
Exp. Level
20+ Years
So Cal
I dont really think you want it that low. From what ive seen , most cars are 9-11" or so..

Chassis mounted pivots can also be a thing, it doesnt have to be on the axle...

There are so many different ways to skin the cat... The old Trans-Am I mentioned had "Mountain Dew" on the side and seemed to run fairly well. It's all the spices in the soup.

The chassis vs. axle mount is a fair debate. With the axle mount, when the car hits bumps in a corner and the chassis changes ride height, your roll couple will move around, which means the vertical motion in the car will induce a roll motion as well. With the chassis mount, if you're in the same scenario, the roll couple will remain stable (as the RC to CG height stays consistent), but the roll-center jacking forces due to the lateral load will oscillate with the vertical variations of the chassis. With a Watts, you kind of have to pick your poison. I think most race cars end up with the pivot on the axle, because the tire contact patch load variations are lower with this arrangement and whatever motion that occurs, the force is 'cushioned' to some extent by the spring/dampers. When the loads are all going through the arms, the reaction times are significantly reduced.

In this respect, the Panhard has the advantage of moving the RC vertically at a rate of about 1/2 that of the chassis. The jacking forces will change a bit with the RC-to-CG shift and the car will have a little roll/bounce cross-talk, but it may feel a little more consistent for some drivers. Others might feel the side-to-side shift inherent with the Panhard that is unsettling. In the end, I think it often comes down more to execution than the actual approach.
 

Fabman

Dances with Racecars
6,519
8,156
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
I dont really think you want it that low. From what ive seen , most cars are 9-11" or so..

Chassis mounted pivots can also be a thing, it doesnt have to be on the axle...
I've been everywhere and bounced around quite a bit between the bottom two holes (8" & 9") and also with/without sway bar and for me the no sway bar/bottom hole is decidedly faster, though I continue to test looking for something better.
I don't have a lot of power for the weight of this car, and I've had crappy brakes so I have to get off of it way early.
Being able to get on the gas sooner and harder than the next guy is a distinct advantage for me.
As I've often said: "My car will always be faster on the gas than yours will be on the brakes".
When I was running stock cars I always had a much lower roll center than the other cars. I also won a lot more races, so I guess its kind of a theme with me.
The new Kenny Brown setup is like 1 1/8" rear roll center and people seem to be loving that so to each his own I guess.
 
323
318
Exp. Type
Autocross
Exp. Level
20+ Years
So Cal
Do any of you live rear guys play around much with roll steer? I've got a friend that builds late model chassis' who does a ton of work with it. They will shift the axle around what looks like a crazy amount, but it works.
 
Do any of you live rear guys play around much with roll steer? I've got a friend that builds late model chassis' who does a ton of work with it. They will shift the axle around what looks like a crazy amount, but it works.
I haven't but I will if I ever get a car that actually gets on track... Those dirt track guys have some crazy travel on their rear ends so they really can steer that axle around a lot. Sure looks funky but I am sure it helps
 

Fabman

Dances with Racecars
6,519
8,156
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W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Do any of you live rear guys play around much with roll steer? I've got a friend that builds late model chassis' who does a ton of work with it. They will shift the axle around what looks like a crazy amount, but it works.
Yes, roll oversteer/understeer is another season to taste kind of thing.
On lower powered cars I used more roll oversteer and more powerful cars roll understeer.
On the really big power cars I used a spring rod on the right lower trailing arm to give you roll understeer on power and snap back to straight up when the gas is off. Something you can do when you are only turning left.
On the Mustang I start with a little roll over steer to get into the corners and as the body squats on power a little roll understeer to keep the car tight so my trailing arm angles are very mild. Around 3*.
 

Fabman

Dances with Racecars
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Pleasanton: 1/2 way between Sonoma and Laguna Seca
I haven't but I will if I ever get a car that actually gets on track... Those dirt track guys have some crazy travel on their rear ends so they really can steer that axle around a lot. Sure looks funky but I am sure it helps
Yes dirt cars do some whacky stuff....but they get the job done.
That's a group of guys who aren't stuck to any particular dogma. Its refreshing.
 
323
318
Exp. Type
Autocross
Exp. Level
20+ Years
So Cal
Yes dirt cars do some whacky stuff....but they get the job done.
That's a group of guys who aren't stuck to any particular dogma. Its refreshing.
The stuff that dude I know comes up with is awesome. No spec racing there!
 

Fabman

Dances with Racecars
6,519
8,156
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W2W Racing
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20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
125
112
Exp. Type
HPDE
Exp. Level
Under 3 Years
Ann Arbor, MI
....that is not the question. The question is: "Do I want to change my RC height and how easy do I want it to be adjustable". But then you say: "My buddy put a watts link on his car and he loves it". That is almost certainly because when the linkage was installed the roll center was changed at the same time. Almost always lower. Lower roll centers make the car hook up while higher roll centers help the car rotate. Chassis setup is a soup that we season to taste and if you are like me, I never stop adding a little of this or that to sweeten the pot until I find the perfect recipe so gimme all the variables in the kitchen and I'll decide what belongs and what doesn't. But not everybody wants that. How about an easy button for enthusiasts that don't have the skill or will to fool with chassis setup? Find yourself a reputable after market provider and buy what they sell, do what they say and you will have a car with parts that are engineered to work together. If you cherry pick parts based on price or folklore you have embarked upon your own research and development program. I hope you are ready for that. It can be very rewarding and educational....and it can also be a total nightmare. Choose wisely.
In my car there's no doubt whatsoever that a Watts link makes a substantial difference in cornering characteristics.

I was getting so much oversteer on my skinny wheels (275 width), but dropping the Watts just one hole down to the bottom made a world of difference right then and there. So much more fun on track - Fabman is right on in my actual experience.

Basically, we can guess all day long if we'd want one, but if you like adjusting your suspension to get different "feels" and be able to easily experiment with what works best for you for that day or that track, then the Watts link is a no brainer. Massive difference in minutes, lots of fun for me personally.

For whatever it's worth, this is coming from an intermediate, club/time trial guy who does not have decades of experience like some on this site...I know there's all kinds of ways to skin a cat, and the Watts can complicate things, but my experience is that it is a great piece of engineering that can be adjusted in minutes for different tracks, conditions, and drivers as a means to maximize performance and fun. That being said, you and your car's setup may not need a Watts, I'm just glad there's one on mine 😎
 

Bill Pemberton

0ld Ford Automotive Racing Terror
8,425
8,356
Exp. Type
Time Attack
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20+ Years
Blair, Nebraska
How can you not appreciate ye Olde unadorned solid axle Mustang! In the words of Alfred E. Neuman, " What me worry, I don't need anything, so watts the problem?" BS1 convinced me I never needed a Watts Link on my Boss S, and viewing the Phoenix Airlines Mustang , pretty hard not to see how much abuse it can take. Since in a previous life my nickname was the " Bermeister " I loved how one could launch a Boss ( or other Mustangs ) and I think I would spend the money getting a cambered rear and skip the " Missing Link ." True to Blacksheep's thoughts, many will keep said link..........missing!
 
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323
318
Exp. Type
Autocross
Exp. Level
20+ Years
So Cal
A Watts vs. a Panhard bar is an old debate. The Watts has advantages, I don't think there's much lap time there. The question is whether the added complexity of the Watts actually turns into speed. A well set up Panhard is 99% as good as a well set up Watts, but it's easier, lighter and often stiffer. Further, a well set up Panhard will kick the shiznit out of a poorly set up Watts. You've got to be slicing the onion pretty damned thin before the difference between the two matters, as long as you can hit the same roll center heights.
 
125
112
Exp. Type
HPDE
Exp. Level
Under 3 Years
Ann Arbor, MI
A Watts vs. a Panhard bar is an old debate. The Watts has advantages, I don't think there's much lap time there. The question is whether the added complexity of the Watts actually turns into speed. A well set up Panhard is 99% as good as a well set up Watts, but it's easier, lighter and often stiffer. Further, a well set up Panhard will kick the shiznit out of a poorly set up Watts. You've got to be slicing the onion pretty damned thin before the difference between the two matters, as long as you can hit the same roll center heights.
Dare I say, for many of us on this site having all 4 wheels planted on the ground as much as possible to get around the track fast and reduce lap times is important. Not all of us are pros or have the time to become drivers that can safely get around corners time after time on 3 wheels! HUGE respect to those that can, but I bet most drivers viewing this site and considering a watts are weekend warriors that don't have the time or money to risk driving like the dudes that blow our minds in BS1's pics. That's so cool and super admirable, but I don't have sponsors or a team to support me and my hobbies. Darn. And I can say with little doubt, driving a car at speed and to the limits safely is more difficult than landing an airplane!

So, for most of us, I would guess that if a watts and phb are about 99% even in terms of lap times, and the watts is potentially safer for most drivers with easy adjustability, then a watts could be a great way for many to "grow" into the sport, while feeling planted around corners and being able to more easily find the limits of the car. In my experience it's still totally "analog" and mechanical, not electronic at all, I'm not gonna break it, and personally so much more fun to drive and find the limits of the car.

NONETHELESS, whatever setup you have don't be afraid to start adjusting what you can to improve the performance of the car for you on your track with your particular tires. I probably could have done that earlier but hey, live and learn.

Blessings to you all on this beautiful day!!
 

xr7

TMO Addict?
708
823
Exp. Type
Autocross
Exp. Level
10-20 Years
Minnesota
My only opinion on the Watts linkage is this, if you are running the White Line Watts Linkage you better keep a very close eye on the bellcrank that the two links attach to that's mounted on the diff cover. There is next to nothing for welds holding the lugs onto the bellcrank and you can't really inspect the welds unless you remove it.
 

Bill Pemberton

0ld Ford Automotive Racing Terror
8,425
8,356
Exp. Type
Time Attack
Exp. Level
20+ Years
Blair, Nebraska
Good points 302Fam, and for those of us who have hammered the curbs for years , either because it was the shortest line between two points, it helped rotate the car, or simply because it was the fastest line, the lack of a Watts link was likely pretty advantageous for me in particular. I know quite a few other drivers/friends who are Berm Pilots and though we are not in the same " League " as Andrew Aquilante in BS1's pictures I will echo the strength of ye olde solid rear axle with little mods.

The interesting thing to me was how few of said friends had Watts Links, but a bunch of them had spent the money to get cambered rear ends -- done by Cortex.
 
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Fabman

Dances with Racecars
6,519
8,156
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
I would def put my $ in a cambered diff before a watts.
Definitely a good purchase.
Besides the increase in grip my tire wear has evened out quite a bit so I get more out of a set of tires than I used to.
 

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