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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
I've got to stay in my lane on this one. My live rear experience is pretty skinny. You're 100% correct about the RC movement with respect to the CG. I do remember that the fastest of the old Trans Am cars often used a Watts with the pivot on the bottom of the pumpkin & it swiveled about a vertical axis, which I thought was clever. When I asked about it (& remember, this was 25 years ago), the engineer said it was an effort to make the car as soft in roll as they could to improve traction at corner exits. As to what to actually use on an S197, @Fabman and @blacksheep-1 is who I would ask.
 

xr7

TMO Addict?
706
821
Exp. Type
Autocross
Exp. Level
10-20 Years
Minnesota
Running the Watts in my Boss.
The first time I saw a car with watts was a Funny Car back in the early 70's, Blue Max Mustang IIRC. Not that it matters here but I always thought the 71-73 Mustang was the best looking funny car back when the cars at least had some resemblance to the original car.
 
323
318
Exp. Type
Autocross
Exp. Level
20+ Years
So Cal
Running the Watts in my Boss.
The first time I saw a car with watts was a Funny Car back in the early 70's, Blue Max Mustang IIRC. Not that it matters here but I always thought the 71-73 Mustang was the best looking funny car back when the cars at least had some resemblance to the original car.

You're not wrong. That body style was absolutely perfect for a funny car.
 

Dave_W

Cones - not just for ice cream
986
1,277
Exp. Type
Autocross
Exp. Level
20+ Years
Connecticut
It seems like some time in the late 60's or early 70's, a bunch of funny car teams hired painters from the LA lowrider scene. And they had totally awesome designs.

If I ever build a car for CAM class autocross (not using the Boss - can't mess with the hocket sticks), I fully intend to give it a paint job like a 70's funny car. Gotta have a cool car name to paint down the sides, like Cone Crusher or Slalom Dancer or (Late) Apex Predator.

Wow, this thread has taken a turn.
 

Fabman

Dances with Racecars
6,519
8,155
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Some of the points of contention in Billys article do not apply to the Cortex Watts link.
You are not stuck with a high roll center, the range of adjustability is very wide and the arms are plenty long so angles are not severe. Its also much lighter than other variants. Other brands suffer from some or all of these characteristics and more.

Note the range of adjustability. From higher than stock to well below the stock RC and 2 places in between.


269927594_291082239653900_8911935196867714548_n.jpg

There is a street version too with bushings instead of rod ends to minimize NVH.

I will get some measurements tomorrow and report back here.
 
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Fabman

Dances with Racecars
6,519
8,155
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Okay, here are the numbers:
The car at my ride height w/25.6" tall Hoosiers with a panhard bar would have a rear roll Center of 10".
The Cortex watts has positions for 8", 9" 10" and 11".
Choices, I like choices.
 
323
318
Exp. Type
Autocross
Exp. Level
20+ Years
So Cal
Okay, here are the numbers:
The car at my ride height w/25.6" tall Hoosiers with a panhard bar would have a rear roll Center of 10".
The Cortex watts has positions for 8", 9" 10" and 11".
Choices, I like choices.
Just spit-balling, how low would it be if it were mounted horizontally under the pumpkin?
 

Fabman

Dances with Racecars
6,519
8,155
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Just spit-balling, how low would it be if it were mounted horizontally under the pumpkin?
That would depend on how you do the bracketry...the 8.8 rear has a cast center section.
The 9" has a steel center section which is much more friendly to the welding of brackets.
The 9" is also a bigger pumpkin which would push the roll center even farther down low.
I had already figured out a way to lower the current bell crank down much further but after running mine at 8" I don't think it would be an advantage for me.
Right now I can flat foot the car long before the apex and it has 100% bite. Lower would just push the car towards understeer. (Push towards understeer...HA!)
 

Fabman

Dances with Racecars
6,519
8,155
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Just spit-balling, how low would it be if it were mounted horizontally under the pumpkin?
I have had rear springs from 250# to 450# in 25# increments, I've had the watts in every hole and used 3 different rear sway bars, and no sway bar.
I've used 3 different types of drop brackets with varying degrees of anti squat and roll steer.
It has all lead me to the current setup and whenever I change it to something else, I always go back to this same setup.
The rear is hooked....what I need is better brakes. And that, is in the works. ;)
 

Fabman

Dances with Racecars
6,519
8,155
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
(Pic of the current setup)

294148394_415952353833554_6272843912765076302_n.jpg

This allows me to loosen the car up when needed by installing the quick pin in the sway bar link.
If I need to tighten it up I just remove the pin and zip tie the link out of the way.

309906806_436117288505499_1339919665133193535_n.jpg

Its a 30 second change that I can do in the hot pit during a session....and have.
I ran both with and without the sway bar at Nationals as the conditions kept changing from warm and sunny to rain and gloomy.
Choices, did I mention that I like choices?

310035379_360725362866147_8667537945053111460_n.jpg

That's @Albino500 walking over with the snips to cut the zip tie and hook up the sway bar while my son checks tire temps and pressures.
We were in and out of the hot pit with data and swaybar/tire pressure changes in like 90 seconds. (A memory pyrometer really helps here)
Makes fine tuning on the fly quick and easy.
 
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Dave_W

Cones - not just for ice cream
986
1,277
Exp. Type
Autocross
Exp. Level
20+ Years
Connecticut
This has been your Roadkill zip-tie moment for the episode. ;)

Are you looking at the sweet AP Racing / Essex Radi-Cal setup? They offer them using the same pad outline in either 18mm pad thickness (9660 caliper) or 25mm (9668 caliper). The 9668 is about a pound heavier and 14mm wider than the 9660, so it may affect clearance with some wheels.
 

Fabman

Dances with Racecars
6,519
8,155
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
This has been your Roadkill zip-tie moment for the episode. ;)

Are you looking at the sweet AP Racing / Essex Radi-Cal setup? They offer them using the same pad outline in either 18mm pad thickness (9660 caliper) or 25mm (9668 caliper). The 9668 is about a pound heavier and 14mm wider than the 9660, so it may affect clearance with some wheels.
I have a brembo club race system up front and stock calipers in back with no ABS so I’m constantly locking up one or more tires. The coyote control pack doesn’t talk to the 3 valve ABS block so I have been dealing with it by backing out of the throttle way early which is terrible for lap times. I just purchased a boss 302s ABS block and brembo 4 piston calipers that match my front calipers so this should help immensely. Stay tuned.

C8C78CF3-960C-4C1D-9CC5-57C24E01607F.jpeg
 
6,363
8,187
Some of the points of contention in Billys article do not apply to the Cortex Watts link.
You are not stuck with a high roll center, the range of adjustability is very wide and the arms are plenty long so angles are not severe. Its also much lighter than other variants. Other brands suffer from some or all of these characteristics and more.

Note the range of adjustability. From higher than stock to well below the stock RC and 2 places in between.


View attachment 80352

There is a street version too with bushings instead of rod ends to minimize NVH.

I will get some measurements tomorrow and report back here.
Well, Sal, the reason /i said your car "didn't count" is because you have an entirely redesigned suspension system, I have no argument with a car that was designed (or redesigned) to use a Watts, but in production class cars, I'll go with a Panhard bar any day of the week, The Boss 302 platform is probably the zenith for stick axle mustangs, there's not much there that needs to be changed,, therefore PHB.
 

Fabman

Dances with Racecars
6,519
8,155
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
That would depend on how you do the bracketry...the 8.8 rear has a cast center section.
The 9" has a steel center section which is much more friendly to the welding of brackets.
The 9" is also a bigger pumpkin which would push the roll center even farther down low.
I had already figured out a way to lower the current bell crank down much further but after running mine at 8" I don't think it would be an advantage for me.
Right now I can flat foot the car long before the apex and it has 100% bite. Lower would just push the car towards understeer. (Push towards understeer...HA!)
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...
 

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