cortex watts link

[Gray Ghost GT]

Do you guys know if there's a lot of work involved with adjusting roll center on any of the watts links available? Once the control arms are initially setup, can you move the props up or down as you wish without messing with anything else?

On my Fays2, I "set it and forget it". I don't change the roll center for daily driving vs. road course activities.

I recommend setting the roll center-propeller one hole below neutral.

 

[neema]

On my Fays2, I "set it and forget it". I don't change the roll center for daily driving vs. road course activities.

I recommend setting the roll center-propeller one hole below neutral.

I'm more concerned with the ability to test different roll center heights while at the track or autoX. I feel like it would be time prohibitive if you had to align the control arms. Just curious

 

[Norm Peterson]

If you mean the two lateral links of the Watts link, you don't have to touch their inclinations once you've set them the first time. There is nothing 'sacred' about them being horizontal with the car at rest or with the rear at any other ride height, as long as they permit enough suspension travel before a little nonlinearity creeps in.

The only geometric angular requirement is that the inclinations of the two links must be equal and opposite. Setting them horizontal at static ride height is only a special (and convenient) case of this. Think about this for a moment . . . if you set them perfectly horizontally with no driver or weight equivalent in the car, what do you suppose happens when the driver does get in?


Norm

 

[ArizonaGT]

Norm--the "static" alignment makes sense; thanks for the explanation.

 

[Gray Ghost GT]

Check Page #12 on the installation instructions document (LINK)

 

[ArizonaGT]

Check Page #12 on the installation instructions document (LINK)

Downloaded that earlier; thank you for providing, btw.

 

[barbaro]

Here are the facts:

(1) Which company designed & marketed the first watts link for the S197? Fays2 or Cortex, and for more Mustang platforms?

Answer: Fays2

(2) Which company uses a chassis mounted design, which provides superior performance to the differential mounted design?

Answer: Fays2

(3) Which company sells their watts link for $350 less than their competition while maintaining a proven performance record?

Answer: Fays2

(4) Which company has been involved in road racing longer with their watts link with vintage Mustangs, SN95 and the S197?

Answer: Fays2

(5) Which company provides a watts link solution for S197 Convertibles? The competition often only supports Coupe models.

Answer: Fays2

(6) Which watts link design allows you to race in more series due to strict rules because you're not modifying the differential?

Answer: Fays2

(7) Which company allows you to use OEM or Ford Racing Differential covers? Competition adds more weight to the differential.

Answer: Fays2

(8) Which company copied a design vs. being the first with an original design? Knock-off typically don't understand the science.

Answer: Cortex (Thanks to Griggs)

(9) Which company adds more unsprung weight (20 lbs.) to the live axle; degrading handling performance of the suspension?

Answer: Cortex

You see where this is going? Oh, wait - the most important question for a watts link:

(10) Which company produces a shiny beautiful elegant watts link "super model"?

Answer: Apparently Cortex....

Have you noticed the Fays2 haters can't explain why in technical terms why they think their $$Cortex$$ choice is better for the road courses vs. a photo shoot on jack standards? Every rumor about the Fays2 watts link was squashed, e.g., noise, exhaust, sway bars, racing and the list goes on. Stick to the facts. Yes, it is possible to say the Fays2 works better if you understand suspension dynamics of a chassis vs. differential mounted watts link. It's Physics and Geometry.

The Cortex places the pivot on the differential. Therefore the motion of the axle must move in a straight line relative to the body of the car, e.g., if the car is leaning, so will the direction of bump travel. Also, the relationship between the roll center and the center of gravity changes during bumps. This is also not good.

The Fays2 places the pivot on the chassis, which allows the axle to move straight up and down relative to the surface, no matter how far over the body is leaning in the turns and esses. The cars roll center and center of gravity do not change in relation to each other. This relationship is known as roll couple and has a great effect on handling under cornering, braking and acceleration.

It's obvious that the Cortex fan doesn't understand these suspension dynamic details (except to say something like, "It's race") because he even states in his post:



Which watts link is probably the worst with regards to design...Whiteline, because its a "single sheer" system that's been known to fail as have other products that they eventually Recalled, such as their Rear Upper Control Arm based on poor engineering design & manufacturing in an effort to be the cheapest on the market.

You say that the issue of noise with Fays II has been disproved. It has not. It is a recurring issue that has been noticed by more than just me. Who cares who was first? Ford was one of the first car makers. Does that make them the best? And this focus on who copied who. I don't give a toss. The Watts link comes in a thousand different iterations depending on the application. And there are only so many that will work in a Mustang so of course different brand of Watts links are going to share similar characteristics. There is nothing new under the sun when it comes to Watts Links. And my experience is that guys with track dedicated cars have a tolerance for nvh that is not shared by the public at large. I believe the Fays II probably does what it is supposed to do but it looks like it was designed by a couple of drunk monkeys.

 

[neema]

If you mean the two lateral links of the Watts link, you don't have to touch their inclinations once you've set them the first time. There is nothing 'sacred' about them being horizontal with the car at rest or with the rear at any other ride height, as long as they permit enough suspension travel before a little nonlinearity creeps in.

The only geometric angular requirement is that the inclinations of the two links must be equal and opposite. Setting them horizontal at static ride height is only a special (and convenient) case of this. Think about this for a moment . . . if you set them perfectly horizontally with no driver or weight equivalent in the car, what do you suppose happens when the driver does get in?


Norm

Got it. I was assuming (without really thinking) that if the propeller is moved up or down, that the length of the lateral links would need to change as well. It seems like once they're set to the desired length to center the axle, the propeller's position is what compensates/adjusts for movement. I think I just had a "duh" moment.

Thanks Norm

 

[Gray Ghost GT]

There are three members in this thread alone that use the Fays2 (vs. those that have no experience with the product) that commented on their years of personal experiences to include the "noise or no noise" issue; results are:

Gray Ghost GT - No Noise
JesseW. - No Noise
Whiskey11 - No Noise

Far from a "recurring issue". In fact, for the small % of users that may experience some NVH, its often due to improper installation. No noise means no noise, not "tolerance for low NVH". I welcome the opportunity to compare my Fays2 to anyone's Cortex setup to check NVH. However, I do find the continuous references to "monkeys" hilarious as the layman's perspective on suspension knowledge.

Fays2 is #1 among chassis mounted watts links and Cortex appears to be #1 among differential mounted watts links. Two designs to provide a similar function to improve handling in a performance environment. The Cortex ($995) looks like a quality system built by an engineer that has a great reputation just as the Fays2 ($650) product was engineered. Two good choices, but lets stick to the facts.

 

[NoTicket]

Man after uninstalling my watts link and putting back the phb... I have never been convinced more that a watts link is the way to go. The car rides significantly worse over bumps. The rear feels oddly stiff. The difference in going back is even more stark than when going from the phb to the watts. Oh well. If I end up keeping the car long enough I will probably put a fays2 on it.

 

[a50cobra]

There are three members in this thread alone that use the Fays2 (vs. those that have no experience with the product) that commented on their years of personal experiences to include the "noise or no noise" issue; results are:

Gray Ghost GT - No Noise
JesseW. - No Noise
Whiskey11 - No Noise

You can add me to that list. I've had mine for a year and a half and no noise. It's a DD that sees lots of miles and I beat up on her fairly often too.

And Ghost, I also prefer the one notch below neutral prop position. But I think that has a lot to do with 1) suspension/tires/sway-bar set up and 2) driver preference. Just another

 

[Whiskey11]

You can add me to that list. I've had mine for a year and a half and no noise. It's a DD that sees lots of miles and I beat up on her fairly often too.

And Ghost, I also prefer the one notch below neutral prop position. But I think that has a lot to do with 1) suspension/tires/sway-bar set up and 2) driver preference. Just another

It certainly does. I've tried just about every position but the ones just above and below neutral... Right now it is all the way up on my car. Strano bar up full stiff up front and Strano 25mm rear bar in the middle position out back. 440lbs/in springs up front, 200lbs/in springs out back, torque arm and street tires and the car is a touch loose. I'm willing to bet that dropping the rear bar back down to the lowest position would result in a better handling car and is probably something I will do until I decide whether or not I will keep the 09 or sell it and get an S550. S550 has to make the weight cut before I'll consider swapping though...

 

[ArizonaGT]

Well I just ordered a Fays2.

 

[Roadracer350]

We're still on this?!?!

 

[B2B]

While researching for a watts link, there seems to be a lot of confusion about if the Cortex watts link requires welding or not. I finally emailed Filip Trojanek in December and here is his reply:

"We are only selling the "bolt-in" version now since the weld-in version was phased out of production. The bolt in version can just as easily be welded in as the original design through. Anything welded will be more permanent and typically stronger than if it is only bolted in however the bolted design has been proven on Boss 302S World Challenge Mustangs running Pirelli slicks. The main benefit to welding is: No need to ever check or retorque bolts. That is why we recommend it in the installation instructions for true race cars. The good news is that the bolt-in design is significantly stronger than the competitors. Ford Racing selected our watts for the Boss 302S World Challenge racing program because it had the most robust and reliable design, allowed the most adjustment, and weighed less than the competition."

After talking with JG @ Chicane23, I decided to go ahead and ordered the Street version of the Cortex watts link.

I'm very impressed with the simplicity of the whole watts link and the stout/clean construction of all the components. Since I've never seen detailed pictures of the no-welding driver side tower and bushings used in the "Street" version of the kit, I thought I'd snap a few pictures for those who are curious as well.

I didn't get very far with the installation this weekend so I'll add additional pictures as it goes together.

Francis

 

[Pentalab]

My problem with the fays + steeda units is the use of the axle clamps. Some folks have reported that the axle clamps shifted on the axle..and both shifted as much as 1/4" or more. Giant U clamps are not the ideal clamping method....and at least 2-3 should be used on each end. U clamps don't have any surface area vs a clamping block. They really should be welded to the axles.

The griggs /cortex /WL version articulates on the diff cover /spider /football..no axle clamps required.

My other problem with the fays /steeda version is the huge truss that spans the width of the car...... whose only purpose is to support the articulation point. The cortex /griggs /WL doesn't require it.

I have the WL version on my 2010... but it's a street car only. I had the eaton Tru-trac differential installed the same day. Between the tru-trac and WL watts link.... it's a night and day difference for street use. Watts links are superb for street use. On a road course you know that the inside of corner #3 is bumpy..and ditto with outside of corner #5 etc, etc. I drive 10 miles north of home, and I have no clue what I'm going to hit this week.


Prior to that, I had replaced the ford oem PHB with the BMR on car adjustable PHB + mating BMR PHB upper brace. The ford oem upper brace is pure junk..3 x sided stamped steel. One fellow cut the end off his oem PHB... and out poured a ton of sand! The BMR PHB is a superb unit..easy to center the axle..and ditto with the BMR rect tubed upper PHB brace.

I noticed that on all 05-14 cars.. (including GT-500) that the axle is offset towards the drivers side by typ 3/8" to 5/8".

The WL watts link has given me zero problems so far..... but I haven't beat on it either. With the oem PHB + oem traction lok diff, the car doesn't inspire confidence..esp at night.

Jimbo

 

[Gray Ghost GT]

My problem with the fays + steeda units is the use of the axle clamps. They really should be welded to the axles.

My other problem with the fays /steeda version is the huge truss that spans the width of the car...... whose only purpose is to support the articulation point.

I had my Fays2 axle clamps tack welded to prevent them from shifting - easy enough to do during the installation process.

What you identify as a "problem" (truss that supports the articulation point) is actually the significant benefit of the design over a differential mounted unit, which is explained in this thread.

 

[Norm Peterson]

My problem with the fays + steeda units is the use of the axle clamps. Some folks have reported that the axle clamps shifted on the axle..and both shifted as much as 1/4" or more. Giant U clamps are not the ideal clamping method....and at least 2-3 should be used on each end. U clamps don't have any surface area vs a clamping block. They really should be welded to the axles.

Ideally, yes. The same can be said for the chassis side brackets for a diff-football Watts link although the amount of unexpected movement would be much lower (being limited by bolt to hole clearances).


Now I need to set the record straight on a few things . . .

My other problem with the fays /steeda version is the huge truss that spans the width of the car...... whose only purpose is to support the articulation point. The cortex /griggs /WL doesn't require it.

The two different Watts link configurations accomplish a slightly different 'balance' between certain geometric effects while they are locating the axle laterally, so the actual as-installed location of the articulation point does have some importance.

Prior to that, I had replaced the ford oem PHB with the BMR on car adjustable PHB + mating BMR PHB upper brace. The ford oem upper brace is pure junk..3 x sided stamped steel.

It may look like "junk" to you and to people not familiar with structural engineering, so let me tell you that the PHB brace is never intentionally loaded by anything the car does in the flimsy-looking directions that have grabbed your attention. If it passes Ford's durability criteria for what's mostly just tension or compression, don't get worried because you might be able to bend or twist it with your bare hands or with a small wrench, or that it would make for a piss-poor tiedown attachment point.

One fellow cut the end off his oem PHB... and out poured a ton of sand!

It's there for a reason. But if Ford had specified a channel-section PHB like the 3rd and 4th gen F-body cars used people would still be complaining that it was "flimsy" simply because it wasn't tubular. Funny, but even those PHBs worked well enough even with R-comp tires at autocross.


Norm
civil-structural guy (retired)

 

[ArizonaGT]

Norm: Thank you for your various contributions in this thread and this subforum in general. These objective/functionally-minded posts help keep my sanity while reading everybody's armchair racing opinion on what is amazing and what is crap.

 

[sheizasosay]

Norm: Thank you for your various contributions in this thread and this subforum in general. These objective/functionally-minded posts help keep my sanity while reading everybody's armchair racing opinion on what is amazing and what is crap.

+1

I look forward to his posts.