cortex watts link

[NoTicket]

I put a Watts Link on my car and it killed my mother, and raped my father. But at least my car now drives exactly like it has an IRS, I even beat an e92 PWC GTS car! I have no other mods!

 

[Gray Ghost GT]

Checkout this statement from the "Official Griggs Racing Blog" as it looks like they compared performance between the PHB and Watts Link on the same car with the same driver at the same track to draw this conclusion:

"....In fact we have found that our tuneable watts linkage lends itself to consistently Quicker lap times than a Panhard Bar. The reason for this is because, unlike a Panhard Bar, both right and left cornering characteristics are identical. This is due to the fixed roll center relative to ground of the GR40 Watts link...."

Interesting video:

 

[kcbrown]

Checkout this statement from the "Official Griggs Racing Blog" as it looks like they compared performance between the PHB and Watts Link on the same car with the same driver at the same track to draw this conclusion:

"....In fact we have found that our tuneable watts linkage lends itself to consistently Quicker lap times than a Panhard Bar. The reason for this is because, unlike a Panhard Bar, both right and left cornering characteristics are identical. This is due to the fixed roll center relative to ground of the GR40 Watts link...."

I wonder how much quicker we're talking about (I see no mention of actual lap times), and whether there were any roll center differences between the two (I suppose, when talking about the PHB, you'd be talking about the average roll center, which is probably the roll center at ride height).

 

[SoundGuyDave]

Oh, believe me, I understand how a Watts works, and I understand how a PHB works... The Griggs blog thing just made me chuckle, in so many spots...

The only hard data that they threw out there was that the GR40SS kit (springs, dampers, bars, PHB, etc.) dropped a stock S197 lap time by 6 seconds. Then they go on to claim that swapping to a WL will drop another second. THAT is a data point that should be readily apparent to any seasoned driver, yet the "mystery" still remains. If it REALLY dropped a full second, there would be SO many examples of that kind of time drop floating around, but there just aren't. If it was THAT obvious, everybody on track with a PHB would just be getting KILLED by Watts cars, but it's simply not happening. Think about it: given a 2:30 lap pace, and given a 40-minute sprint race, that would equate to a SIXTEEN SECOND ADVANTAGE at the checkered flag. Is anybody seeing that kind of disparity?

The Griggs post is at best thinly-veiled marketing, explaining why their version of the improved moustrap is better than all the other improved mousetraps out there. According to their blog, the BIGGEST factor involved with their diff-mounted WL is that the roll center does NOT migrate relative to ground level when the suspension pitches. According to them, that means that the Fays2 is actually MORE useless than a PHB, since the PHB RCH migration is only 50% of the body motion, while the Fays2 is 100%. Since there are apparently an equal number of Fays2 supporters to Griggs/Cortex supporters, or at least equally vocal, that calls into question Griggs' conclusions...

DATA!!! SOMEBODY POST UP SOME DAMN DATA!!!

 

[Pentalab]

I think these might be good examples of when you would not want to buy a watts link:

* Daily Driver
* Drag Racing
* Oval Track
* HPDE 1-2 on a Road Course

Examples of when you would want a watts link: quick lateral transitions with some skill:

* Autocross
* HPDE 3-4 on a Road Course
* Time Trials

Interesting to note that JDM engineering no longer sells either the fays2 or the steeda watts links. They now only sell the WL version. JDM claims that they have had nothing but problems with the fays2 and steeda units.
JDM also claims the WL watts link will result in straighter launches on the drag strip.

As a side note, my own WL watts link was installed the SAME day as my eaton Tru-trac. My perceived improvement in handling..as in asap, right after install, may well be the combined effects of both the watts link + tru-trac. However, several other's, like DiMora, already had the tru-trac previously installed. DiMora then installed the WL watts link..and he too saw a huge improvement in handling. DiMora sez the WL-watts link made as much or more improvement than the ton of steeda suspension mods etc that he had previously done.

In my case, yes, the car launches straighter when the light goes green..but again, part of that effect may well have been the COMBINED result of the WL watts link + tru-trac.

On another note, imo, any PHB will work better if the car has been lowered from stock ride height. Reason is, the PHB is now at a slightly flatter angle. (more parallel to the ground). I believe the RC has been lowered a bit.

Steeda now has an interesting PHB ( and mating brace combo). It's a PHB, that has adjustable RC. Both ends of the PHB can be adjusted up /down. IE: the PHB can now be a lot flatter than stock PHB.. ( even with the car lowered). http://www.steeda.com/store/steeda-adjustable-panhard-brace-bar-combo-555-2553/

I'm just going by my DD experiences here.... but the tru-trac + WL watts link combo made a substantial improvement in handling. Previously I had installed a steeda STB over the eng..and also a steeda rear STB, welded in the trunk. Plus bolted + welded steeda 3 point sub frame connectors and also a pair of steeda front sway bar braces. Also installed was BMR LCA's...and also BMR lca relocate brackets ..and an adjustable BMR UCA + UCA mount. Also installed a BMR A arm support brace. While on a roll.. I installed a BMR rear tunnel brace + mating DS safety loop..and also a DSS-DS. ( a ton of other stuff done, SS brake lines, ATE-blue, air cooled front discs, eng mods, LT's etc.). Steeda strut mounts added ( now I have 1 deg of camber).

Even with all of that previously done, the combo WL-watts link + tru-trac is a killer combo for aggressive street use. I could see the effects immediately.

Jimbo

 

[NoTicket]

Jesus Christ... I think Dave's fingers are going to fall off responding to that.

 

[ArizonaGT]

Jesus Christ... I think Dave's fingers are going to fall off responding to that.

 

[ArizonaGT]

This thread:

 

[NoTicket]

Well, regardless of how much I try there is no way I can gather the thorough info that Dave wants. I have however put some money toward it. I purchased a Maximum Motorsports rod ended phb and will be putting that on this weekend. I will see how it works. Of course I do not have the equipment necessary to provide anything other than seat of the pants analysis. However, there is a chance that at some point this year I could perform a proper before and after test.

My curiosity has overcome my desire not to spend $159.

 

[SoundGuyDave]

Dear Jimbo:



Probably wouldn't have happened if he had a Watts Link... As we all know, it does solve all evils...

Seriously, though... THIS IS SPARTA!!!! I mean, this is the corner-carvers sub-forum, where we don't give two flying shits what makes a drag car launch straighter or what the dopes at JDM are selling this month.

Also, just to set the record straight, if ANYBODY is driving hard enough to properly judge the grip potential of a suspension component while on a public street, they are in need of a serious discussion with a member of law enforcement, and possibly a very large cell-mate by the name of "Bubba." The knucklehead drag racers already account for far too high of a body count on an annual basis, the last thing our little corner-carving crew needs is to add to that number. Unfortunately, far, far too many people (ahem, Paul Walker crash?) manage to "run out of talent" and take somebody with them while driving in a "spirited" manner on a public street.

When you're on a track, EVERYBODY is going the same direction (for the most part!), EVERYBODY is working off the same sheet of rules and etiquette, and everybody (hopefully!) has their head up out of the car looking for potential problems ahead... On the street, while you just nailed that perfect apex in a residential area, a four-year old child ran out from behind a parked car after his/her ball...

The vast majority of us here push our cars hard, sometimes past the limit, but we do it in controlled circumstances, like a road course or an autocross track.

Sir, based on your last post, I think you're starting to catch on to the vibe we seem to have over in our little corner of the interwebz, and I hope that this post might help to cement some of that in your mind. PLEASE eliminate the concept of "aggressive street use" from your worldview, and get yourself and your car out to a local track. I have no idea what area you're from, but go to NASAproracing.com, and look up your local region to get scheduling for the next event.

Yes, we tend to be a bit analytical and may seem mired in the engineering and modeling aspects of the hardware we use, but the underpinnings of our chosen form of motorsport are a lot less forgiving of failures (ever had a control arm fail on you going into a braking zone at 140mph three feet from a concrete wall?), and as a result, we tend to really scrutinize any kind of marketing BS that we may be whacked upside the head with. Kind of like the Jesuits, we question, question, question. Just because the interwebz said so, simply isn't good enough for us. We demand proof of a claim, not just the claim itself. Particularly if the claim flies in the face of anticipated results based on engineering and modeling... Around here, if you make a statement, be prepared to back up that statement with some form of evidentiary support, or be prepared to be doused in gasoline and lit aflame (hyperbole). None of us are saying not to contribute, but be sure of your facts before you post unsubstantiated claims. At least here, we're trying not to perpetuate the typical internet drivel and misinformation that seems rampant elsewhere.

Okay, I'm done.

 

[SoundGuyDave]

Well, regardless of how much I try there is no way I can gather the thorough info that Dave wants. I have however put some money toward it. I purchased a Maximum Motorsports rod ended phb and will be putting that on this weekend. I will see how it works. Of course I do not have the equipment necessary to provide anything other than seat of the pants analysis. However, there is a chance that at some point this year I could perform a proper before and after test.

My curiosity has overcome my desire not to spend $159.

All that I will ask of you is that you set the RCH on your Watts to match that of the PHB before comparing the two. That will eliminate at least that as a variable, and RCH is a MAJOR variable! Assuming you're testing on a closed-course (as opposed to an Autocross rally-stage style layout), where there is a single start/finish point, you could do some basic data acquisition with a smart-phone ap, like Harry's lap timer. Run a session with the Watts, log your lap times (and g-forces if the ap offers that), swap in the PHB and brace, then repeat, and compare the numbers. Ideally it'll be at a track where you have some familiarity and comfort, and not a new-to-you venue, where you're constantly dropping lap times as you get into the swing of things.

I'm not saying that a PHB is better than a Watts, all I'm saying is that absent any RCH change I doubt that there will be any real effect on drivability, lap times, or rear lat-G capability switching between the two.

What part of the world are you in, anyway?

 

[Mach2burnout]

There isn't any. The difference is seat of the pants feel and not actually any faster. If the driver doesn't feel uncomfortable with the little extra movement you get with the PHB or if he prefers it then he will not be faster with WL. Many, suspension part changes are about making the driver comfortable. I've seen guys be super fast in one car, take him out and put him in a different car running comparable lap times with a different setup and he's not near as fast. The WL IMO is one of those components that is more about making the driver feel comfortable and confident than actual speed improvement.


Sent from iPhone

 

[Gray Ghost GT]

Interesting to note that JDM engineering no longer sells either the fays2 or the steeda watts links. They now only sell the WL version. JDM claims that they have had nothing but problems with the fays2 and steeda units. JDM also claims the WL watts link will result in straighter launches on the drag strip.

Actually not that interesting from a technical or engineering perspective. Profit margin had more to do with the JDM decision to sell one product vs. another. One simple statistic is how many design flaws and product recalls did Whiteline have with their suspension products (LCA, UCA and watts link) vs. Fays2/Steeda? JDM claims in this instance are pure marketing BS; especially with "straighter launches on the drag strip". LOL! Without a set of objective data to compare the various alternatives, you have to rely on design geometry, physics and logic to compare and contrast how one option performs vs. another in a road course environment.

 

[2008 V6]

My God - 11 pages

 

[Conekiller]

I guess I am in minority since I didn't have a life changing moment after installing my Fays2 watts link. In street driving I can't tell a difference in my fays2 equiped car and my roommates phb equiped car. In autocross I imediately noticed a difference in slaloms or similar elements with the rear being more predictable. That probably had a net effect of quicker times from a driver confidence factor but beyond that and roll center adjustability I'm not sure how much it helps. Outside of those situations I would have difficulty saying there's any measurable difference or if its just perception of wanting there to be a difference.

I would like to say the rear felt less "nervous" over road imperfections after I installed the watts link, but again can't be sure that wasn't me just wanting it to feel different. Would I do a watts again? In an instant if autocrossing but not for street use and I don't have any experience with open tracking to offer an informed opinion there.

 

[Norm Peterson]

In my case, yes, the car launches straighter when the light goes green..but again, part of that effect may well have been the COMBINED result of the WL watts link + tru-trac.

I'm struggling to find even an indirect link between just having a Watts link and getting a straighter launch.

Without much success, unless you also did one or more of the following:

* Located the Watts link main pivot at a different height than the midpoint height of the PHB you removed
* Changed the rear ride height via different springs or other suspension ride height adjustment methods
* Revised the LCA inclination with relo bracket settings
* Stiffened the rear springs or sta-bar

Doing any of those things does have the potential for providing a straighter launch, and none of them have anything specifically Watts link-related other than the strictly incidental setting of the pivot height. An adjustable height PHB such as the Steeda piece would provide similar improvement by choosing a similarly incidental height setting.


Norm

 

[NoTicket]

All that I will ask of you is that you set the RCH on your Watts to match that of the PHB before comparing the two. That will eliminate at least that as a variable, and RCH is a MAJOR variable! Assuming you're testing on a closed-course (as opposed to an Autocross rally-stage style layout), where there is a single start/finish point, you could do some basic data acquisition with a smart-phone ap, like Harry's lap timer. Run a session with the Watts, log your lap times (and g-forces if the ap offers that), swap in the PHB and brace, then repeat, and compare the numbers. Ideally it'll be at a track where you have some familiarity and comfort, and not a new-to-you venue, where you're constantly dropping lap times as you get into the swing of things.

I'm not saying that a PHB is better than a Watts, all I'm saying is that absent any RCH change I doubt that there will be any real effect on drivability, lap times, or rear lat-G capability switching between the two.

What part of the world are you in, anyway?

I'm in San Jose, CA.

I will do my best to eliminate any other variables from the equation. I will not be doing the comparison at Laguna Seca (where I will be next week) because I have never been there in this car before. I will likely do some comparison in April when I head to Thunderhill.

I will be using Harry's Lap Timer because it is pretty much the best. What I would really like to do is bolt a gyroscope to the bottom of the trunk and measure body movement on the street over some bumps, hitting them straight and hitting some others leaned over. Then also run the same logging at the track. This would give an interesting data point regarding the actual measurable lateral forces introduced when hitting bumps with a PHB vs. a Watts. If I can manage to get an app that will do this data logging I can at least do the street test and add a bit of info to the whole "ride quality" question.

To be clear, if it turns out that the PHB is not very different than the Watts I will be very happy. It means I can have a super simple, super light bar out back instead of all of the Watts complexity.

 

[Pentalab]

Points well taken Dave. I'm not arguing with you..esp with street use. However my 2010 GT.....bone stock handled like crap...they all do. Stand on the brakes and front end nose dives. Back end rises sky high. Floor it at a green light and front end lifts like crazy..and back end squats. There is NO camber adjustment on any 05-14 car. Brakes are semi junk. Throttle response left a lot to be desired..and the list goes on and on. Too much body roll, + vague turn in. It's ok for cruising in a straight line on the hwy at 50-60 mph....and that's about it.

Bone stock, the car would be a dead loss on any track or autocross event. At least with the suspension mods I have done so far, plus brakes etc, the car now inspires some confidence. I feel that alone makes for a safer street driven car. Stock, it really is crap.

Ok, now I'm semi set up for this summer's auto cross local events. They use portions of the infield on our local .4 mile oval track. It's not a hp track, judging by all the corners and cones. A 3850 lb mustang will be a trick to get around it..quickly. I'm expecting any 20 yr old kid in his honda civic to clean my clock. It appears the overall layout is optimized for ricers.

I still contend that the WL watts link + eaton tru trac combo is well worth it for a DD....vs oem PHB + differential. If folks think Ford 'got it right' with the oem PHB setup... well they didn't. Drove me nuts with the axle sticking out almost 3/4" towards the driver's side. My camber, stock... was -1.1 deg on pass side.....and -1.4 deg on the driver's side. Bone stock, these cars are not worth taking to your local track....unless you want to prove it's obvious shortcomings.

As far as parts failing... BMR has had serious recent issues with A arms, K members and other stuff... welds breaking, and metal fatigue. Roush had the welds breaking on its front shocks just a few years back. No one is impervious..unless its tested really good.

Baffles me how Terry Fair beats on all his WL equipment..yet never reports any failures. I highly suspect being a WL dealer, we would never find out anyway.... but I may be wrong. Do any of these co's X ray their welds....I doubt it. If 4130 chromolly is used.... is it heat treated..or not ? Big difference in yield strength, 70 ksi vs 120 ksi. Normal deal is to cut, drill, bend and weld the piece ..1st...then heat treat the finished product..dead last. Then paint it. DOM is typ between 75-91 ksi..and can't be heat treated.

I'll leave it at that....and just listen from here on in.

Jimbo

 

[Pentalab]

I'm struggling to find even an indirect link between just having a Watts link and getting a straighter launch.

Without much success, unless you also did one or more of the following:

* Located the Watts link main pivot at a different height than the midpoint height of the PHB you removed
* Changed the rear ride height via different springs or other suspension ride height adjustment methods
* Revised the LCA inclination with relo bracket settings
* Stiffened the rear springs or sta-bar

Doing any of those things does have the potential for providing a straighter launch, and none of them have anything specifically Watts link-related other than the strictly incidental setting of the pivot height. An adjustable height PHB such as the Steeda piece would provide similar improvement by choosing a similarly incidental height setting.


Norm

## I actually did everything on your list above. Ok, what are you calling the midpoint height of the PHB ? If it's 1/2 way along the PHB ..that point is well above the midpoint of the center of the differential. The center propeller bolt on the WL watts link is aprx slightly below the center of the diff casing.

If that is the case (I may well be incorrect).... then the WL center pivot point is indeed lower than the midpoint length of the phb. That alone may well account for my perceived notion of "better handling".

The RC adjustable steeda PHB may be the ideal ticket....plus it's overall length can be tweaked....to center the axle.

Jimbo

 

[2008 V6]

DOM is typ between 75-91 ksi..and can't be heat treated.

Jimbo

It can be and should be annealed especially when your life is on the line and you didn’t weld it yourself.

X-ray is advisable but have you ever tried to read and x-ray of a small circumference weld – very difficult and several shots needed.

In another post I expressed my opinion on Watts / Vs Panhard bar debate.
The only disadvantage to a properly designed Panhard bar is ground clearance (Running the length of the entire axle as opposed to half with a watts). One other variable I hadn’t thought of until now is bar deflection / bending under load. Causing a possible slight spring affect. Slim possibility but stile there. One bar twice the length of two separate bars will deflect more than the sum of the two given the same gauge & size of tubing. WHHHO WWWW– will this also open another debate about bar deflection?