Cortex Torque Arm Racechrono Track Review

[barbaro]

Once again, the thread begins to get technical again and you have to take a poop in it.



Statements like this discredit your experience and opinions. It doesn't matter how good your suspension is, it comes down to 4 contact patches at the road when you are trying to drive fast.

First I started this thread. Second I have driven and tracked the very part this thread is about. Third, the thread is getting technical again? Hypothetical talk about the possibility of NVH in a Torque arm with little reference to experience with the unit is edifying to you? This is why I don't get some of you. In the Cortex Unit, it is a non-issue or at the very least such a minor issue as to not merit this much analysis by people who have never used it. This should not be called Corner Carvers but "Hypothetical Problems and Issues in Parts we don't have and Will probably not use forum." Sounds like the title of a bad college class.

You and yours parse everything I say on the lookout for hyperbole exaggeration, understatement, the slightest inaccuracy, or incorrect verbiage in order to imply the most negative connotation. Always coming down to the ultimate conclusion which is you don't know what you are talking about, you are an idiot, STFU etc . . . What I said does not discredit me or anyone else.

That is your hyperbole, exaggeration and overstatement. Wouldn't it be nice if you had just a smidgen of experience with the equipment? Wouldn't it be nice if you had actually driven the car before and after? Or any similarly equipped car before and after. Wouldn't it be nice if you had driven such a car at the track( I have), On a mountain road (I have), on the street. (I have) That way you could opine with credibility about NVH, handling characteristics, pitch and yaw and bodyroll, antisquat, quadratic equations, E=MC squared etc . . . but you don't have that. What you do have is a small mob that largely has the same experience as you, none.

 

[kcbrown]

Aftermarket upper control arms for S197's are notorious for clunking and transferring NVH into the chassis. I have personally experienced this as have others who have written about it. That is why I am not a fan of aftermarket Upper Control Arms. (See Terry Fair Upper Control Arms comments on his thread) there may be some good ones but I have tried both Steed and UPC and they both harshened my ride and transmitted noise and vibration into the cabin. Whether you define any part of that as resonance or not I don't know.

I wouldn't define it as resonance.

Resonance is a specific physical phenomenon which refers to a physical object's vibration increasing well beyond what it would normally be as a result of the object being "in tune", as it were, with the frequency of the vibration it's being subject to.

An example is when a wine glass shatters when subjected to a tone of a certain frequency. This happens because the glass vibrates "in tune with" the tone, and so the energy of the tone essentially reinforces the vibration that's already happening within the glass.

Most resonance doesn't happen to destruction in the way it does with the shattering glass, but you can still get a lot of unwanted effects from it. On the other hand, you can also engineer a system to actually take advantage of it. Resonance isn't an effect that is limited to motion, it also happens in electronics, and it is used to good advantage in the design of radio receivers. When you change the tuner in your receiver, you are literally changing the resonance frequency of the tuner's circuitry. That's a good example of a system being engineered to take advantage of resonance.

The issue of resonance as you define it has arisen for me with the use of a one piece drive shaft on a previous car, but not with the Cortex Torque Arm.

That's good to know. I wouldn't expect there to be many changes that one could make to the car that would have an effect on the resonance response of the torque arm or to the range of vibrational frequencies to which it is subject. If the torque arm doesn't seem to exhibit any real resonance on its own over a wide speed range, engine RPM range, and range of road conditions, then I would think that its set of resonance frequencies is likely to lie outside of what the car is going to generate. And that's very good news, indeed.



By the way, while you might not be familiar with some of the engineering terminology being bandied about and may not have any real knowledge of engineering of any kind, that doesn't mean you can't learn. I can certainly understand, based on some of the feedback you've gotten here, why you might hesitate to try. My personal feeling on the subject is that some here have perhaps been a little overly critical and that you've perhaps been a little too sensitive to that criticism. And the end result is overreaction on both sides. I think that ends up being a disservice to everyone.

What I'm saying is that if you're willing to hang in there, I'll be happy to attempt to explain things to the best of my abilities, in roughly the same way I explained the concept of resonance above. And I'm hopeful that others here will be just as willing to do the same. While my understanding of suspension engineering is currently in its infancy and it's been a couple of decades or so since I've been involved in any engineering (and then it was only at an academic level, as I was in the electrical engineering curriculum at college at the time prior to switching to computer science), I've never stopped looking at things from the perspective of an engineer and have always enjoyed physics (which is at the foundation of all this). It's one of the reasons I'm actually quite excited to get back into the process of suspension modification (though the real reason is, of course, the fun I expect to have on the track!). There's nothing quite as edifying as analyzing a problem, seeing a potential solution, trying that solution, and seeing it work.

 

[barbaro]

Rest assured Norm, I have not forgotten you.

You have gone to great pains to parse all my statements. Rhetorically, that is wise because it allows you evaluate statements out of context for your purposes. You examine the tree and miss the forest.

This fuss about body roll. My car corners flatter since the installation of the torque arm. Everyone I know who has one says the same thing. Now whether that is mainly attributable to less pitch or yaw or roll I could not tell you subjectively. But you can tell me and I don't dispute you. But the effect is the car is flatter going in and coming out of turns. I leave it to you to define it further. I think I have explained myself several times on this issue.

My math background ended at high school calculus in which I got an A As I remember it. I had one year of physics at UCLA and I got a B both semesters. I took high school Shop and I can accomplish most repairs on my car if I have to. I don't work as much on my car anymore because people pay me a lot of money for my time and advice and it is not cost effective for me to do it. I went to reputable universities. I got good grades. That being said, I half understand you. I acknowledge the importance of thinking things out from an engineering perspective. It is essential. I do appreciate your knowledge. I have been edified by several of your posts on other forums.

But for many here including you, this thread has become personal. And you are using your background not to fairly reflect on the subject at hand but to slam me by parsing out any hint of unorthodoxy, innacuracy, over or understatement, with the full knowledge that you have the support of some other ossified 1000 plus posters on this forum.

What is irritating you and others is that I won't back down. I persist in my opinion despite the "math" and the opinions of several others who have not used the parts I am posting about. I do this only when I know what I am talking about. When it comes to what these parts do, what their practical effect is, I know what I am talking about. As to why I defer to Filip and Griggs and the other engineers and race teams who have tested the equipment. I am not going to opine on that because as to that, I am admittedly out of my element.

You and others are arguing with my subjective experience. It is ludicrous. For instance, can you describe an orgasm Norm? Let's supposed you tried and you used a word that to me did not reflect the true experience of an orgasm. Would it be righteous for me to parse that word and infer that you have never experienced an orgasm? Further, let us suppose that you had an imperfect knowledge of erectile tissue and the location of your seminal vesicles would that justify me denigrating your experience of your hard on or your ejaculation? Should I infer that you never had a hard on or shot your wad?

So this focus on what you know and I don't lends nothing to the evaluation of the subjective experience. I am not incapable of evaluating "technical" information. I suppose in fact that I am better than most but do not mistake the understanding of erectile tissue with the glorious reality of a Hard On. They are not the same thing.

 

[barbaro]

I wouldn't define it as resonance.

Resonance is a specific physical phenomenon which refers to a physical object's vibration increasing well beyond what it would normally be as a result of the object being "in tune", as it were, with the frequency of the vibration it's being subject to.

An example is when a wine glass shatters when subjected to a tone of a certain frequency. This happens because the glass vibrates "in tune with" the tone, and so the energy of the tone essentially reinforces the vibration that's already happening within the glass.

Most resonance doesn't happen to destruction in the way it does with the shattering glass, but you can still get a lot of unwanted effects from it. On the other hand, you can also engineer a system to actually take advantage of it. Resonance isn't an effect that is limited to motion, it also happens in electronics, and it is used to good advantage in the design of radio receivers. When you change the tuner in your receiver, you are literally changing the resonance frequency of the tuner's circuitry.


That's good to know. I wouldn't expect there to be many changes that one could make to the car that would have an effect on the resonance response of the torque arm or to the range of vibrational frequencies to which it is subject. If the torque arm doesn't seem to exhibit any real resonance on its own over a wide speed range, engine RPM range, and range of road conditions, then I would think that its set of resonance frequencies is likely to lie outside of what the car is going to generate. And that's very good news, indeed.



By the way, while you might not be familiar with some of the engineering terminology being bandied about and may not have any real knowledge of engineering of any kind, that doesn't mean you can't learn. I can certainly understand, based on some of the feedback you've gotten here, why you might hesitate to try. My personal feeling on the subject is that some here have perhaps been a little overly critical and that you've perhaps been a little too sensitive to that criticism. And the end result is overreaction on both sides. I think that ends up being a disservice to everyone.

What I'm saying is that if you're willing to hang in there, I'll be happy to attempt to explain things to the best of my abilities, in roughly the same way I explained the concept of resonance above. And I'm hopeful that others here will be just as willing to do the same. While my understanding of suspension engineering is currently in its infancy and it's been a couple of decades or so since I've been involved in any engineering (and then it was only at an academic level, as I was in the electrical engineering curriculum at college at the time prior to switching to computer science), I've never stopped looking at things from the perspective of an engineer and have always enjoyed physics (which is at the foundation of all this). It's one of the reasons I'm actually quite excited to get back into the process of suspension modification (though the real reason is, of course, the fun I expect to have on the track!). There's nothing quite as edifying as analyzing a problem, seeing a potential solution, trying that solution, and seeing it work.

Thank you very much KCBrown. That is the nicest thing anybody has said to me on this thread. I am not as ignorant as people are trying to portray me. I am in fact just short of an expert in car accident reconstruction and have taken several classes on it. I understand basic equations and if there is something that somebody brings up and that i don't understand, I look it up and try to educate myself until I grasp it.

What has happened on this thread is quite simple. I gave too glowing a report on an aftermarket part. Jaded forumites became irritated because in their experience there is no magic. I understand somewhat, because I tend to agree with that point of view. Because I am not Road and Track and didn't have before and after skidpad, quarter mile and track results, it was easy for everyone to say I was and am full of shit. Others took it a step further and attacked my politics.

I have made it worse by not backing down. Normally, I would if there was any doubt in my mind. But there isn't. I am somewhat bolstered in this me against the world stance by the fact that it really isn't me against the world and that people in the know who do not participate here have my back. And just as there are ones here who laugh at me. There are many with me who just shake their heads at them. They are not engineers either, but enthusiasts who were kind enough to share their experience with me and turned me on to a great aftermarket part that cures a lot of what is wrong with the rear suspensions of the most recent iteration of the S197.

Thank you for your kind words and my mind is open despite what you read.

 

[barbaro]

So exactly how much time do YOU have on a racetrack or autocross course (and don't lie). And street driving doesn't amount to squat. Nor does listening to vendors peddle their own products.

But I have to agree on your one point, arguing with you is a waste of time and they (me included) should know better

A little over 100 laps at Willow Springs Big Willow. Half of thos laps was with the torque Arm, half were not. you don't have to tell me not to lie. As for street driving not amounting to squat. I have driven my car on virtually abandoned mountain roads almost as hard as the track. Google map soledad canyon, sand canyon, little tujunga canyon, mulholland drive. It is an advantage of my location. So don't argue with me then Viking unless you have specific knowledge of the parts I am talking about. Then when you come from a place of knowledge we can have an intelligent discussion, rather than an argument.

 

[Whiskey11]

Barbaro, you know of me, you know that I have a Cortex Torque Arm, my body roll has not changed at all... squat and dive, sure, maybe a little but it's barely noticeable. Those effects can be explained, reduced body roll is NOT something a Torque Arm does, if anything you will see a slight increase in it from removing the roll resistance from bushing bind but I'll be damned if you or anyone else can tell the difference between the body roll of a car with the stock, or aftermarket UCA and one with a torque arm. You are fooling yourself and other readers if you think that is true.

 

[barbaro]

Barbaro, you know of me, you know that I have a Cortex Torque Arm, my body roll has not changed at all... squat and dive, sure, maybe a little but it's barely noticeable. Those effects can be explained, reduced body roll is NOT something a Torque Arm does, if anything you will see a slight increase in it from removing the roll resistance from bushing bind but I'll be damned if you or anyone else can tell the difference between the body roll of a car with the stock, or aftermarket UCA and one with a torque arm. You are fooling yourself and other readers if you think that is true.

More accurately . . . my car corners flatter. And I explained why that is. The torque arm is not a sway bar and I am not implying that it is. Also recognize that my setup is quite a bit different than yours. You have higher spring rates and firmer dampening.

But I will repeat my subjective experience. Previously, in a high speed corner, braking made my nose dive and my rear end lift. (I recognize stiffer springs and coilovers such as you have could solve this also) As I turn in, my car is articulated with the nose in the ground and the ass in the air. Consequently, I lose rear end grip and my car is not level at turn in. Now turn in adds centrifugal force to a car that is articulated poorly due to nosedive. The subjective experience is excessive chassis movement up, down and sideways. If I trailbrake this position is exaggerated through turn in. My unloaded rear end leads to oversteer that is squirrely rather than controllable. If I am using trailbraking to set my rear end for track out after the apex things don't go so well

With the torque arm, I brake, no excessive nosedive or unloaded rear end. At turn in my car is flatter whether I am applying the brake or not. The centrifugal force at turn in does not seem as severe. My rear end bites after apex and during track out. The subjective feeling is of a chassis that does not lean quite as much as it did before. As a result my confidence is multiplied and I drive faster.

 

[kcbrown]

Barbaro, you know of me, you know that I have a Cortex Torque Arm, my body roll has not changed at all... squat and dive, sure, maybe a little but it's barely noticeable. Those effects can be explained, reduced body roll is NOT something a Torque Arm does, if anything you will see a slight increase in it from removing the roll resistance from bushing bind but I'll be damned if you or anyone else can tell the difference between the body roll of a car with the stock, or aftermarket UCA and one with a torque arm. You are fooling yourself and other readers if you think that is true.

I was under the impression that he was, in the end, talking about roll of the car in turns while under braking or acceleration. I can easily see how a device that changes the squat/dive characteristics of the car would have an impact on that.

Also, what you feel in the car can be quite a bit different than what's actually going on physically.


One of the reasons engineering can be a difficult discipline is that an engineer has to work with specifics, because the specifics of what he is attempting to achieve will have a huge impact on the methods he selects for achieving them. When a customer has a set of requirements, they can often be relatively vague, and that is frustrating to an engineer precisely because the engineer knows that the vagueness will result in either a solution that is displeasing to the customer or an inability to arrive at a solution at all.

Professional race car drivers have teams of people who know how to work with them. Those people can ask questions of the driver and translate their responses into something that is understandable from an engineering perspective. When there is ambiguity, the engineers will ask the driver questions that will yield clarification. Because the team is committed to winning, the driver will obviously find it in his best interests to learn as much of the engineering language as he can so that he can communicate his observations more precisely. It's a back and forth experience that improves the team. What's happening here is similar to that, but with one crucial difference: nobody is asking the driver the clarifying questions that will remove ambiguity. That's not a slight on anyone here, since we're not attempting to perform as a racing team or something. But it does appear to be a valid observation about what's going on.

 

[barbaro]

Also my friends and I will be renting Big Willow again in October. It is a closed group, however I invite anybody on this forum to the track as my guest. It will be cheap. How cheap depends on a few things. Sometimes we have as few as 6 or 7 people and it is great. I have had the track all to myself on several occasions. I also will be participating in the Mojave Magnum that same month but that you have to sign up for yourself.

 

[kcbrown]

Barbaro, you know of me, you know that I have a Cortex Torque Arm, my body roll has not changed at all... squat and dive, sure, maybe a little but it's barely noticeable.

Right, but you're running springs that are what, about twice the rate as his? More? I would expect that to dominate the equation, to make up for most of the difference.

Even so, your LCA setup isn't ideal thanks to the rules you're running under, so it's possible that you'd be able to get a lot closer to what the TA gets you if you could relocate your LCAs.

 

[sheizasosay]

Also my friends and I will be renting Big Willow again in October. It is a closed group, however I invite anybody on this forum to the track as my guest. It will be cheap. How cheap depends on a few things. Sometimes we have as few as 6 or 7 people and it is great. I have had the track all to myself on several occasions. I also will be participating in the Mojave Magnum that same month but that you have to sign up for yourself.

You have any gopro's? If possible, capture the TA and one LCA/wheel. If you have another cam, put that one on the side of your car at the back. I know it sucks getting under the car when it's lowered. Last time I did it to (for this thread actually) it was to watch the UCA. Unfortunately the lighting was piss poor and was worthless.

 

[dontlifttoshift]

First I started this thread. Second I have driven and tracked the very part this thread is about. Third, the thread is getting technical again? Hypothetical talk about the possibility of NVH in a Torque arm with little reference to experience with the unit is edifying to you? This is why I don't get some of you. In the Cortex Unit, it is a non-issue or at the very least such a minor issue as to not merit this much analysis by people who have never used it. This should not be called Corner Carvers but "Hypothetical Problems and Issues in Parts we don't have and Will probably not use forum." Sounds like the title of a bad college class.

You and yours parse everything I say on the lookout for hyperbole exaggeration, understatement, the slightest inaccuracy, or incorrect verbiage in order to imply the most negative connotation. Always coming down to the ultimate conclusion which is you don't know what you are talking about, you are an idiot, STFU etc . . . What I said does not discredit me or anyone else.

That is your hyperbole, exaggeration and overstatement. Wouldn't it be nice if you had just a smidgen of experience with the equipment? Wouldn't it be nice if you had actually driven the car before and after? Or any similarly equipped car before and after. Wouldn't it be nice if you had driven such a car at the track( I have), On a mountain road (I have), on the street. (I have) That way you could opine with credibility about NVH, handling characteristics, pitch and yaw and bodyroll, antisquat, quadratic equations, E=MC squared etc . . . but you don't have that. What you do have is a small mob that largely has the same experience as you, none.

I had to quote the whole damn post so you don't think I took it out of context. When you say that, I'm going to paraphrase here, "I recommend this part over tires and shocks" that is wrong. Parts will never be more important than tires. That is MISINFORMATION that does not need to be spread on this forum. That is what discredits your statements. I never said you discredit anyone elses statements, just your own.

I found this in your first post of this magical thread.

First let me qualify my words with the fact that I am an Amateur driver with a capital A. Thus, nothing I say is definitive on anything except I guarantee you it is honest.

The disclaimer reads that nothing you say is definitive, however, any words that contradict yours are wrong. I have not argued for or against a torque arm, my issue is with your presentation and continuous support of misinformation even after you have been shown the technical side of things.

 

[Whiskey11]

Right, but you're running springs that are what, about twice the rate as his? More? I would expect that to dominate the equation, to make up for most of the difference.

Even so, your LCA setup isn't ideal thanks to the rules you're running under, so it's possible that you'd be able to get a lot closer to what the TA gets you if you could relocate your LCAs.

You seem to be implying that because I don't have relocation brackets that I wont experience the true benefit of the torque arm suspension and that my higher spring rates are the reason I'm not seeing the full benefits?

First and foremost, my spring rates are probably over double his at 440 front and 200 rear (the rears will be the closest to each other). I'm thinking about adding more, because, you know, springs control body motion not a torque arm, and because the car needs it desperately. Here is my car at the Nebraskhana event with the OEM 3 link, but otherwise unchanged suspension from now:

Here is my car at the MidDiv Championship with the Torque Arm:

And my car last weekend still with the Torque Arm:

Virtually unchanged. The last photo is even under braking. I'm getting that roll angle with 440 lbs/in springs. Cars with stock springs or Boss 302 springs will be worse and less than ideal. Why anyone would chose those rates is beyond me and "ride quality" is a load of bull. I would gladly put my Ground Control coilovers against the stock Boss 302 suspension in a subjective ride quality test. The roads here in Nebraska are far, far, far worse than anything Barbaro sees in California and I think my car rides better than it did stock.

As for the control arm angles, do you honestly think that if I could change the angles of the control arms I would have gone with the Torque Arm setup in the first place? Nope, I wouldn't have and I wouldn't have because I honestly don't think it adds much if anything over a properly set up 3 link. Sure, Filip and Bruce both have their reasons behind choosing the TA setup which includes "not being able to setup a 3 link with as much %AS without getting into roll steer issues" and I think that is noble, but I have yet to see a conclusive A-B test where the only change is the torque arm that shows the TA is either faster or easier to drive. I went with the TA because it had a quantifiable impact on forward bite in the broken SCCA rules.

 

[barbaro]

I had to quote the whole damn post so you don't think I took it out of context. When you say that, I'm going to paraphrase here, "I recommend this part over tires and shocks" that is wrong. Parts will never be more important than tires. That is MISINFORMATION that does not need to be spread on this forum. That is what discredits your statements. I never said you discredit anyone elses statements, just your own.

I found this in your first post of this magical thread.



The disclaimer reads that nothing you say is definitive, however, any words that contradict yours are wrong. I have not argued for or against a torque arm, my issue is with your presentation and continuous support of misinformation even after you have been shown the technical side of things.

Stop with the "technical side of things" bullshit please. You are adopting Norm's line that I am some technical dunce which is bullshit propaganda. I probably know more physics and math than most people who read this forum. On top of that, the proof is in the pudding. I build some real nice street cars that are trackable. Show me a nicer ""street" car (2011-2014 Mustang GT) than mine, I would like to see it. That did not happen by accident. I did not give my car to Shelby or Saleen and say take care of it. I did things that nobody else was doing before anybody else was doing it and it was all me. Conception, design and execution. And it worked. you don't have to give me respect, but the disrespect is uncalled for.

Second, A guy with a stock Brembo package has a pretty good handling car for stock. The car rides nice with the shocks it has. The Pirelli's are not as bad as people let on, If I had the choice between new tires and shocks and the Cortex rear grip package n a stock car, I reiterate I would go with the Cortex rear grip package. I would have a much better handling car and maintain better than stock driveability.

My opinion is for the consumption of someone who wants a better handling street car not a race car. There is no objective truth. If you have a different opinion that is fine. it does not make my opinion bullshit.

 

[TheViking]

A little over 100 laps at Willow Springs Big Willow. Half of thos laps was with the torque Arm, half were not. you don't have to tell me not to lie. As for street driving not amounting to squat. I have driven my car on virtually abandoned mountain roads almost as hard as the track. Google map soledad canyon, sand canyon, little tujunga canyon, mulholland drive. It is an advantage of my location. So don't argue with me then Viking unless you have specific knowledge of the parts I am talking about. Then when you come from a place of knowledge we can have an intelligent discussion, rather than an argument.

Here goes, my shot at having an intelligent discussion with you.

You're lifetime track experience consists of approximately 100 laps on a single course. By your own admission lap times are probably in the 1.40 range. So we can estimate your collective track time at approximately 2 - 2 1/2 hours total or the equivalent of ONE typical track day/HPDE event. Yet you are attempting to establish yourself as an authority on this topic (torque arms). Neither your track/competition experience or chosen profession bear this out. You are certainly an authority on how this setup on your car makes you feel. But this does not qualify you in any way to make the sort of bold, overreaching statements you have provided throughout this discussion.

I stand by my statement that street time doesn't count for squat. I have never met a newbie who didn't learn more about high performance driving/car control/etc at a single track event then they did over there collective street 'experience'. You simply cannot compare the two environments as equals in regards to a learning tool.

 

[dontlifttoshift]

I probably know more physics and math than most people who read this forum. On top of that, the proof is in the pudding. I build some real nice street cars that are trackable. Show me a nicer ""street" car (2011-2014 Mustang GT) than mine, I would like to see it. That did not happen by accident. I did not give my car to Shelby or Saleen and say take care of it. I did things that nobody else was doing before anybody else was doing it and it was all me. Conception, design and execution. And it worked. you don't have to give me respect, but the disrespect is uncalled for.

Hilarious! I will try not to say anything technical as you do not care to discuss it.

You disrespect 99% of the forum. You call bullshit when many people call you on your bullshit and then assume the title of pioneer when it comes S197 modifcations with all of your bolt on parts. In addition to that, it sounds like you drive like a tool on the street. I hope someones family isn't in a minivan around the bend when you run out of talent and cross the centerline. Yes sir, the disrespect has been earned.

Conception, design, and execution??!! When you start with bare frame rails on a chassis table and build a car around it, let me know and we can discuss those 3 things.

 

[Norm Peterson]

Do we know if the Torque Arm in question is hollow or solid?

Per http://www.cortexracing.com/shop/xtreme-grip-torque-arm-system/ it appears to be a built-up beam with tubes for top and bottom flanges and a "normal" piece of sheet or strip steel in between them serving as the beam's web. Given the likely height restrictions, it's a good approach from a structural point of view to get stiffness without requiring flange width that would likely interfere with exhaust or the use of unreasonably thick solid flanges.

It would seem that if the arm was hollow and if one had access to the hollow cavity within the arm there may be options to squash much of the NVH transmitted thru the arm by filling the void with a "dead" material/matter if someone was bothered by it. Granted, this certainly wouldn't help those who care about weight but it seems like a reasonable approach.

Filling the tubes might be a good way to go if the basic design proves to be sensitive to other differences in the rear axle and its linkage and drive shaft. After all, that was Ford's own approach on the PHB, which is a tube of similar diameter and length to the tubes in this TA. Obviously the option to fill or allow to be filled is best provided during the TA design stage, as you don't want to risk generating a location of high/intensified local stress and fatigue issues by drilling hole(s) at any old location or not reinforcing around them no matter where you might put them. Lead shot or maybe just sand ought to work as filler - you don't want something that will develop much of a 'ping' of its own.

Aftermarket upper control arms for S197's are notorious for clunking and transferring NVH into the chassis. I have personally experienced this as have others who have written about it.

The clunking (and the squeaking that's partly related) is a well-known problem with aftermarket poly-bushed control arms in general, even lowers. The clunking is related to (1) bolt to hole clearance and (2) the poly material as supplied being longer than the inner sleeves that the bolts run through. I've posted my "fix" for this many times on multiple forums. At least one vendor has addressed the bolt to hole clearance issue.

Honestly - I'd have been surprised if you didn't note the clunking, and I'd have noted it as well if I was the sort who simply pulls the new parts out of the box, assumes that they are fully developed in all respects, and bolts them onto the car. That's likely one more of the differences between you and me, and the problems with standard poly bushings really is that obvious once you better understand what's going on in a suspension pivot. I've nearly always modified poly bushings and never had to put up with or solve any clunking issues. The only consistent squeaks came from the bushings that didn't feature sleeves and which weren't physically possible to modify.

Noise transmission will go up as soon as you swap rubber out for poly. This is that "mechanical impedance" thing I noted earlier, and the greater the difference you can achieve in this property between the metal arms and their non-metallic bushings the better your vibration isolation will be. If this wasn't true, the OE's would use stiffer materials for their bushings (some of the GT500 bushings are claimed to be something like 28% stiffer than standard S197 bushings, so this is certainly something they've looked at).

I suspect that you may be coming into this from cars that were relatively quieter than most of mine were. A minor increase in NVH transmitted into the cabin has never bothered me (some of my 1970's-era work involved a daily-driven Pinto with 500 lb/in front springs, a 7500 rpm engine, and noisy tires).

That is why I am not a fan of aftermarket Upper Control Arms.

That's an easy enough position to understand if you're relatively more sensitive to NVH and not aware that there are a few things you can do about it. But I hope you can see that the details of aftermarket control arm bushing are a separate detail issue not really related to the 3-link as a general suspension linkage arrangement.

Two and only two people that I have encountered, and they are both on this forum have noticed a slight gear whine as a result of the Torque Arm. Some have complained about Griggs Torque Arms transferring NVH but it is a very minimal in the Cortex unit. The Griggs has different design. I do know that Filip changed the bushing over a year ago to ameliorate this very problem.

That Filip is continuing to evolve his design based on early user feedback is a good thing.

First I started this thread.

Understood. But as soon as it appears in the public domain for comment you lose the ability to fully control the direction(s) it might ultimately take. Some tangents will be technical and technically relevant, others not, and some (including some of yours) not on the original topic at all.

Second I have driven and tracked the very part this thread is about. Third, the thread is getting technical again? Hypothetical talk about the possibility of NVH in a Torque arm with little reference to experience with the unit is edifying to you?

It is not 'hypothetical' to discuss physical properties that apply to every part of a the car, and certainly to all of its structural components. Don't dismiss this out of hand simply because the technical content involved is foreign to you.

This is why I don't get some of you. In the Cortex Unit, it is a non-issue or at the very least such a minor issue as to not merit this much analysis by people who have never used it. This should not be called Corner Carvers but "Hypothetical Problems and Issues in Parts we don't have and Will probably not use forum." Sounds like the title of a bad college class.

When you've been involved with structural vibration in your day job in one way or another for nearly 40 years it drops out of the theoretical domain of the college classroom and falls to an everyday conversation level. I have tried to get it across before that once you have a grasp of the technical basics it is an easy next step to apply that knowledge to systems that you haven't directly experienced or even systems that haven't been built yet.

You and yours parse everything I say on the lookout for hyperbole exaggeration, understatement, the slightest inaccuracy, or incorrect verbiage in order to imply the most negative connotation. Always coming down to the ultimate conclusion which is you don't know what you are talking about, you are an idiot, STFU etc . . . What I said does not discredit me or anyone else.

What can I say? Engineers need technical precision even in descriptions of observed behavior, otherwise any analysis would be flawed because the information to start from was poorly described/defined. I'm not the only one who has mentioned this. For the most part, technical content is posted flat, or devoid of intended emotion.

It becomes necessary to parse things people write in order to break the total up into manageable bites and provide an answer to each part. A stream-of-consciousness writing style is for book writers, and I've picked on more than one engineering report in my day jobs for being written with too many thoughts per paragraph.

That is your hyperbole, exaggeration and overstatement. Wouldn't it be nice if you had just a smidgen of experience with the equipment? Wouldn't it be nice if you had actually driven the car before and after? Or any similarly equipped car before and after. Wouldn't it be nice if you had driven such a car at the track( I have), On a mountain road (I have), on the street. (I have) That way you could opine with credibility about NVH, handling characteristics, pitch and yaw and bodyroll, antisquat, quadratic equations, E=MC squared etc . . . but you don't have that. What you do have is a small mob that largely has the same experience as you, none.

You're in no position to judge my credibility. Recent 6-figure money for work dealing with structural vibrations and a couple of unique noise and vibration designs of mine that appear on an entire class of submarines suggests that enough people think otherwise to make your opinion that of a small and poorly informed minority. I can live with that.

More accurately . . . my car corners flatter. And I explained why that is.

And this is exactly what I'm trying to get you to understand is misleading. "Flatter" while cornering normally applies to roll rather than pitch. You have to fit yourself and your descriptions to that convention, because it isn't going to change just to suit you. Learning only that one thing would have made this thread a whole lot shorter and far less confrontational.

The torque arm is not a sway bar and I am not implying that it is.

You may not have meant to imply that, but that is exactly the way your other descriptions have read.

But I will repeat my subjective experience. Previously, in a high speed corner, braking made my nose dive and my rear end lift. (I recognize stiffer springs and coilovers such as you have could solve this also) As I turn in, my car is articulated with the nose in the ground and the ass in the air.

Hard braking does that. You aren't the only one who gets into "nose dive" under hard braking. I guess it bothers some folks more than others, though. I didn't find this particularly upsetting, as the car got to that nose-down/tail-up attitude pretty quickly without overshooting and bobbling a time or two before settling on that position

Consequently, I lose rear end grip and my car is not level at turn in. Now turn in adds centrifugal force to a car that is articulated poorly due to nosedive. The subjective experience is excessive chassis movement up, down and sideways. If I trailbrake this position is exaggerated through turn in. My unloaded rear end leads to oversteer that is squirrely rather than controllable. If I am using trailbraking to set my rear end for track out after the apex things don't go so well

Have to think on this a bit to see if I can picture it. 3-D visualization and visualization over time is involved.

With the torque arm, I brake, no excessive nosedive or unloaded rear end.

OK.

At turn in my car is flatter whether I am applying the brake or not.

Immediately after getting off the brakes, this will be true, but the car will correct itself to essentially the same pitch angle within a small fraction of a second.

The centrifugal force at turn in does not seem as severe.

Could this be based on simply observing less "dive" at the outside front corner? As mentioned by others, perception sometimes feels like reality even when it's not.

My rear end bites after apex and during track out.

Expected.

The subjective feeling is of a chassis that does not lean quite as much as it did before. As a result my confidence is multiplied and I drive faster.

Improved confidence does allow you to go faster. Although the amounts of chassis movements are part of this, I'm pretty sure that more than just the absolute amounts of roll and pitch is involved.

Also, what you feel in the car can be quite a bit different than what's actually going on physically.

This ↑↑↑, precisely. Even this ↓↓↓ doesn't feel nearly as bad to drive as it looks.

One of the reasons engineering can be a difficult discipline is that an engineer has to work with specifics, because the specifics of what he is attempting to achieve will have a huge impact on the methods he selects for achieving them. When a customer has a set of requirements, they can often be relatively vague, and that is frustrating to an engineer precisely because the engineer knows that the vagueness will result in either a solution that is displeasing to the customer or an inability to arrive at a solution at all.

Professional race car drivers have teams of people who know how to work with them. Those people can ask questions of the driver and translate their responses into something that is understandable from an engineering perspective. When there is ambiguity, the engineers will ask the driver questions that will yield clarification. Because the team is committed to winning, the driver will obviously find it in his best interests to learn as much of the engineering language as he can so that he can communicate his observations more precisely. It's a back and forth experience that improves the team. What's happening here is similar to that, but with one crucial difference: nobody is asking the driver the clarifying questions that will remove ambiguity. That's not a slight on anyone here, since we're not attempting to perform as a racing team or something. But it does appear to be a valid observation about what's going on.

Very good explanation. I think a few vague hints for clarifications have been made, but probably too subtly.

Rest assured Norm, I have not forgotten you.

You have gone to great pains to parse all my statements. Rhetorically, that is wise because it allows you evaluate statements out of context for your purposes. You examine the tree and miss the forest.

This fuss about body roll. My car corners flatter since the installation of the torque arm. Everyone I know who has one says the same thing. Now whether that is mainly attributable to less pitch or yaw or roll I could not tell you subjectively. But you can tell me and I don't dispute you. But the effect is the car is flatter going in and coming out of turns. I leave it to you to define it further. I think I have explained myself several times on this issue.

At least you're getting better at describing it.

The problem with "Everyone I know who has one says the same thing" is that the members of that "everyone I know" group tend to be random individuals, most of which are not very good at separating effects and frequently get cause and effect mixed up. I see this a lot. Undoubtedly you've heard drag racers and street racers state that rear suspension squat causes rearward "weight transfer" - well, they've got it exactly backwards. The situation here sounds very similar.

My math background ended at high school calculus in which I got an A As I remember it. I had one year of physics at UCLA and I got a B both semesters. I took high school Shop and I can accomplish most repairs on my car if I have to. I don't work as much on my car anymore because people pay me a lot of money for my time and advice and it is not cost effective for me to do it. I went to reputable universities. I got good grades. That being said, I half understand you. I acknowledge the importance of thinking things out from an engineering perspective. It is essential. I do appreciate your knowledge. I have been edified by several of your posts on other forums.

Thanks. Really.

But for many here including you, this thread has become personal. And you are using your background not to fairly reflect on the subject at hand but to slam me by parsing out any hint of unorthodoxy, innacuracy, over or understatement, with the full knowledge that you have the support of some other ossified 1000 plus posters on this forum.

I wish you didn't feel 'slammed'. That's not my intent. I'd rather teach you something that I have some familiarity with that's apparently fairly new to you. There's a good chance I'd be benefitting more as well if there wasn't quite as much noise.

What is irritating you and others is that I won't back down. I persist in my opinion despite the "math" and the opinions of several others who have not used the parts I am posting about. I do this only when I know what I am talking about. When it comes to what these parts do, what their practical effect is, I know what I am talking about.

Try to keep your observations independent of what you think the parts are supposed to be doing and everyone will be better off. What if they did something unexpected that you didn't like even if you were led to expect all good and no bad?

You and others are arguing with my subjective experience.

Not the experience per se, but the description of it. Accuracy in describing observations is an essential skill for a test driver to possess, and when you or I or anybody else tries to describe what their car is doing we're specifically becoming our own "test driver".

It is ludicrous. et seq

Fail. Find another analogy.


Norm

 

[barbaro]

To Whiskey 11. I don't have any experience with roads in Nebraska but It is hard to believe they could be worse than Los Angeles.
I have Heim jointed Adjustable Control arms with relocation bracket. You do not apparently.
My rear spring rate is 181 My front is 167 lbs. I believe.
I have a Cortex Watts Link you have a Fays II
I have a Torsen T2R differential you do not
We have very different setups. The principle differences being spring rate and lower control arms with relocation brackets. Your front spring rate is over double mine. So when i put a torque arm on my vehicle which is integrated by design with my other parts can you entertain the possibility that it may work really well? You said that you can now launch your vehicle at 3500 rpm as opposed to 2000 before. Would that not in and of itself give you a few tenths from a standing start?

I have tried various upper control arms and they suck. Not saying there is not a good one out there, but I have not experienced it and neither has Terry Fair. So tell me what UCA is superior to a torque arm? And the ride quality issue is paramount. An aftermarket upper control arm will degrade ride quality even if it improves handling. A torque arm improves ride quality and handling and bite.

Your autocross rules force you to live in an artificial universe that i don't have to live in.
As for coilovers and ride quality, it might be good, but I know the Boss set-up is good. Would I like more Spring rate for the track . . .of course, it seems like you can never have too much. My car only sees the track 4-5 times a year. I have tried spring rates as high as 250lbs in the front. Ride was horrible and it denigrated handling on the street. I am contemplating the street Cortex Coilovers and as soon as I get 3 grand together I will give it a go as Filip assures me the ride quality will be acceptable and I do trust the guy.

 

[barbaro]

Here goes, my shot at having an intelligent discussion with you.

You're lifetime track experience consists of approximately 100 laps on a single course. By your own admission lap times are probably in the 1.40 range. So we can estimate your collective track time at approximately 2 - 2 1/2 hours total or the equivalent of ONE typical track day/HPDE event. Yet you are attempting to establish yourself as an authority on this topic (torque arms). Neither your track/competition experience or chosen profession bear this out. You are certainly an authority on how this setup on your car makes you feel. But this does not qualify you in any way to make the sort of bold, overreaching statements you have provided throughout this discussion.

I stand by my statement that street time doesn't count for squat. I have never met a newbie who didn't learn more about high performance driving/car control/etc at a single track event then they did over there collective street 'experience'. You simply cannot compare the two environments as equals in regards to a learning tool.

And your complete lack of experience with my set up qualifies you to be the definitive authority on what exactly . . . .? I am not an authority on anything and neither are you. I simply shared my experience fortified by the experience of several others. And over 50 laps of track time and 8-9000 miles on the street is I believe sufficient to evaluate the parts I am talking about. Additionally, it is over 1000% more experience than you have evaluating these parts. So ho how do you propose you are qualified to substitute your judgment for mine on a parts you have no familiarity with on a car you have never driven? That is chutzpah. Not knowledge.

Because I know one thing beyond a doubt and that is if you drove my car before and after like I did. You wouldn't be talking the smack you are talking now. I have the undeniable advantage of experience with what I am talking about.

 

[barbaro]

Hilarious! I will try not to say anything technical as you do not care to discuss it.

You disrespect 99% of the forum. You call bullshit when many people call you on your bullshit and then assume the title of pioneer when it comes S197 modifcations with all of your bolt on parts. In addition to that, it sounds like you drive like a tool on the street. I hope someones family isn't in a minivan around the bend when you run out of talent and cross the centerline. Yes sir, the disrespect has been earned.

Conception, design, and execution??!! When you start with bare frame rails on a chassis table and build a car around it, let me know and we can discuss those 3 things.

Rebuilding my engine and porting my heads back in 2010 when nobody was doing it was just bolt on huh? Find a streetable naturally aspirated 5.0 that turns out 522 horses on 91 octane. Look real hard. You call me a tool and then you say I disrespect 99% of the forum. I don't disrespect 99% of the forum. A select few here disrespect me and you are one of them. I have never said anything to anybody on this forum that I would not say to their face. Call me a tool to my face and see what happens. I guarantee you, you do not have the courage. And if you do have the courage you will pay a price for it. Be respectful. It is a forum rule after all. So I am not going to call you any names.

As for starting with bare frame rails. I have done that too and am contemplating doing it again. I am accumulating parts to do just that.