Torque Arm. Here is why.

[MechE]

Great discussion gents. Thank you.

 

[SoundGuyDave]

Filip,

Welcome, and thank you for bringing the tech to light on this subject. Both pros and cons...

Hope you stick around; a number of us would value your insights.

 

[kcbrown]

Filip,

Welcome, and thank you for bringing the tech to light on this subject. Both pros and cons...

Hope you stick around; a number of us would value your insights.

I'll second that!

I think it's interesting that the problems with the 3-link's SVIC come into play when the car is lowered to race height. But that raises the question: why lower the rear in that manner? We're talking about racing, in which appearance is irrelevant. So what if the rear makes the car look like a 4x4? If the geometry is good back there, who cares?

If you lower the rear by, say, 1.5 to 2 inches, what are you really gaining, assuming that your geometry and spring rates were optimal prior to the drop? Sure, you lower the CG slightly, but (from what I've seen) you also move the rear suspension's roll center by about the same amount, so the roll arm's length remains the same.

Running softer springs (which, as Filip notes, is desirable, but obviously that doesn't imply that the stock rates are anywhere close to optimal!) necessarily means you have to have more available travel, but that means less lowering than you might otherwise perform. I expect you'd want to keep the suspension off the bump stops because the bump stops represent a rapid and large increase in the stiffness, and dampers generally don't have position-dependent valving -- which means the dampers will be asked to damp what amounts to a much higher spring rate for however long the suspension remains in the bump stops. This is a similar problem to running progressive springs, only much worse.


All of which is to say that this looks like a big, messy compromise, and I'm having some trouble understanding why it seems there is such a strong desire to lower the cars substantially (particularly up front, where lowering the car increases the roll arm at twice the rate the car is lowered. And note that "substantially" here means "enough to noticeably affect the geometry"). That is something I'd very much like to hear Filip talk about.

 

[barbaro]

You'd never call it hyperbole if you had seat time in certain years of the 4th gen F-body.

Keep in mind that the parts and the suspension configuration don't know what emblem the car wears and doesn't care. You should care about the F-body characteristics, because with slight differences in detail or maybe just bushing/rod end wear maybe it could be your car with the dancing stick axle in the braking zone. Not all 3-link cars hop under acceleration, either. The devil is in the details, not the badge on the car.

FWIW, I've driven F-body cars in autocross competition, and they're easy cars to drive hard as long as you stay out of brake hop.
Translation - I'm not anti-torque arm. And FWIW I've probably watched all of Filip's videos at least once.

It's easy enough to find examples of F-body brake hop in case you'd rather not take anybody's word for it. The interesting part starts about 30 seconds in. Me, I'd prefer that the fillings stayed in my teeth

http://www.bing.com/videos/search?q...27CBF27FCE8BB36C53FB27CBF27FCE8BB36&FORM=VIRE


Norm

Norm, of all your arguments this is the most disingenuous one. You are an engineer and you know if brake hop is going to be an issue at all it's completely dependent upon the geometry of the vehicle and the torque arm relative to it.

What Filip said.

I, too, have watched the video, and understand the terms involved. He describes why a torque arm is useful (yields good anti-squat when the lower control arms are configured properly). But importantly, he doesn't explain how it is superior to the upper control arm the Mustangs come with. He doesn't even hint at how it is superior in that respect. He shows how you can get certain amounts of anti-squat with different lower control arm angles in conjunction with the torque arm. He doesn't claim that you can't do the same thing in the same way with an upper control arm setup.


Now, that doesn't mean that the torque arm he designed isn't better in at least some ways for at least some things (it could well be, and he appears to be enough of an engineer that I find it unlikely that he'd settle on that solution without good engineering reasons). It only means the video doesn't explain how it might be better, and that means the video you referred us to doesn't tell us what you claim it does (which is to say, it doesn't tell us why you'd want a torque arm instead of the upper control arm).

Watch the video again. He Explains why the torque arm more effectively transfers torque to the tire rather than dissipating it through the chassis

 

[kcbrown]

Watch the video again. He Explains why the torque arm more effectively transfers torque to the tire rather than dissipating it through the chassis

He explains how it effectively does that. He doesn't explain how it more effectively does that.

That's an important distinction. The video does not perform any comparisons. Filip talks about the torque arm, and only the torque arm, as the means of constraining the rear axle in rotation. The rest of the discussion centers around the lower control arms, which are the same in both cases.

 

[barbaro]

Did you read his response on this forum? If that doesn't settle it, I don't know what to tell you.

 

[ford20]

I'll second that!

I think it's interesting that the problems with the 3-link's SVIC come into play when the car is lowered to race height. But that raises the question: why lower the rear in that manner? We're talking about racing, in which appearance is irrelevant. So what if the rear makes the car look like a 4x4? If the geometry is good back there, who cares?

If you lower the rear by, say, 1.5 to 2 inches, what are you really gaining, assuming that your geometry and spring rates were optimal prior to the drop? Sure, you lower the CG slightly, but (from what I've seen) you also move the rear suspension's roll center by about the same amount, so the roll arm's length remains the same.

Running softer springs (which, as Filip notes, is desirable, but obviously that doesn't imply that the stock rates are anywhere close to optimal!) necessarily means you have to have more available travel, but that means less lowering than you might otherwise perform. I expect you'd want to keep the suspension off the bump stops because the bump stops represent a rapid and large increase in the stiffness, and dampers generally don't have position-dependent valving -- which means the dampers will be asked to damp what amounts to a much higher spring rate for however long the suspension remains in the bump stops. This is a similar problem to running progressive springs, only much worse.


All of which is to say that this looks like a big, messy compromise, and I'm having some trouble understanding why it seems there is such a strong desire to lower the cars substantially (particularly up front, where lowering the car increases the roll arm at twice the rate the car is lowered. And note that "substantially" here means "enough to noticeably affect the geometry"). That is something I'd very much like to hear Filip talk about.

I'm going to guess that when you are talking about race height you are also look at aerodynamics as well since that is one of the greatest competitive edges you can possibly have.

 

[barbaro]

Filip,

Welcome, and thank you for bringing the tech to light on this subject. Both pros and cons...

Hope you stick around; a number of us would value your insights.

Sounds Guy Dave, thank you for thanking Filip. 1) Are you prepared to moderate your views with respect to torque arms on the s197 chassis? 2) are you prepared to stop mocking me for advocating it? 3) Are you prepared to thank me for bringing this issue to the fore so that you could have the opportunity to have direct discussion with Filip himself?. ;-)

Filip,

Welcome, and thank you for bringing the tech to light on this subject. Both pros and cons...

Hope you stick around; a number of us would value your insights.

Lets be honest, overwhelmingly Pros, very little Con

 

[kcbrown]

If maintaining stock ride height is desirable to you then the torque arm is your friend. With a torque arm you don't need low stiff Springs to keep your car level.

But Filip himself just now said that the torque arm gives you the least amount of advantage with a car that has a stock ride height, relative to one that is lowered.

That's not to say that the TA won't bring any advantages to a stock ride height car. On that, I cannot say. I'd like Filip to chime in on what those advantages would be if you keep the rear suspension the same as stock as far as geometry goes.

As for suspension geometry that can be corrected. I use the Maximum Motorsports K member which allows me two mounting holes for my lower control arm to correct for changes in suspension geometry. Also lowering the car up front is absolutely necessary for her aerodynamics. This car's high drag coefficient, needs to be ameliorated somehow.

Sure. I'm not arguing that there are no advantages to be had by lowering the car. But if you're really going balls to the wall, then you'll rip out the entire front suspension and replace it with a SLA suspension, just to get rid of the camber related compromises that come with a McPherson strut suspension. Done right, you'll even be able to locate the roll center exactly where you want it.

But here, we're talking about the rear suspension, and why you'd want to lower it. I suppose there might be some additional drag reduction in lowering the rear, but oddly enough, the first thing that'll be done after that is to add aero to the rear of the car which increases drag. I've no idea how much rear downforce you'd lose by lowering the rear of the car by a couple of inches. Having the front lower than the rear means the floor of the car is canted slightly, which will yield a low pressure area under the car, which in itself causes downforce. You'd lose some of that effect by lowering the rear.


To be clear, I'm not disputing that there are advantages to lowering the car in the rear. I'm asking what those advantages are, especially in light of the geometry compromises that inevitably result.

 

[barbaro]

Where is the video where it shows why you want to have a torque arm? Sat though the entire 13 minutes still don't know why you would want one over a three link.

Now that you have both seen the video and read Filip's reply do you now know? You can thank me later for bringing enlightenment to this dark corner. ;-)

But Filip himself just now said that the torque arm gives you the least amount of advantage with a car that has a stock ride height, relative to one that is lowered.

That's not to say that the TA won't bring any advantages to a stock ride height car. On that, I cannot say. I'd like Filip to chime in on what those advantages would be if you keep the rear suspension the same as stock as far as geometry goes.




Sure. I'm not arguing that there are no advantages to be had by lowering the car. But if you're really going balls to the wall, then you'll rip out the entire front suspension and replace it with a SLA suspension, just to get rid of the camber related compromises that come with a McPherson strut suspension. Done right, you'll even be able to locate the roll center exactly where you want it.

But here, we're talking about the rear suspension, and why you'd want to lower it. I suppose there might be some additional drag reduction in lowering the rear, but oddly enough, the first thing that'll be done after that is to add aero to the rear of the car which increases drag. I've no idea how much rear downforce you'd lose by lowering the rear of the car by a couple of inches. Having the front lower than the rear means the floor of the car is canted slightly, which will yield a low pressure area under the car, which in itself causes downforce. You'd lose some of that effect by lowering the rear.

My understanding of vehicle aerodynamics is that aerodynamics are the best with the front lowered at a rake. So from that perspective you would want a little bit more ride height in the rear than in the front. But if the rear is too high relative to the front then you obviously have center of gravity issues and problems with geometry on cornering etc. If you read Filip' s explanation, The torque arm is more effective with a lowered vehicle.

But Filip himself just now said that the torque arm gives you the least amount of advantage with a car that has a stock ride height, relative to one that is lowered.

That's not to say that the TA won't bring any advantages to a stock ride height car. On that, I cannot say. I'd like Filip to chime in on what those advantages would be if you keep the rear suspension the same as stock as far as geometry goes.


Sure. I'm not arguing that there are no advantages to be had by lowering the car. But if you're really going balls to the wall, then you'll rip out the entire front suspension and replace it with a SLA suspension, just to get rid of the camber related compromises that come with a McPherson strut suspension. Done right, you'll even be able to locate the roll center exactly where you want it.

But here, we're talking about the rear suspension, and why you'd want to lower it. I suppose there might be some additional drag reduction in lowering the rear, but oddly enough, the first thing that'll be done after that is to add aero to the rear of the car which increases drag. I've no idea how much rear downforce you'd lose by lowering the rear of the car by a couple of inches. Having the front lower than the rear means the floor of the car is canted slightly, which will yield a low pressure area under the car, which in itself causes downforce. You'd lose some of that effect by lowering the rear.


To be clear, I'm not disputing that there are advantages to lowering the car in the rear. I'm asking what those advantages are, especially in light of the geometry compromises that inevitably result.

KC , that is true which is why I deleted the comment. However all advantages are relative. When I first put the torque arm Watts link and control arms on my vehicle I was running the Boss 302 Springs. They were tall and soft. The torque arm was my friend not necessarily because my Springs were tall but because they were soft. So I was really referring to my own personal experience and it was incorrect with respect to the "tall" part. That being said if you want your stock ride height vehicle to drive a whole lot better put that cortex Watts link and torque arm on and it it'll be a different car. And you will notice its advantages much more then if you had coilovers already on cuz you will notice the difference in anti Squat and anti dive more on the stock Springs

 

[kcbrown]

My understanding of vehicle aerodynamics is that aerodynamics are the best with the front lowered at a rake. So from that perspective you would want a little bit more ride height in the rear than in the front. But if the rear is too high relative to the front then you obviously have center of gravity issues and problems with geometry on cornering etc. If you read Filip' s explanation, The torque arm is more effective with a lowered vehicle.

Right. That's my point. You lower the CG of the rear some, but it is minimal, and you now introduce geometry changes in the rear that you have to fix.

If lowering the rear simultaneously reduces the downforce (by reducing/eliminating the rake) and introduces geometry problems that you then have to correct, it raises the question of exactly how much benefit you'll wind up with in the end when you've done all that, compared with what you had before you did all that. Are you really going through all that effort for what amounts to a couple of inches (less than 10%) of CG drop, zero roll stiffness increase, and a reduction in downforce? That's something you'd want to do if you're competing, of course (you'd be using a wing in the rear to gain your downforce back), but then, if you're competing, you'd want that SLA suspension as well, no?


And that raises another question about the TA: how does it affect one's ability to throttle-steer the car?

 

[barbaro]

Dude seriously if you don't have any tech don't even acknowledge me as existing. You obviously have a vested interest in pushing Cortex shit. Give me a reason to run a TA over a (key words here) spherical bearing three link with proper geometry. Of course adding a torque arm, Watts and relo brackets, on top of dampers, springs and bars to a stock mustang will make the car work better. No one is debating that. Because from every video I see from those guys, that's what I see, their parts (which are quality pieces) added to a stock car. Let's see them take a sorted car such as Vorshlag's old car or Marks old car or even mine and show me how much faster it would be with a torque arm.

My Fox hopped like a motherfucker with a torque arm. Ended up putting autozone pads on the rear to basically take the braking out of it. If the S197 didn't have ABS or would too.

Since Filip is the chief engineer for racing teams that run at the highest level of racing that the s197 competes in I think he could do just that. I am sure that he could take any car that anybody on this forum runs and make it faster with his torque arm. And he explains why. With a torque arm you can run softer Springs and maintain better grip. There are people on here including Terry Fair that are running 800 pound Springs. Filip just explained why
there is no performance advantage from Running Springs over 600 pounds.

Now if you want to argue with the chief engineer for Rehagen and Roush racing, go ahead. But I ask you this, is there anybody on this forum that has done anywhere near the testing of the s197 more than Filip? Is there anybody on this forum who has a better education training and credentials then Filip?

A little bit before Filip was so important I saw what he was doing I bought his parts I thought they were great. I recognized the talent and ability. And so I listened to him and I didn't listen to any of you, most of whom ridiculed me in the most unflattering ways
So excuse me if I'm a bit chippy because I'm feeling pretty fucking Vindicated right now

Right. That's my point. You lower the CG of the rear some, but it is minimal, and you now introduce geometry changes in the rear that you have to fix.

If lowering the rear simultaneously reduces the downforce (by reducing/eliminating the rake) and introduces geometry problems that you then have to correct, it raises the question of exactly how much benefit you'll wind up with in the end when you've done all that, compared with what you had before you did all that. Are you really going through all that effort for what amounts to a couple of inches (less than 10%) of CG drop, zero roll stiffness increase, and a reduction in downforce? That's something you'd want to do if you're competing, of course (you'd be using a wing in the rear to gain your downforce back), but then, if you're competing, you'd want that SLA suspension as well, no?


And that raises another question about the TA: how does it affect one's ability to throttle-steer the car?

Dude Lol, you're all over the place. Lowering the car in both the front and the rear improve your center of gravity and even a one-inch drop makes a big difference in handling provided you correct the geometry which is easy enough to do. You keep talking about it like it's this big mess? It's not.

And of course An SLA front would be better, what does that have to do with anything? Is that an argument for not lowering the front of your car?

As for throttle steering, I'm not a good enough driver to do a whole lot of throttle steering and I dare people to throttle steer around the track I go to such as Willow Springs. I have seen people do it but I'm not throttle steering at 130 miles an hour around turn 8 and turn 9. However I am a good enough driver to do donuts and 2 break my back and loose for fun and the torque arm gives you excellent control over your back end. Between my torque arm and my Torsen t2r my car's a drifting machine if I want it to be. In fact I put a real stiff 26 millimeters sway bar on there and did just that.

 

[SoundGuyDave]

Sounds Guy Dave, thank you for thanking Filip. 1) Are you prepared to moderate your views with respect to torque arms on the s197 chassis? 2) are you prepared to stop mocking me for advocating it? 3) Are you prepared to thank me for bringing this issue to the fore so that you could have the opportunity to have direct discussion with Filip himself?. ;-)

1) I will moderate my views when I have been sufficiently convinced that there is sufficient benefit compared to a properly set up 3-link (all rod-end, maximized adjustment on the UCA).

2) No. Bring tech beyond "it's a supercharger for your suspension" and I'll stop.

3) No. I still feel that you are pushing forward an agenda that goes beyond simple presentation of knowlege and experience. I think that you pulled Filip into this mess only to support your agenda, not because you think he would be a fantastic resource to the S197 community. That he could be that fantastic resource, I have no doubt.

Too many times you've come across with the attitude that if you don't have it on your car, it's worthless, and if somebody doesn't have something you do, they're idiots. With no hard facts to back it up. When pressed for something that isn't purely subjective, like lap times, data acquisition streams, or the like, you backpedal into ad hominem attacks or straw man arguments, and that's just not something that works around here.

I welcome Filip with open arms. I have buddies that I race with that use his products, and the build quality is excellent.

I just think the jury is still out on the TA situation pending further discussion of some of the fine points. The devil truly is in the details.

Since Filip is the chief engineer for racing teams that run at the highest level of racing that the s197 competes in I think he could do just that. I am sure that he could take any car that anybody on this forum runs and make it faster with his torque arm. And he explains why. With a torque arm you can run softer Springs and maintain better grip. There are people on here including Terry Fair that are running 800 pound Springs. Filip just explained why there is no performance advantage from Running Springs over 600 pounds.

From my own testing, though, I can tell you categorically that I achieved faster lap times coupled with reduced outside-edge wear running 750lb springs than I did with any of the lighter stuff I tried previously. I keep upping the spring rate and lap times drop, and the tires last longer. This is not an opinion, I have the numbers to back up that assertion. This has NOTHING to do with the rear suspension geometry, and everything to do with camber-gain in roll up front. If I can pull 1.5G laterally, I will. That is going to impose a given amount of load increase on the outside tire (moderated by the anti-sway bar, of course), which will in turn result in that corner of the suspension compressing. It compresses less with heavier springs than with lighter ones. This, in turn, keeps the front suspension in a more consistent range of camber-gain. That keeps the static negative camber requirement lower, which means that you get all the cornering grip without sacrificing as much contact patch under braking. This is on a strut car, with all the bells and whistles to correct the geometry after lowering, and camber maxed out without cutting the towers. I used to drive through a set of R6s up front in about 3.75-4 hours, down to the cords on the outside shoulders. Now, I can get a tick under 5 hours, the temps are much closer to even, and I start to cord the tires pretty much across the face, rather than on one edge.

I would be interested to hear how Filip's setup philosophy would handle this very real-world problem. And no, before you get in a huff, Barbaro, that was not a challenge, that was genuine curiosity. Terry, love him or hate him, has done a LOT of publicly-documented testing. I've done a lot of private testing, and we've both come up with the same issues and the same basic solution. His build is heavier, makes more power, and has an aero component to it, but we both find that heavier front springs make the car faster. I can also say that my tires last longer with the heavier springs, as well, in sustained runs. Now, Filip is saying the exact opposite. I don't doubt his results, but I question what the other setup changes were to get that result.

Basic theory tells you that all things being equal, you want the softest springs on the car that you can possibly have, as long as the car stays off the bump-stops (or at least the high-density portion of them). As soon as you factor in the geometry changes under suspension deflection in a strut-based car, though, compromises need to be made.

 

[barbaro]

1) I will moderate my views when I have been sufficiently convinced that there is sufficient benefit compared to a properly set up 3-link (all rod-end, maximized adjustment on the UCA).

2) No. Bring tech beyond "it's a supercharger for your suspension" and I'll stop.

3) No. I still feel that you are pushing forward an agenda that goes beyond simple presentation of knowlege and experience. I think that you pulled Filip into this mess only to support your agenda, not because you think he would be a fantastic resource to the S197 community. That he could be that fantastic resource, I have no doubt.

Too many times you've come across with the attitude that if you don't have it on your car, it's worthless, and if somebody doesn't have something you do, they're idiots. With no hard facts to back it up. When pressed for something that isn't purely subjective, like lap times, data acquisition streams, or the like, you backpedal into ad hominem attacks or straw man arguments, and that's just not something that works around here.

I welcome Filip with open arms. I have buddies that I race with that use his products, and the build quality is excellent.

I just think the jury is still out on the TA situation pending further discussion of some of the fine points. The devil truly is in the details.

And neither do you have any hard evidence to back you up Sound Guy Dave. You have never had a shred of data or hard evidence to back you up. whether it was about coilovers punching through the shocktowers or torque arms you have contributed much misinformation here.

You have never cited one relevant fact to support your opinion. You dissed the cortex torque arm without ever having driven one. You spoke from a complete state of ignorance. I at the very least, had personal knowledge of what I was talking about, regardless of my enthusiasm, You relied on what exactly? You had neither data or personal knowledge? Yet you have the stones to criticize me because I don't have before and after lap times.

Filip was on this forum and you had the opportunity to address him directly on the above points and you passed figuring you could push me around because I am not an engineer and I don't teach driving school? Step up and show the strength of your convictions like you did with me.

I believe it was you who with others (Vorschlag) were spreading misinformation about the cortex rear coilovers being prone to failure by punching through the shock tower. I called you on it and I asked you to show even one example and you could not. And neither could anybody else. Where was the data to support your opinion then? You had none then. And you have none now. Like everyone else you bring your own prejudices to the table and not a whole lot to support it. You are guilty of what you accuse others of.

And even now you betray your doubt with this dissembling backpedal: " I just believe the jury is still out on the torque arm situation pending . . ." Really? Because that's not what you were saying when you and Terry Fair were deriding the torque arm that was put on that New York super build. Because then, you and Terry Fair basically were saying they were stupid for putting a Griiggs torque arm on their car!

I have never been here too push cortex I'm not a representative for cortex and because of my prickly personality I would be a shitty representative for cortex. That being said they make the best most up to date stuff. What am I supposed to do deny it so that Terry Fair can sell more shocks? Because lets face it that's who you have been pushing with your thousands of posts.

So if you truly do welcome Filip then you can thank me because if it wasn't for me raising this issue he wouldn't be here. And if it was up to you he wouldn't be here either, challenging the Vorschlag party line.

 

[Norm Peterson]

Norm, of all your arguments this is the most disingenuous one. You are an engineer and you know if brake hop is going to be an issue at all it's completely dependent upon the geometry of the vehicle and the torque arm relative to it.

So . . . you're not an engineer and you're trying to tell me what is and what is not involved in an engineering problem?
Big hint from suspension 101 . . . everything affects everything else.


Norm

 

[barbaro]

So . . . you're not an engineer and you're trying to tell me what is and what is not involved in an engineering problem?
Big hint from suspension 101 . . . everything affects everything else.


Norm

Did Filip address this issue to your satisfaction?

 

[SoundGuyDave]

Barbaro,

Yes, you did a good thing bringing Filip into this forum. We can all learn something from him, someone who is in the trenches AND has the educational and experiential background to provide meaningful comment. Sadly, though, you felt the need to crow about it here, and here. I probably missed a few, but it just really paints the picture of how rough it really is to be you. You bought some parts for your car, which by definition (in your mind) makes them the only, and most optimal possible choice, and anybody who dares to disagree with you, for any reason, is definitively wrong. Never mind their engineering credentials, nor their practical experience, nor overwhelming evidence to the contrary, they are wrong. Because you said so.

Well, welcome to the world outside of nursery school. Things are not clear-cut. There is rarely a single best solution for any given problem. Learn to deal with that and your adult life might just get smoother for you.

Stop citing comments out of context. Stop believing that just because you say so, it necessarily follows that it is incontrovertible fact. Start being skeptical of claims, and start LEARNING enough to argue a case on it's merits, rather than skirting the issue with attack-tactics. Feel free to disagree with me, or Norm, or anybody else, but be ready to support your argument with facts, and not opinions.

You've specifically attacked my credibility in post 41 of this thread, but have not one single leg to stand on yourself. If your vaunted Torque Arm was SUCH a game changer, why isn't it essentially spec equipment on nearly every S197 American Iron build out there? It's been available since shortly after the chassis launched. If it's manna from heaven, then why isn't everybody running one? Are you the only enlightened one on the planet? Filip is a solid engineer. I have nothing to argue against his qualifications or experiences. That said, if you ask six engineers how to solve a problem, you'll get seven answers. Is any one of them categorically wrong? Is one dramatically superior to the others? If the TA is just such a blindingly, obviously, categorically superior design to the 3-link, then why did Ford not equip the S197 with one from the factory? If it's better on the street, as was asserted, AND better at the dragstrip, AND better on a race track, then why didn't they hang it on the car in the first place?

I'm pretty much done debating specifics with you, primarily because you have no clue what you're talking about 99.97% of the time. And I'm probably being generous with the 0.03%. You say I provide no hard data? I've posted lap time differentials. I've posted in-car vids before and after mods. What have you provided other than lame excuses and pure hyperbole? "Supercharger for your suspension" is about as deep as you get. You neither have, nor want any in-depth understanding of how your kit works; but because you bought it and like it, so must we all. You say I push Vorshlag (please note the spelling), yet I've had online knock-down arguments with Terry. I don't always agree with his conclusions or opinions, HOWEVER, I respect his methodology and the openness with which he supplies raw data, sometimes to his own detriment.

Again, I'll ask, what have you provided?

You brought Filip to this forum. For that I thank you. Filip posted a well thought-out presentation on his view of the TA suspension and it's benefits and drawbacks. Norm had a question (or two, or three), and I also posed a question. If you had bothered to read and digest what was written, you wouldn't have said that I had the opportunity to ask a question and passed. You wouldn't have asked if Norm's questions were answered to his satisfaction, since there was no answer posted after he posed his question. But you didn't stop to read and comprehend what was written. Your high horse was galloping too fast for that.

THAT is why you draw so much flak on this forum.

Quick primer on the scientific method:
Problem: Define what it is, exactly, that you are trying to discover or solve.
Hypothesis: What you believe the solution to be, after research and thought.
Experiment: Define and carry out a series of tests with ONLY ONE variable changed in each test run.
Analysis: Study the data you collected in your experiment, look for possible errors in data collection, identify trends or specific results. This is necessarily a comparison of "before" and "after" in some form or another.
Conclusion: Based on the analysis of your data, draw a conclusion of your hypothesis under test.

Until you understand that, and start to apply it, you have no data points to provide. If I run a race and change tire compounds midway, I have valid data. Lap times on tire A versus lap times on tire B. Bolting a part on your car and saying "This rocks!!" is not data, it's an opinion. Please learn the difference between the two.

 

[Whiskey11]

FWIW, when I went to the TA on my car, ST did not have relocation brackets and LCA's. I did it specifically because it brought my %AS from the low 20's up into the upper 30's wihout ever touching the LCA's. When I finally got my LCA brackets in ST I was able to add even more %AS and ended up at %56 without ever really testing higher settings. The car was absolutely silly to drive fast. Basically toss and mash and the car would hook up and go.

The new car is... for a lot of reasons... far less forgiving.

I would also agree that spring rates are going to depend HEAVILY on plenty of other factors. How low you are, what geometry corrections you've done, what tires you have, how much aero you have, etc. When I went from 440 up front to 550 up front there was a significant reduction in camber loss while cornering which led to faster lap times and longer lasting street tires in autocross.... It really still wasn't enough though as I was seeing tremendous outside shoulder wear and tire temps that were not even across the tire. I DID reach the point where adding any more spring up front would mean less bar (not necessarily a bad thing) to keep the balance the same as any stiffer out back and I'm pretty confident the car would have been a nightmare to drive.

 

[kcbrown]

Dude Lol, you're all over the place. Lowering the car in both the front and the rear improve your center of gravity and even a one-inch drop makes a big difference in handling provided you correct the geometry which is easy enough to do. You keep talking about it like it's this big mess? It's not.

The point is that you have to make some corrections to the geometry in order to deal with lowering the rear in the first place, and my question is about how much of an improvement you really see from lowering the rear compared with running spring rates, sway bar rates, etc. that are optimal without lowering it. It factors into the next question (see below).

And of course An SLA front would be better, what does that have to do with anything? Is that an argument for not lowering the front of your car?

No. It's to put the entire thing into context. In the absence of a budget, when the fastest lap times are what one is after, then it follows that one will spend money on the SLA suspension to replace the strut-based suspension because doing so gets you much better control over the camber curve and, simultaneously, allows you to set the roll center to something better suited to racing (that latter assumes that the design is done with racing in mind, but that's a pretty reasonable assumption).

To do anything less means that one is making budget-based compromises, which means that one is going to be concerned with the best bang for the buck.

So my question in the latter context is: how does lowering the CG by less than 10%, while simultaneously having no impact on the roll center and causing a reduction in downforce, which requires spending money to correct the geometry in the process, provide more bang for the buck than would spending that money on, say, better coilovers, or a Watts link, or any of a number of possible options?

It looks to me like lowering the rear suspension may well be the last thing on the list in terms of gains to be had versus the price. I want to learn why it's not.


Do understand: it is in my nature to question everything. I do that because it's the most effective way I know of to reveal and get past assumptions that have been made. Assumptions can be incorrect, and it is not until one knows why something is done a certain way that one can know whether or not one should do things in that same way in the circumstances one finds himself in.

As for throttle steering, I'm not a good enough driver to do a whole lot of throttle steering and I dare people to throttle steer around the track I go to such as Willow Springs. I have seen people do it but I'm not throttle steering at 130 miles an hour around turn 8 and turn 9. However I am a good enough driver to do donuts and 2 break my back and loose for fun and the torque arm gives you excellent control over your back end. Between my torque arm and my Torsen t2r my car's a drifting machine if I want it to be. In fact I put a real stiff 26 millimeters sway bar on there and did just that.

That's good to know. I have the Boss 302 springs (standard up front, Laguna Seca in the rear) and the 26mm sway bar, and it really made the rear come alive as well as substantially improving the turn-in, enough so that I don't notice a response delay in the suspension anymore.


By the way, I don't know what you did to get Filip here, but good on you for doing so! I, for one, hope to learn a lot and I think this will be an even better place for it.

 

[barbaro]

I am guilty of communicating the subjective improvements the Cortex Rear End provided. It is you who is quoting out of context what i said, because as you well know, I said a lot more than "supercharging the suspension" And I do stand by that incidentally, in that it has the comparable effect on the suspension as a supercharger has on acceleration.

If Filip explained to you why that is to your satisfaction or not, I don't know or really care. I am sure Bruce Griggs could come on here and give you a similar dissertation. You denied my subjective experience and you expected to me to back down and why would I back down from something i truly believed? When I didn't back down there was much whaling and nashing of teeth and even now it threatens to devolve out of control because I challenged some bullshit orthodoxy. Whether it was coilovers allegedly punching through shocktowers or the plain superiority of a torque arm, whatever my meager credentials, I have advanced the knowledge that you have tried to prevent.

And had I not challenged it, you would not have the opportunity to communicate directly with one of, if not the, leading Race Team Engineers in the highest level of Mustang Racing. I was his advocate early and you all shot me down for it. Now you speak in measured tones when he addresses you. I get immense satisfaction out of that. So I feel vindicated. And please feel free to address with Filip how many coilovers of his have punched through shocktowers. Because there is much misinformation to correct.

Debate is good and this is the reason.