Cortex Torque Arm Racechrono Track Review

[Norm Peterson]

Norm, how do you get any work done?

If you must know, I'm 65 and in limbo somewhere between being laid off and semi-retired. So yes, I do have a lot of time for this sort of thing. As I have had before, during various other periods of unemployment spread out over the past dozen years or so.

Deal with it.

Your numerous and predictably detailed responses to everyone of my posts actually elevates my profile beyond what is justified. You doth protest too much.

Unlike yourself, I do not expect anybody to accept on faith anything that I might post, and I won't ever demand that they do. Even you deserve some inkling of my generally technical thought process.

My review was of the whole system. Whiskey 11's is mixing and matching in a highly unusual way in order to fit into his autocross rules. It is not a fair evaluation of my evaluation. He nor you have what I have. So all you can talk is a lot of nonsense because neither of you has personal experience with what I have. And all the engineering background in the world cannot substitute for personal experience.

So just because Whiskey's experience to date doesn't exactly fit your anticipated vision of an "ah-ha" moment, you're going to try to discredit his opinions from the get-go? Way to go, sport, if the help is less than what you hoped for - just take a few pot-shots at it. Excellent strategy.

You don't have my car and you don't have my rear grip package and you cannot fairly evaluate my evaluation with your bench racing reverse engineering.

No, I can't evaluate your car, but I certainly can critique your evaluation and ask for clarifications that would help me to understand the reasons for your satisfaction. You can either help here or not. Your choice. Big hint - help has to be technically oriented contributions, not defensive maneuvering.

More accomplished automotive engineers / racers than anyone here believe in this system (Griggs and Filip). I believe in it because it works for me.

Engineers are entitled to their preferences as well. This is not a matter of right vs wrong as you keep trying to make it out to be.

I have tried the oem three link design. I have tried aftermarket upper control arms and different spring packages too numerous to mention here. Everything sucks compared to Cortex's rear grip package. You and others have attacked me for the opinion. I understand. I am new to you. I overused superlatives perhaps.

You being new to me does not matter in the slightest. I cut newbies more slack than average.

But my opinion is stronger now than ever. Whether you have faith in my truth matters little to me.

You keep using this line rather than attempt to gain some technical understanding of what you have and why it might be working out better for you. That's the kind of explanation that would have been received a whole lot better. Instead, you posted

I don't give a fuck about the why of it.

when the knowing of why is exactly what people want and/or need to be reading here.

Sure, you're entitled to your opinion. We all are. But don't keep bleating faith and my truth when you can't answer the technical questions. Just say "I don't know" and either let it go or <gasp> learn a little of the technical side so that you can make useful technical contributions to this discussion.

I really do understand that you're not a technical guy, so it's entirely reasonable that you don't understand how somebody with a technical oriented mindset can apply general concepts to specific situations.

I've even suggested a couple of things that would tend to support your claims (the onus is on you to go find them now, as I won't be repeating them in this thread).

But while I may be outposted, I will not be shouted down or bow to anybody's alleged superior experience because no one here has superior experience because no one has made my precise modification and driven it as I have.

Bring the tech, let it be discussed in a technical environment, and maybe you won't feel that way. We might all learn something.

The real people who know aren't on here and other forums accumulating thousands of posts as you have.

So you've been looking for something to shoot me with (it's a bit over 19000 to date, spread out over a dozen years or so). Here, I'll even help you find some more, even though I'm not all that hard to find. Forums with at least 20 posts. Unraveling my abbreviations is on you.
Mustang S197 AllFord M6G NJStang Stangfix Corral CC PT Latg ETips MCSS Malibu Camaro5 FRRAX 3Gen CZ28 Philly SCCA Max LGT Probe 626

Now go find me a post of mine where there wasn't at least a scrap of technical content or other help contained within it and don't come back at me until you do. I dare you. Quote it with a means of getting back to it and I'll probably be able to tell you the context with which it was written.

The people who know are out on the track and working under a lift. I followed their lead rather than the forum mavens. I could not be happier. And if this irritates some of you; that is more unfortunate for you than it is for me.

Do not underestimate the benefit of having an engineering outlook when it comes to either of those avtivities. I'm afraid you don't know what you're unfortunate enough to not know, else you'd have a slightly different point of view.


Norm

 

[barbaro]

I dont think so. The only thing that has wowed me is the increase in gear noise. Fair that it might be installer error.

I have a watts linkage already, and the TA by itself has not transformed my car in the way coilovers, good wheels and tires and my watts link have. The stability a watts adds in autocross is immediately noticeable, the TA is more suttle. I may enjoy it more the more I drive it which is happening a lot these next few weeks.

Also, why do you insult Norm? He has the posts he has because he is extremely helpful and his contribution to this forum is a thousand fold what yours is and he has both experience and suspension theory to back up his posts.

Because Norm is condescending to me, He outright says I do not understand this or i do not understand that etc. . . . . To have your personal experience constantly discounted as irrelevant is more insulting than anything I have ever said to Norm in reply.

My experience is just the opposite of yours actually. I had a Cortex Watts link prior to installing the torque Arm and rear lower control arms. I noticed the Watts link to be the more subtle improvement. I noticed it but was not blown away by it. The dramatic improvement came about with the installation of the Torque Arm and lower control arms. I have had heim jointed lower control arms before and while they gave me some noticeable improvement it was not dramatic. Consequently, the great improvement that I noticed in anti squat, nosedive, rear end grip and control, quieting of the chassis's vertical movement and ride quality in general I attributed to the Torque arm.

Take into account also that I was running OEM Boss 302 springs. If you already had stiffer springs then you have already improved much of the antisquat and nosedive leaving less room for noticeable gain through installation of the Torque Arm alone. I switch my springs out every couple months or so, testing different combinations. I still prefer the Boss 302 OEM package as it leaves my car loose, but with the torque arm, controllable. (Although I acknowledge track driving requires much stiffer springs) But ride quality is important to me and a loose but controllable car is a fast car at the track. This is probably not so for auto cross where the track is narrow and the tolerances tight so there does not seem to be room for power oversteer around corners even if it is controllable.

When I explained my setup to Filip he told me the Torque arm was designed just for my situation, to give better rear end control without having to resort to stiffer less comfortable springs. You indicated you noticed and in part measured improvements in anti squat, nose dive and oversteer control. That in and of itself seems to me to be extraordinary given you only replaced one link in your suspension.

I did not notice any NVH increase at all due to the torque arm although there was the predictable chatter from the heim jointed lower control arms over small bumps. I reiterate that I was very skeptical. You will not and have not seen me post glowing reviews about any other particular manufacturer or part on my heavily modified car. No threads exclusively extolling Comp cams. (although they worked for me) No Threads extolling Livernois ported heads (although they worked for me) No threads indicating Michelin Super Sports are great, although they are for the street and are pretty good for a street tire at the track. I have posted in several places indicating aftermarket UCA suck, because in my experience they do. As Terry Fair is my witness, I have not gotten too much grief about that.

The only parts I can say unequivocally are superior to the competition in performance benefit are the Cortex Rear Grip package and the Tiger racing hood. I was very skeptical about the torque arm benefits and it took some convincing for me to do it. So to be portrayed as some Fan Boy or Schill has stuck in my craw a bit. I test everything I put on my car on the street and at the track. I have wasted more money than I care to think about and it was not my desire to mislead anybody to do the same.

I don't say that Cortex's coilvers are better than Vorschlag's coilovers. I don't say that my MM caster camber plates are better than Vorschlag's or Ground Control's caster camber plates. I can't say unequivocally that the Cortex Watts Link gives you a performance advantage over any other. (although I do and have said it is a very very nice piece) Because I do not know any of those things to be true.

All I am saying is for me, the Cortex rear grip package including the Torque Arm, cured all that was wrong with my car. Many others agree with me but very few post about it. Only an infinitesimal number of people post about their modifications compared to the number that actually make modifications. Whiskey, you have your own journey and you will and are discovering truths as applied to your setup. I do not discount your personal experience and respect it a great deal. But you have a significantly different setup from me and drive your car for a different purpose. I am not surprised or dismayed by your experience. It is just not my experience.

 

[barbaro]

If you must know, I'm 65 and in limbo somewhere between being laid off and semi-retired. So yes, I do have a lot of time for this sort of thing. As I have had before, during various other periods of unemployment spread out over the past dozen years or so.

Deal with it.



Unlike yourself, I do not expect anybody to accept on faith anything that I might post, and I won't ever demand that they do. Even you deserve some inkling of my generally technical thought process.




So just because Whiskey's experience to date doesn't exactly fit your anticipated vision of an "ah-ha" moment, you're going to try to discredit his opinions from the get-go? Way to go, sport, if the help is less than what you hoped for - just take a few pot-shots at it. Excellent strategy.



No, I can't evaluate your car, but I certainly can critique your evaluation and ask for clarifications that would help me to understand the reasons for your satisfaction. You can either help here or not. Your choice. Big hint - help has to be technically oriented contributions, not defensive maneuvering.




Engineers are entitled to their preferences as well. This is not a matter of right vs wrong as you keep trying to make it out to be.




You being new to me does not matter in the slightest. I cut newbies more slack than average.




You keep using this line rather than attempt to gain some technical understanding of what you have and why it might be working out better for you. That's the kind of explanation that would have been received a whole lot better. Instead, you posted

when the knowing of why is exactly what people want and/or need to be reading here.

Sure, you're entitled to your opinion. We all are. But don't keep bleating faith and my truth when you can't answer the technical questions. Just say "I don't know" and either let it go or <gasp> learn a little of the technical side so that you can make useful technical contributions to this discussion.

I really do understand that you're not a technical guy, so it's entirely reasonable that you don't understand how somebody with a technical oriented mindset can apply general concepts to specific situations.

I've even suggested a couple of things that would tend to support your claims (the onus is on you to go find them now, as I won't be repeating them in this thread).



Bring the tech, let it be discussed in a technical environment, and maybe you won't feel that way. We might all learn something.




So you've been looking for something to shoot me with (it's a bit over 19000 to date, spread out over a dozen years or so). Here, I'll even help you find some more, even though I'm not all that hard to find. Forums with at least 20 posts. Unraveling my abbreviations is on you.
Mustang S197 AllFord M6G NJStang Stangfix Corral CC PT Latg ETips MCSS Malibu Camaro5 FRRAX 3Gen CZ28 Philly SCCA Max LGT Probe 626

Now go find me a post of mine where there wasn't at least a scrap of technical content or other help contained within it and don't come back at me until you do. I dare you. Quote it with a means of getting back to it and I'll probably be able to tell you the context with which it was written.



Do not underestimate the benefit of having an engineering outlook when it comes to either of those avtivities. I'm afraid you don't know what you're unfortunate enough to not know, else you'd have a slightly different point of view.


Norm

Norm, again? Sometimes you need to let things go. You do realize by responding to my every post without exception you have lifted my profile, which is the opposite of what you intend to do I am sure. You have your acolytes. I am not one of them. Accept that and move on. I am comfortable just agreeing to disagree without going on an and on about it ad infinitum. Also, the most important information in making an evaluation of handling benefits is what is communicated through the steering wheel and the seat of your pants. I have the benefit of experiencing that with respect to these specific modifications. You do not. You attack my views on the basis of technical analysis I cannot provide. But you cannot substantiate your views with the subjective experience you lack. So we are at an impasse. One I am more comfortable with than you apparently.

 

[Norm Peterson]

Why didn't you say this ↓↓↓ in the first place? . . . . . . . . but geez, then I'd have about 40 less posts . . .

I had a Cortex Watts link prior to installing the torque Arm and rear lower control arms. I noticed the Watts link to be the more subtle improvement. I noticed it but was not blown away by it. The dramatic improvement came about with the installation of the Torque Arm and lower control arms. I have had heim jointed lower control arms before and while they gave me some noticeable improvement it was not dramatic. Consequently, the great improvement that I noticed in anti squat, nosedive, rear end grip and control, quieting of the chassis's vertical movement and ride quality in general I attributed to the Torque arm.

Take into account also that I was running OEM Boss 302 springs. If you already had stiffer springs then you have already improved much of the antisquat and nosedive leaving less room for noticeable gain through installation of the Torque Arm alone. I switch my springs out every couple months or so, testing different combinations. I still prefer the Boss 302 OEM package as it leaves my car loose, but with the torque arm, controllable. (Although I acknowledge track driving requires much stiffer springs) But ride quality is important to me and a loose but controllable car is a fast car at the track. This is probably not so for auto cross where the track is narrow and the tolerances tight so there does not seem to be room for power oversteer around corners even if it is controllable.

When I explained my setup to Filip he told me the Torque arm was designed just for my situation, to give better rear end control without having to resort to stiffer less comfortable springs. You indicated you noticed and in part measured improvements in anti squat, nose dive and oversteer control. That in and of itself seems to me to be extraordinary given you only replaced one link in your suspension.

I did not notice any NVH increase at all due to the torque arm although there was the predictable chatter from the heim jointed lower control arms over small bumps. I reiterate that I was very skeptical.

The only parts I can say unequivocally are superior to the competition in performance benefit are the Cortex Rear Grip package and the Tiger racing hood. I was very skeptical about the torque arm benefits and it took some convincing for me to do it. So to be portrayed as some Fan Boy or Schill has stuck in my craw a bit. I test everything I put on my car on the street and at the track. I have wasted more money than I care to think about and it was not my desire to mislead anybody to do the same.

I don't say that Cortex's coilvers are better than Vorschlag's coilovers. I don't say that my MM caster camber plates are better than Vorschlag's or Ground Control's caster camber plates. I can't say unequivocally that the Cortex Watts Link gives you a performance advantage over any other. (although I do and have said it is a very very nice piece) Because I do not know any of those things to be true.

All I am saying is for me, the Cortex rear grip package including the Torque Arm, cured all that was wrong with my car. Many others agree with me but very few post about it. Only an infinitesimal number of people post about their modifications compared to the number that actually make modifications. Whiskey, you have your own journey and you will and are discovering truths as applied to your setup. I do not discount your personal experience and respect it a great deal. But you have a significantly different setup from me and drive your car for a different purpose. I am not surprised or dismayed by your experience. It is just not my experience.

Norm

 

[55R2014]

Well as a prelim analysis, we have "teething issues" in the form of a really vocal chuckle over bumps. I have chased every bolt in the suspension with the torque wrench and it still does it so I think it is something else like the driveshaft. It happens at all speeds below 65mph. It also happens with gas/decel and shifting. No noise while rolling back and forth. Could be rear control arm bushings allowing more slack in the driveshaft... I dunno.

Driving impressions are mostly positive, it definetely works as advertised. Power down is really nice and no brake hop. Mild increase in NVH neglecting the clunk, tons more diff noise but nothing unbearable. Headed home to figure some of the noise out now after checking in. Hopefully I can get it squared away tonight.

The "chuckle" and clunking noise in the driveline I have on my car as well but it has been there since I took delivery of the car from the dealer. I was thinking it was slop in the driveline such as the 2 piece drive shaft or the play in the third member set up from the factory. I have ridden in a couple other 2013 Premium Mustangs that have the same issue as mine but not as loud. One is a Track Pack car with the 3:73 gears, the other has 3:55 gears.

I did get increased NVH when I added the CorteX watts link to the rear end. It is not loud but I did notice it. The pitch in the whine increases with speed increase and vice versa. If I listen for it I can hear it, otherwise I don't notice it especially with the stereo on. The CorteX watts link cover has two preload adjusters that can be set to load the caps in the third member. I thought those were contributing to the added NVH. After backing them off so they don't touch the caps, the NVH did not go away or decrease. I have to say that I also added the coilovers and lower control arms with rod poly bushings on the chassis end and rod-ends no the other end, so that may have contributed to the NVH. All of this was 2000 miles before I added the torque arm.

After adding the torque arm the the NVH did not change. I still have all of the same clunking noises that I did when I took delivery of the car. The car drives, feels, and handles so much better than it did with he factory set up, it is worth the extra noise.

 

[Whiskey11]

The "chuckle" and clunking noise in the driveline I have on my car as well but it has been there since I took delivery of the car from the dealer. I was thinking it was slop in the driveline such as the 2 piece drive shaft or the play in the third member set up from the factory. I have ridden in a couple other 2013 Premium Mustangs that have the same issue as mine but not as loud. One is a Track Pack car with the 3:73 gears, the other has 3:55 gears.

I did get increased NVH when I added the CorteX watts link to the rear end. It is not loud but I did notice it. The pitch in the whine increases with speed increase and vice versa. If I listen for it I can hear it, otherwise I don't notice it especially with the stereo on. The CorteX watts link cover has two preload adjusters that can be set to load the caps in the third member. I thought those were contributing to the added NVH. After backing them off so they don't touch the caps, the NVH did not go away or decrease. I have to say that I also added the coilovers and lower control arms with rod poly bushings on the chassis end and rod-ends no the other end, so that may have contributed to the NVH. All of this was 2000 miles before I added the torque arm.

After adding the torque arm the the NVH did not change. I still have all of the same clunking noises that I did when I took delivery of the car. The car drives, feels, and handles so much better than it did with he factory set up, it is worth the extra noise.

The two piece is really awful for clunks but I am just not sure that is the cause. I would think that once power is applied that you would stop getting clunks. This noise happens primarily under power at speed and sometimes with the clutch in. No noise while coasting in gear, dead silent even on thesame stretch of road.

Either the mount isnt tight or something in the driveshaft is contacting the TA frame under load or maybe the exhaust (unlikely) is or a bearing is destroyed.

Day 2 was very similar to day 1. I like the feeling of the oversteer control but I was hoping for better/earlier power down and I am just not sure I am getting that. People keep saying the car is fast on course and looks good but the times are not showing it...

 

[Norm Peterson]

You probably need a little more seat time with it to get used to its slightly different nuances.


Norm

 

[Whiskey11]

You probably need a little more seat time with it to get used to its slightly different nuances.


Norm

And ohh boy is there A LOT of that coming up! Test'n'Tune this Saturday, Solo event on Sunday, Evo Test'n'Tune at Nationals on Sunday and my Nationals runs!

Norm, does it make sense to have more oversteer from a Torque Arm setup? It's hard to use previous generation cars as an "example" since so much of their stock stuff is awful but I would expect a touch more from the higher antisquat, unless of course that shocked the tires loose, could quite easily be my problem here.

I'm going to try a stiffer setting on the front bar (yes, fixing the problem at the wrong end of the car) as well as removing the rear bar entirely at the test'n'tune to see if that helps. I'm not messing with the Watts link at the T'n'T since it's such a PITA to move the bolt on now that the bolt is in the upper most position. I don't want to get rid of it the oversteer, I just want a touch less of it. The stiffer front bar should minimize body roll too!

 

[sheizasosay]

Norm, does it make sense to have more oversteer from a Torque Arm setup? It's hard to use previous generation cars as an "example" since so much of their stock stuff is awful but I would expect a touch more from the higher antisquat, unless of course that shocked the tires loose, could quite easily be my problem here.

Curious what Norm says aswell, but I would think if you had 37%AS as you suspect, then "shocking" the tires would not seem to be a strong possibility. That or your numbers are off in the "more AS" direction.

 

[Norm Peterson]

More anti-squat = less squat under any given amount of acceleration, which also changes where the car is operating on the axle roll steer curve. Greater amounts of squat from any given ride height translate to a more understeerish rear axle steer contribution (this would be the OE 3-link behavior). Less squat would translate to less understeerish axle steer behavior, which would feel like oversteer by comparison.

I have a strong suspicion that as long as the car is still rolled there exists some difference in the anti-squat value for the inboard and outboard tires, which may have some indirect influence as well. Something along the lines of short-lived differences in tire bite causing a transient yaw moment about the car's CG (plan view), perhaps.


On edit, those anti-squat values in the earlier post (~19% and ~31%) seem a little on the low side.


Norm

 

[Whiskey11]

More anti-squat = less squat under any given amount of acceleration, which also changes where the car is operating on the axle roll steer curve. Greater amounts of squat from any given ride height translate to a more understeerish rear axle steer contribution (this would be the OE 3-link behavior). Less squat would translate to less understeerish axle steer behavior, which would feel like oversteer by comparison.

I have a strong suspicion that as long as the car is still rolled there exists some difference in the anti-squat value for the inboard and outboard tires, which may have some indirect influence as well. Something along the lines of short-lived differences in tire bite causing a transient yaw moment about the car's CG (plan view), perhaps.


On edit, those anti-squat values in the earlier post (~19% and ~31%) seem a little on the low side.


Norm

Yeah I think I get it. I just figured that between the whole "Pinion gear climbing ring gear" reaction of a torque arm + IC location would translate to much greater power down on exit to the point of more understeer?

Here are my measured pick up points for the LCA's:
LCA Chassis: 5.5625
LCA Axle: 7.8125

That came to a drop of 2.3175" at the chassis end over your stock numbers. Tires are 265/40/18 which are an inch shorter overall than stock so the axle pick up point is about a half inch (I actually calculated it from your numbers at .4375 which seemed low to me). Assuming that the UCA mount moves the same distance as the LCA chassis side that would put the chassis side mount at 17.0625" and the axle side (moving the same distance as the LCA pick up point of .4375) at 20.1925. I wasn't sure where to put the CG, 21" is what you listed in a different thread for a stock car which I'm sure got lower from lowering the car. My "fender drop" measurements say about 1.625" drop in the front and the car is level so I believe I used the difference of 21 and 1.625 as the CG height to obtain those numbers.

Torque arm static number was achieved by changing the UCA inclination until the IC was at 44.5" which might be about a half inch short still of the IC location (so the numbers are higher than they should be).

Do you see any flaw in the static %AS numbers for either the 3 link or the TA in this case?

 

[barbaro]

"The suspension functions better as a whole with the torque arm. The suspension pivot point is moved to the center of the car and gives the 3 points of pivot (lower control arms and torque arm pivot point) a greater triangular geometry. The Torque Arm eliminates the upper control arm. The torque arm provides for greater lateral grip in addition to greater forward bite. The simple addition of the torque arm also creates better "anti-squat" geometry and the the car is more level and planar under load and at WOT.

I have a number of customers running just the torque arm with standard Ford Racing suspension mods. The one comment I always get is that the car feels more controlled. One particular comment from a customer in South Carolina who has a long circular on ramp to the highway that he takes daily. Before the suspension mods there is a crack in the on ramp that would unsettle the car and really get the rear end loose. Now he just drives over it and doesn't feel a thing. He literally stays in the power. He's also got a Kenne Bell 2.8 and makes over 700 at the wheel.

The watts link only further compliments the torque arm by squaring the rear end and eliminating the panhard bar.

We've had customers with IRS suspensions remove the IRS, got to the Griggs system and their lap times are faster."

Van
Revan Racing

 

[SoundGuyDave]

"The suspension functions better as a whole with the torque arm. The suspension pivot point is moved to the center of the car and gives the 3 points of pivot (lower control arms and torque arm pivot point) a greater triangular geometry. The Torque Arm eliminates the upper control arm. The torque arm provides for greater lateral grip in addition to greater forward bite. The simple addition of the torque arm also creates better "anti-squat" geometry and the the car is more level and planar under load and at WOT.

I have a number of customers running just the torque arm with standard Ford Racing suspension mods. The one comment I always get is that the car feels more controlled. One particular comment from a customer in South Carolina who has a long circular on ramp to the highway that he takes daily. Before the suspension mods there is a crack in the on ramp that would unsettle the car and really get the rear end loose. Now he just drives over it and doesn't feel a thing. He literally stays in the power. He's also got a Kenne Bell 2.8 and makes over 700 at the wheel.

The watts link only further compliments the torque arm by squaring the rear end and eliminating the panhard bar.

We've had customers with IRS suspensions remove the IRS, got to the Griggs system and their lap times are faster."

Van
Revan Racing

Since Van is mentioning the Griggs setup, it's obvious we're talking Mustangs. HOWEVER, the mention of the IRS pretty well pins it down to the 03/04 Cobra (SN95 chassis), which is NOT even close to the S197. Can you post a source for that quote? It seems that there are several inconsistencies in there, and some context would be good to see what we're really reading...

 

[sheizasosay]

http://www.fordgt500.com/forums/showthread.php?t=16569&page=2

 

[SoundGuyDave]

I invite other analyses, but it sure sounds like this is direct marketing-speak... The torque-arm by itself CANNOT affect lateral weight transfer in the rear, that's a function of the wheel rate (spring rate, plus bar rate, plus/minus bushing compliance, minus sidwall compliance). Thus, "corners flatter" is simply not possible only changing the torque-arm. That, plus the "removed their IRS" comment, and a few others, is enough to discount the entire statement. Not trying to fuel the fire, but that pretty much smacks of marketing, and not much else.

 

[Norm Peterson]

It appears that that fordgt500 post started with a kernel of accurate information and just kept extrapolating.

More anti-squat (which nobody is disputing) does provide greater rear tire grip as long as the car is still in the process of squatting toward it's steady-state position under however much forward acceleration. IOW, it's a temporary effect because the geometric effect occurs sooner than the compression of the rear springs.

Yes, that implies that more grip *might* be briefly available for lateral purposes, but it is not at all certain how much or even if any of it actually is. Don't forget that in order for anti-squat to give you any rearward load transfer there must be an increase in forward acceleration, which by friction ellipse theory means you clearly don't get to use all of however much added total grip for cornering. I won't say it's a flat-out wrong statement, but it is misleading to the extent that the reader is left to his (perhaps overactive) imagination what it'll be worth.

It is remotely possible that while cornering the anti-squat for the outboard tire differs from the anti-squat for the inboard tire, but except to note that this would affect both the 3-link and TA arrangements I think I'll leave it at that.



Whiskey - I'll try those numbers and maybe a few variations into my sheets and see.


Norm

 

[Whiskey11]

It appears that that fordgt500 post started with a kernel of accurate information and just kept extrapolating.

More anti-squat (which nobody is disputing) does provide greater rear tire grip as long as the car is still in the process of squatting toward it's steady-state position under however much forward acceleration. IOW, it's a temporary effect because the geometric effect occurs sooner than the compression of the rear springs.

Yes, that implies that more grip *might* be briefly available for lateral purposes, but it is not at all certain how much or even if any of it actually is. Don't forget that in order for anti-squat to give you any rearward load transfer there must be an increase in forward acceleration, which by friction ellipse theory means you clearly don't get to use all of however much added total grip for cornering. I won't say it's a flat-out wrong statement, but it is misleading to the extent that the reader is left to his (perhaps overactive) imagination what it'll be worth.

It is remotely possible that while cornering the anti-squat for the outboard tire differs from the anti-squat for the inboard tire, but except to note that this would affect both the 3-link and TA arrangements I think I'll leave it at that.



Whiskey - I'll try those numbers and maybe a few variations into my sheets and see.


Norm

Thanks Norm, I look forward to your results.

 

[hunterwiley]

We were racing this weekend again at Summit Point, and I spoke to Chris Cobetto specifically on his thoughts regarding the torque arm vs the 3 link rear. Surprisingly to me he said the biggest benefit he noted was in improved braking on the rear of the car.... less movement from the rear of the car under heavy braking.

A pretty cool pic from the start of the race....

 

[barbaro]

We were racing this weekend again at Summit Point, and I spoke to Chris Cobetto specifically on his thoughts regarding the torque arm vs the 3 link rear. Surprisingly to me he said the biggest benefit he noted was in improved braking on the rear of the car.... less movement from the rear of the car under heavy braking.

A pretty cool pic from the start of the race....

The torque arms effect on flat out race cars with coilover suspensions and slicks etc . . is certainly not going to be as noticeable as it is in a relatively lightly modded street car. But the observation is correct. Rear braking is greatly improved on a street vehicle. I found I could trail brake more confidently and high speed breaking (135 -70) where my rear end would get a little sketchy before, became controlled with the torque arm. I second everything Van's customer said as to vehicle control and Van's description of the Torque Arm's effect on the vehicle matches my experience exactly. And it is from the GT500 forum.

 

[Sky Render]

The torque arms effect on flat out race cars with coilover suspensions and slicks etc . . is certainly not going to be as noticeable as it is in a relatively lightly modded street car.

Really? Whiskey11, who just installed a torque arm on a "lightly-modded street car," apparently would beg to differ:

Driving impressions: If you are expecting some life changing mod, this aint it. To be perfectly honest it drives exactly the same in autocross. If I noticed any one feature about the TA setup it is that my car oversteers much easier and oversteers much more controlably than with the 3 link. I did some calculations based on actual measurements of the control arms and the 3 link at my height has about 18.60% AS vs the TA's 30.97%(assuming IC at about 44.5" longitudinally). That said, if throttle application came sooner it was by coincidence since the car felt very much the same. Squat was slightly reduced and I do think that the dive on braking was too.

Needless to say, is it worth the NVH increase and cost? Right now, not really. I suppose "every tenth counts" so I am sure it is "helping" in some way, but I cant say I know really where it is helping.