Cortex Torque Arm Racechrono Track Review

[Whiskey11]

Nice, can you comment on the beefiness of the plate that mounts to the rear diff? I have only seen it in pics thus far but it always seems to look rather thin and flexible. So far, are you pleased with the build quality of the parts you have pawed?

Thanks

This plate is quite thin, just going from memory it is either an 1/8" thick or 3/16". The part itself shares load with the two bolts you have to drill holes for on the ears on the front side of the diff housing and really I think this part is only there for ease of pinion angle setting initially before you drill the holes through. Filip was pretty adamant about drilling the top 5 holes on the diff cover out to 3/8" for more positive location of the diff cover but Im not really seeing the force being too high on the diff cover. I will do it anyway though.

As for the build quality, if you can judge a weld by the way it looks, these things are works of art. The welds are clean and beautiful and it looks like Filip and the crew worked pretty hard to get this thing light as the plate between the tubes on the arm itself is only stiched welded and isnt one long weld. It is also lighter than I expected, less than the assembled Fays2 Watts so less than 29lbs. The rear diff bracket is spray painted rather than powder coated. That is NOT normal, and was done AT MY REQUEST to expedite getting the arm to me before the Midwest Divisional Championship which starts tomorrow night.

So far I am impressed and I only hope the lower ground clearance at the axle doesnt cause issues getting out of my Townhouse farm. They have curb ends to each driveway and if I go out straight it scrapes the rocker stamped seam.

On Edit: I plan on taking a lot of photos but I wont be able to upload any from my DSLR until Monday since the cable company somehow didnt get my request to transfer service a week and a half ago... Cell phone pictures is all I have for the moment for immediate release.

 

[2013DIBGT]

This plate is quite thin, just going from memory it is either an 1/8" thick or 3/16". The part itself shares load with the two bolts you have to drill holes for on the ears on the front side of the diff housing and really I think this part is only there for ease of pinion angle setting initially before you drill the holes through. Filip was pretty adamant about drilling the top 5 holes on the diff cover out to 3/8" for more positive location of the diff cover but Im not really seeing the force being too high on the diff cover. I will do it anyway though.

I'm curious as to why the holes aren't just drilled out to the proper size from the get go. Is this because if one doesn't want to run the Torque Arm setup with the Watts link Diff the hole would otherwise be too large for the bolts that come standard with the Diff casing by itself?

Does drilling holes also then require tapping them with threads or does the bolts that come with the TA just pass thru the Diff housing (ie. tapered)into the rear pumpkin standard threads?

Thanks for the info

 

[barbaro]

Okay, let me try to explain this to you, again. I'll use small words, and break it down by paragraph...


1) The reason that it matters whether the Torque-arm is OE or not is to see if REPLACING one type of suspension with a T/A is showing benefits or not. Given Norm's posting of finishing positions and equipment, it would appear that the T/A is a contender. With his response, we can see that ALL the T/A cars were OE equipped with one, so that means that NOT a lot of people have made the swap and reached the upper levels...

2) The fact that an F-body, which is equipped with a Torque-arm, replaced it with an aftermarket fabricated 3-link, and is successful, would show that a T/A is NOT an automatic FTW part. This is called evidence, or data, that supports the argument AGAINST swapping from a 3-link to a T/A.

3) Hunter posted the video as a basis for supporting the Torque-arm as being superior to the 3-link, and I offered some thoughts about why that may not necessarily be the conclusion to draw from the video. In particular, driving style can have a BIG impact on how the rear behaves, as can desired chassis tuning to fit that style. Remember that as a general rule, "loose is fast."

4) This paragraph explains why I'm taking the position I am.

In the end, Barbaro, you may want to think a little bit, and post a little less... NOBODY here is going to make a huge suspension change to the car and drop a large amount of coin based on research evidence that consists of "Barbaro said it was 'bitchin!'" At least not without some hard data to back that up, of which you have provided exactly nothing.

I have said a lot more than that. And Who gives a toss about an F-Body? The benefits of the torque arm go beyond track times. Ride quality is greatly enhanced as the vertical movement of the chassis is greatly reduced. My reality is different from your reality. I have the torque arm watts link package. You do not. I have driven the setup you advocate. You have apparently not driven the setup I advocate. That puts you at a disadvantage and reliant upon making nonsensical comparisons about a piece you have no personal experience with.

I am one of many that believe this is a superior rear end set up to the traditional three link. I am in good company with Griggs and Cortex and feel very comfortable with their experience over anybody on this forum. All I ever did was give my personal experience which was at first ridiculed, then violently opposed and now is in the process of being accepted as self evident. That does not win me a popularity contest but I could care less. The truth is the truth.

 

[sheizasosay]

Making claims like your car "corners flatter" generally elicits a red flag when referring to a suspension piece that has no ability to influence that. The "supercharger of suspension" and "11 on a 1-10 scale" gets you little credit regardless if you have driven every configuration possible regardless of who you decide to stand behind in California.

In general, Filip gets a lot of respect aswell as Griggs, Agent 47 and Maximum Motorsports. But I'm a consumer and so is 99.9% of the members of this forum. The shit your saying doesn't add up. Sorry. You talk all about the truth, but seen to resist the process of weeding through all the claims while you default to who you would rather line up behind. In fact, claims you make, not even the manufacturer makes or any manufacturer that has ever made a torque arm claims what you do in full. So what you have done is piqued curiosity. You have done well for Cortex.

In the end, Whiskey's review will be positive of the TA and will shed a positive light for the TA because it will be an "aftermarket vs OEM comparison";it will have only replaced a stock UCA and not an aftermarket UCA/Mount dialed in for more AS. This will probably be a big "plus" for Whiskey in autocross, but will still leave a hole in regards to a conclusion for a road course.

And after Whiskey makes his post, you'll probably say something in regards to "I told you so" or "I rest my case" and it won't mean The End for anybody with a hair of suspension knowledge. And I do mean a hair.

 

[SoundGuyDave]

I have said a lot more than that.

Yeah, you did... like posting somebody else's comments about a Hellion turbo kit. To echo your earlier question, "So What?"

And Who gives a toss about an F-Body?

The only reason that I even brought that up was because the F-Body has a Torque-arm as OE, and a nationally competitive American Iron car has profited from ditching the TA for a 3-link. Just a data point, that at least shows that maybe, perhaps, the TA isn't the holy grail of suspension technology...

The benefits of the torque arm go beyond track times. Ride quality is greatly enhanced as the vertical movement of the chassis is greatly reduced.

Really... do tell... "Ride quality" is generally accepted to be the vehicles ability to isolate the chassis from road irregularities, like bumps. The major players in that department are damping, spring rate, and bushing compliance (isolation). Why do you think Ford went with that god-awful hydro bushing on the front LCA? Because it was cheaper? Hardly. Vertical chassis movement on hard acceleration does factor in A/S%, and yes, the torque arm MAY have a higher A/S%, but that is still largely a function of the rear LCA mount locations. In other conditions, vertical chassis movement is strictly a function of wheel rate, which includes spring rate and bushing compliance. IF ALL THINGS REMAIN THE SAME excepting the swap from a 3rd link to a Torque-arm, wheel rate will not change, and thus neither will vertical chassis movement.

My reality is different from your reality.

Obviously.

I have the torque arm watts link package. You do not. I have driven the setup you advocate.

I will grant you that. I do not personally own a T/A plus Watts car. So you're saying that you've driven a COMPLETELY Heim-equipped S197? No rubber diff bushing, no poly, rubber or Delrin in any of the three rear arms or the Panhard bar?

You have apparently not driven the setup I advocate. That puts you at a disadvantage and reliant upon making nonsensical comparisons about a piece you have no personal experience with.

You are correct in that I have NOT driven a T/A plus Watts S197. I HAVE driven Watts cars, and I HAVE driven T/A cars, so I feel that I do have a leg to stand on.

I am one of many that believe this is a superior rear end set up to the traditional three link. I am in good company with Griggs and Cortex and feel very comfortable with their experience over anybody on this forum. All I ever did was give my personal experience which was at first ridiculed, then violently opposed and now is in the process of being accepted as self evident. That does not win me a popularity contest but I could care less. The truth is the truth.

Okay... First, your "personal experience" was given only in terms of platitudes and hyperbole, and it has since become obvious that you have little, if any, understanding of the theory behind suspension operation. You weren't ridiculed and/or violently opposed for your opinion, it was because you presented it in such a fashion that flies in the face of everything we KNOW (not guess or assume) about suspension operation. Your claim earlier in your post about the TA reducing suspension motion is a case in point. Then, when you were called on the (essentially) outlandish claims you made, you got exceedingly defensive, as if you couldn't BELIEVE that we unwashed masses would dare to refute your "bitchin" descriptions as gospel.

Here's what I think actually happened... You bought a stock Mustang, and drove it like an ass-hat. You assumed that your skill as a driver was self-evident (like Rain-Man's "I'm an excellent driver" schtick), so you threw a pile of parts at the car. You changed the PHB out for a Watts, you changed the 3rd link out for a TA, and while you were at it changed dampers, springs, relocated suspension mounting points, changed the lower control arm bushing material, etc. You were then incredibly pleased with the results, and proclaimed it "bitchin." I'm actually pleased for you, no sarcasm. It sounds like you have a nicely put together rear suspension. What you can't comment on, however, is how any one of these pieces IN ISOLATION has affected the behavior of the entire package. Your comment about ride quality points at dampers and springs. Your comment about vertical chassis movement points at springs and/or LCA relocation. You haven't offered any metric for pre/post comparison at all, while insisting that your opinion is the only one that is valid, or "true," and generally acting like a messiah that is being refuted. THAT is what we're all taking exception to.

In the end, a torque arm does EXACTLY the same job as a 3rd link, albeit in a completely different way. I will grant that the Watts is probably a superior solution for lateral location, but I will still argue that it truly shines in certain situations, and less effective in others, where the cost/benefit may not be so clear cut. Are they night and day different from a stock 3-link/PHB? You bet they are. Compared to a completely Heim-equipped car, though, I think no so night and day. When you start tightening down the suspension setups, moving more towards "race" and further from "street," the differences just might be vanishingly small.

 

[Norm Peterson]

. . . And Who gives a toss about an F-Body?

You should. You should know this already, but if you don't you wouldn't listen to any explanation anyway.

Ride quality is greatly enhanced as the vertical movement of the chassis is greatly reduced.

Unless you have your own reality for what constitutes ride quality that differs from the rest of the world, that statement make no sense whatsoever (and to some extent your statement can be exactly wrong).

You still don't understand the concept of 'pitch', so I'm probably wasting keystrokes here trying to tell you that similar pitch behavior to a torque arm suspension can be obtained from a 3-link suspension.

At this juncture the torque arm is class-legal in a few places where a modified OE 3-link approach is not. Understand that in such cases, the torque arm becomes relatively more appealing because of that artificial constraint. This isn't a pass/fail, right choice/wrong choice situation yet.

I <snip> believe this is a superior rear end set up to the traditional three link.

It is quite possible that a TA handles big power on corner exit better than the Mustang's OE 3-link, and I think I mentioned this or something essentially similar way back toward the beginning.

What neither of us knows is whether a TA would still be better than modified 3-link geometry on that same car. All we do know is that (for now, at least) the TA involves a lot less mechanical work for the individual end-user and no design/re-design work at all.

I <snip> feel very comfortable with their experience over anybody on this forum.

Of course you are. You aren't trying to convince them of anything and it's not them trying to tell you that "miraculously seeing the light" doesn't exactly qualify as tech.

All I ever did was give my personal experience which was at first ridiculed, then violently opposed and now is in the process of being accepted as self evident. That does not win me a popularity contest but I could care less. The truth is the truth.

It's not what you say, it's how you say it. Get over this persecution complex and there might be a few less red flags running up the flagpole every time your user name shows up on a notice of reply to a S197forum topic. You've heard of Pavlov's experiment?


Norm

 

[Whiskey11]

I'm curious as to why the holes aren't just drilled out to the proper size from the get go. Is this because if one doesn't want to run the Torque Arm setup with the Watts link Diff the hole would otherwise be too large for the bolts that come standard with the Diff casing by itself?

Does drilling holes also then require tapping them with threads or does the bolts that come with the TA just pass thru the Diff housing (ie. tapered)into the rear pumpkin standard threads?

Thanks for the info

The holes are factory Ford holes for a specific bolt doameter but there is a decent amount of play compared to the provided bolts. I want to point this out again.because it bears repeating: "This is an abnormal setup. Filip only recommends two diff covers for his torque arm but was willing to work with me on this one. Those to covers are the one he sells on his site which looks like the FRPP load bearing cover and his watts link.cover. Both stick out too far to be used with the Fays2 watts link so this is a compromise. His deciscion to go a head was based on the.notion that this car will probably never see more than 350 rwhp/rwtrq.

To answer your question, the bolts are shoulder bolts with a narrower threaded section than the shoulder so there is.no tapping. Until I get everything installed I wont really know how much, if any, need drilling out.

 

[Norm Peterson]

In the end, a torque arm does EXACTLY the same job as a 3rd link, albeit in a completely different way.

I have to grin at that, Dave. The easiest way I found to model torque arm behavior as a function of ride height was to start from a 3-link model and construct a virtual "upper link" at the chassis end of the torque arm. The torque arm itself? Just a huge axle-side bracket for that virtual link.

I wonder if he'll realize the irony . . .


Norm

 

[Norm Peterson]

To answer your question, the bolts are shoulder bolts with a narrower threaded section than the shoulder so there is.no tapping. Until I get everything installed I wont really know how much, if any, need drilling out.

I'd really like to see the diff cover dowelled in place for either the Cortex-style torque arm bracket or any diff-mounted Watts link. Ford's OE diff cover bolt torque is only 33 ft-lbs or so, which can develop only so much friction. So you need a shear connection, which I think I'm reading that Filip's solution manages to accomplish here. However, absent any external constraints I'd prefer to keep the dowels separate from the 10 cover bolts if at all possible, more like what you see at the bellhousing to block connection. Whether that would be SCCA ST or SP legal is a whole other question.

I'll put a whole lot more faith in your experience and evaluation, and hope it's all positive without too many minor "teething pains".


Norm

 

[Whiskey11]

I'd really like to see the diff cover dowelled in place for either the Cortex-style torque arm bracket or any diff-mounted Watts link. Ford's OE diff cover bolt torque is only 33 ft-lbs or so, which can develop only so much friction. So you need a shear connection, which I think I'm reading that Filip's solution manages to accomplish here. However, absent any external constraints I'd prefer to keep the dowels separate from the 10 cover bolts if at all possible, more like what you see at the bellhousing to block connection. Whether that would be SCCA ST or SP legal is a whole other question.

I'll put a whole lot more faith in your experience and evaluation, and hope it's all positive without too many minor "teething pains".


Norm

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.

 

[2013DIBGT]

Hrrm interesting, did you notice if the rear pumpkin changed height at all after removing the UCA? Wondering if by not having the UCA now if the ass end has more upward movement over bumps..etc possibly causing the rear springs to bang around on the spring seat area.

Then again, it could be the beer talking to me causing spewed nonsense. Good luck tracking it down.

 

[Whiskey11]

Hrrm interesting, did you notice if the rear pumpkin changed height at all after removing the UCA? Wondering if by not having the UCA now if the ass end has more upward movement over bumps..etc possibly causing the rear springs to bang around on the spring seat area.

Then again, it could be the beer talking to me causing spewed nonsense. Good luck tracking it down.

Could be, I have always thought the springs on the GC kit are too short for the height adjustment and at full droop they are LOOSE but Im not sure a tender setup will work on a live axle will it?

That said it almost sounds like something sliding on a loose bolt. I have to retorque everything anyway. That said shes waaay too hot to work under right now. I did find one of the jam nuts on the Fays2 loose so it got torqued down good.

 

[csamsh]

Could be, I have always thought the springs on the GC kit are too short for the height adjustment and at full droop they are LOOSE but Im not sure a tender setup will work on a live axle will it?

That said it almost sounds like something sliding on a loose bolt. I have to retorque everything anyway. That said shes waaay too hot to work under right now. I did find one of the jam nuts on the Fays2 loose so it got torqued down good.

How short are your springs? I have a very different rear end setup from you, but mine are 8" springs, with the weight jackers probably at 1.5-2" higher than the axle seat.

 

[Whiskey11]

How short are your springs? I have a very different rear end setup from you, but mine are 8" springs, with the weight jackers probably at 1.5-2" higher than the axle seat.

I believe they are 10" but I dont remember off the.top of my head. I would have to.go look again under the car.

 

[DTL]

Regarding the cover dowels: My Cortex watts cover came with 2 hollow sleeve type dowels and a bit to properly oversize a portion of 2 of the diff cover holes. I haven't had any issues with the cover trying to come loose or move.

 

[Whiskey11]

I thought I should update after day 1 of the midwest divisional:

No idea what the clunk is but I am going to rebuild that side ofthe TA mount either tonight or tomorrow night or Monday or Tuesday... ok, sometime this week.

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.

 

[barbaro]

I thought I should update after day 1 of the midwest divisional:

No idea what the clunk is but I am going to rebuild that side ofthe TA mount either tonight or tomorrow night or Monday or Tuesday... ok, sometime this week.

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.

It does help to have the Watts link and the adjustable heim jointed lower control arms allowing for substantiallly more articulation of the rear suspension. The rear grip package you may find more to your liking but unfortunately not autocross legal. I did not notice the NVH you are talking about. More controllable oversteer is a much bigger advantage at the track than it is in autocross. Reduced squat and nosedive can't be a bad thing.

 

[barbaro]

You should. You should know this already, but if you don't you wouldn't listen to any explanation anyway.



Unless you have your own reality for what constitutes ride quality that differs from the rest of the world, that statement make no sense whatsoever (and to some extent your statement can be exactly wrong).

You still don't understand the concept of 'pitch', so I'm probably wasting keystrokes here trying to tell you that similar pitch behavior to a torque arm suspension can be obtained from a 3-link suspension.

At this juncture the torque arm is class-legal in a few places where a modified OE 3-link approach is not. Understand that in such cases, the torque arm becomes relatively more appealing because of that artificial constraint. This isn't a pass/fail, right choice/wrong choice situation yet.


It is quite possible that a TA handles big power on corner exit better than the Mustang's OE 3-link, and I think I mentioned this or something essentially similar way back toward the beginning.

What neither of us knows is whether a TA would still be better than modified 3-link geometry on that same car. All we do know is that (for now, at least) the TA involves a lot less mechanical work for the individual end-user and no design/re-design work at all.



Of course you are. You aren't trying to convince them of anything and it's not them trying to tell you that "miraculously seeing the light" doesn't exactly qualify as tech.



It's not what you say, it's how you say it. Get over this persecution complex and there might be a few less red flags running up the flagpole every time your user name shows up on a notice of reply to a S197forum topic. You've heard of Pavlov's experiment?


Norm

Norm, how do you get any work done? Your numerous and predictably detailed responses to everyone of my posts actually elevates my profile beyond what is justified. You doth protest too much. 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.

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

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.

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

The real people who know aren't on here and other forums accumulating thousands of posts as you have. That is characteristic of someone with Aspergers and too much time on their hands. 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.

 

[sheizasosay]

Except for the fact that I drove with the Watts link for months before I ever put the torque arm on. So I had a chance to evaluate the Watts link individually. Watts link by itself is a 4 on a scale of 1-10. Add Torque arm and 11 on a 10 scale. I know there are skeptics and naysayers...

..... Bottom line is that while I respect everyone's opinion, Jesus could come down off the cross and tell me the torque arm is fools gold and I would laugh in his face. Again, I will repeat what I have said elsewhere. A torque arms is the single most transformative suspension mod you can do to your car. It is the equivalent of putting a supercharger on your suspension. If you don't believe me now, you will the second you drive one and I do mean one second because that is about how long it will take for you to notice the difference.

Is it?

 

[Whiskey11]

Is it?

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.