Cortex Torque Arm Racechrono Track Review

[Sky Render]

At least 2 companies sell weight jacks for the rear that allow you to run 2.5" coil over springs on the axle in the stock location and adjust ride height and corner weight.

Which companies?

 

[DTL]

Ground Control and Vorshlag. I think Maximum Motorsport may as well.

Regarding the motion ratio changes; As with anything else, there's a tradeoff to be made. I chose to make room for more wheel/tire. I'm a follower of the "tire, tire, tire" philosophy, as are many others. If you're class-limited to a wheel and tire size that leaves room for coilovers in the rear, then by all means, go that route.

 

[barbaro]

Hello, I have been following this thread with interest because I am about 86.7757575% sure that I will be installing a suspension kit that also includes a Torque Arm/Watts Link combo like the Cortex setup but in my case it will most likely be the Griggs GR40SS kit.

I'm curious to hear what the general consensus is on why these rear end packages offered by Cortex & Griggs focus in on swapping out the rear spring/shock combo for a coilover?

I see the original poster has chosen to not use a rear coilover setup on his car so I guess its safe to assume that a coilover is not a requirement when using a Torque Arm.

My original thought for the use of the coilover was that it is mainly because they offer a means to corner balancing the car? Besides corner balancing, what are the short falls, if any, of using a standard rear spring/shock combo with these kits?

Another question to the OP, did you purchase the "Quiet/Street" components in your kit? Do you run or intend to run slicks at the drag at any point? If so, do you have any concerns with having a urethane bushing in the rear control arm verse a full Heim setup?

Thanks for the interesting post on this topic and any additional info you can provide.

Torque arms on sn-95's required stiffer springs or coilovers. My understanding was because the spring sat on the lower control arms as opposed to the axle on our cars. A torque arm and weak spring on an sn95 led to a wobbly body roll on those cars. Not a problem on our cars. I asked Filip specifically about this issue and he said that high spring rate coilovers were not necessary and that stock boss 302 spring rates were just fine and even advisable for a nice ride on the S197 chassis. Of course coilovers give you that next level of performance but my Koni Yellows ans Boss or Steeda Sport springs are good enough for my ability level.

Although I am strongly considering going to a coilover setup. But even with a soft spring setup there will be the telltale metal on metal sound with coilovers. I get a bit of that now with the heim jointed lower control arms on the axle end. Going full heim jointed is not advisable for frequent street use. I have been specifically advised against it unless I am going for a full race set up, which I am not. But the effect of the watts link/torque arm/heim jointed on one end lower control arms is so drastic on rear end grip, trust and believe I have no concerns. Would full heim be better? Whatever performance advantage it gave me would not be worth the nvh on the street. Especially when you consider what a drastic upgrade it already is over the stock set up. But that is me. Others I am sure have a different opinion.

 

[Whiskey11]

Torque arms on sn-95's required stiffer springs or coilovers. My understanding was because the spring sat on the lower control arms as opposed to the axle on our cars. A torque arm and weak spring on an sn95 led to a wobbly body roll on those cars. Not a problem on our cars. I asked Filip specifically about this issue and he said that high spring rate coilovers were not necessary and that stock boss 302 spring rates were just fine and even advisable for a nice ride on the S197 chassis. Of course coilovers give you that next level of performance but my Koni Yellows ans Boss or Steeda Sport springs are good enough for my ability level.

Although I am strongly considering going to a coilover setup. But even with a soft spring setup there will be the telltale metal on metal sound with coilovers. I get a bit of that now with the heim jointed lower control arms on the axle end. Going full heim jointed is not advisable for frequent street use. I have been specifically advised against it unless I am going for a full race set up, which I am not. But the effect of the watts link/torque arm/heim jointed on one end lower control arms is so drastic on rear end grip, trust and believe I have no concerns. Would full heim be better? Whatever performance advantage it gave me would not be worth the nvh on the street. Especially when you consider what a drastic upgrade it already is over the stock set up. But that is me. Others I am sure have a different opinion.

The Fox/SN95 chassis has bind built into the 4 link setup that adds a noticeable amount of "spring" rate during body roll. Removing the two upper control arms removes that bind from the equation and leaves only the springs and swaybar to factor in for wheel rate. I don't remember the actual numbers but it was significant enough that a torque arm caused a ton of extra body roll. The S197 chassis doesn't have nearly as much bind in the 3 link + PHB/Watts link configuration to add that much spring rate to be noticeable so the effect is less so.

I really can't wait for me to close on the house so I can do the Torsen T2R/Torque Arm setup. I'm interested to see how it behaves in an autocross environment and if it is true that it makes the car easier to drive at the limit then hopefully that decreases times!

 

[Ivan 5.0]

Going full heim jointed is not advisable for frequent street use... Whatever performance advantage it gave me would not be worth the nvh on the street. Especially when you consider what a drastic upgrade it already is over the stock set up. But that is me. Others I am sure have a different opinion.

Just my two cents - thought I'd throw this out there for folks that are considering poly vs spherical ends. I have MM lower control arms and an MM panhard rod with spherical bearings on both ends. The noise increased a bit - but all I hear is a whir coming from the rear. It's slightly audible over my exhaust. For me personally, the NVH is not bad and I got completely used to it after a week of driving. Its a Mustang - not a friggin E-Class Mercedes

 

[Norm Peterson]

Fox/SN95 UCA bind in roll is probably one of the small things.

The big one is that when you swap from the Fox/SN95/GM intermediate style of triangulated 4-link to a TA with a PHB you're dropping the rear roll center by several inches . . . from something like 17" down to around 12", which is a lot of added roll moment to have to make up for with the rear springs and/or rear bar to re-balance the car.


For the motion ratio part, the OE spring seats in the S197 could be considered to have a different motion ratio in roll than in two wheel bump mode, which means that the damping effect of the shocks probably cannot perfectly suit both situations simultaneously. I have no idea how much that might be leaving on the table.


Norm

 

[barbaro]

So who has gotten a torque arm?

 

[55R2014]

So who has gotten a torque arm?

Me. I got mine about 3 weeks ago. I love it! The car feels noticeably different and and sticks well under acceleration. I noticed reduced squat on launch and reduced nose dive on braking. I'm still on stock tires. Now I need more motor….can I borrow yours…lol!

 

[Whiskey11]

So who has gotten a torque arm?

Waiting until I sign on the house on August 5th before I buy mine.

 

[Ivan 5.0]

Me. I got mine about 3 weeks ago.

Did you go from a factory or aftermarket third link?

 

[55R2014]

Did you go from a factory or aftermarket third link?

I went from the factory Track Pack suspension. I did it in two steps. I put 3000 miles on the stock suspension first then did the coil overs, watts link, and lower control arms. Did another 2000 miles before adding the torque arm.

 

[sheizasosay]

I went from the factory Track Pack suspension. I did it in two steps. I put 3000 miles on the stock suspension first then did the coil overs, watts link, and lower control arms. Did another 2000 miles before adding the torque arm.

Do you share Barbaro's thoughts that out of all the suspemsion pieces the torque arm was without a doubt the greatest handling mod for the s197known to the universe (and whatever is on the other side of a black hole)?

 

[55R2014]

Do you share Barbaro's thoughts that out of all the suspemsion pieces the torque arm was without a doubt the greatest handling mod for the s197known to the universe (and whatever is on the other side of a black hole)?

I would have to say no. I do not have his experience to make that level of assessment or claims. However, I do agree with Barbaro's thoughts that it definitely does add to the handling of the car especially in acceleration and breaking. That is from my extremely limited street experience. Barbaro has had his car on the track, I have not. He has stated he has a lot of experience with S197 chassis and different setups.

I will say that after driving my car with this setup with the factory wheels and tires, I would not feel nearly as comfortable or confident in its handling ability than if it had the stock Track Pack suspension.

 

[barbaro]

I went from the factory Track Pack suspension. I did it in two steps. I put 3000 miles on the stock suspension first then did the coil overs, watts link, and lower control arms. Did another 2000 miles before adding the torque arm.

I think that because your Cortex handling setup was 3/4 done before the torque arm, your improvement while noticeable was not as dramatic as it was in my case where I had the BMR non adjustable non heim jointed control arms and Koni Yellows on Boss springs. Filip's package without the torque arm is plenty good by itself. In your case, I think the Torque arm was the final piece rather than the central piece as it was in mine. I am looking forward to some time this month putting on the same Cortex coilover package that you have and I expect another bump up in handling. Question though, did you experience any increase in suspension noise with the Coilovers. And BTW Mt car is in the June edition of "Mustang Performance" put out by Mustang 5.0 and not MM&FF, sorry to mislead, my mistake. "Mustang performance" is a yearly edition put out by 5.0 featuring privately owned cars. How do you like your setup overall. I think it is the best integrated suspension setup currently available. My judgment will be more definitive once I put on the coilovers though.

 

[sheizasosay]

I think that because your Cortex handling setup was 3/4 done before the torque arm, your improvement while noticeable was not as dramatic as it was in my case where I had the BMR non adjustable non heim jointed control arms.

Those (urethane) bushings in the BMR LCA's that I believe you had are "worse" than stock for cornering. Some interesting info to consider in regards to bushing bind adding to wheel rate: Standard 2 piece setup using only 85 durometer bushings:


5 degrees of total rotation = 124.7 foot/pounds of torque

7.5 degrees of total rotation = 156.4 foot/pounds of torque

10 degrees of total rotation = not measurable with fixture. The 1/2" grade 8 bolt twisted in half at 9.2 degrees which was 210 foot/pounds of torque.

Copied from J&M's web as the source cited above.

 

[Chris borzi]

I had installed the bmr k member and a arms and had some suspension noise coming from the front struts after that. Ordered the cortex coil overs and I have no noise at all. It has been my best purchase.

 

[55R2014]

I think that because your Cortex handling setup was 3/4 done before the torque arm, your improvement while noticeable was not as dramatic as it was in my case where I had the BMR non adjustable non heim jointed control arms and Koni Yellows on Boss springs. Filip's package without the torque arm is plenty good by itself. In your case, I think the Torque arm was the final piece rather than the central piece as it was in mine. I am looking forward to some time this month putting on the same Cortex coilover package that you have and I expect another bump up in handling. Question though, did you experience any increase in suspension noise with the Coilovers. And BTW Mt car is in the June edition of "Mustang Performance" put out by Mustang 5.0 and not MM&FF, sorry to mislead, my mistake. "Mustang performance" is a yearly edition put out by 5.0 featuring privately owned cars. How do you like your setup overall. I think it is the best integrated suspension setup currently available. My ju dgment will be more definitive once I put on the coilovers though.

I was able to find the article in the June edition of "Mustang Performance". Congratulations, you have a beautiful car.

You are correct, the torque arm was the final piece of the package. At Filip's recommendation, I put some good lies on the car before the suspension upgrade so I could appreciate the difference of the new suspension. Then he suggested I wait on the torque arm for the same reason. I'm glad I followed his recommendations.

I love the way my car drives now. It rides very smooth and comfortable. The backend side-to-side drama and bouncy-ness are gone. I have not experienced any increase in suspension noise with the Coilovers. I am running the lighter spring rates for street with the poly ends on the chassis locations. The ride is firm but not harsh. Despite being lowered two inches on all four corners, the car does not bottom out over heavy dips and bumps.

 

[55R2014]

I had installed the bmr k member and a arms and had some suspension noise coming from the front struts after that. Ordered the cortex coil overs and I have no noise at all. It has been my best purchase.

I have no noise coming from my suspension, front or rear. The rear coilover mounts a secure and solid.

 

[Sky Render]

http://www.s197forum.com/forum/showpost.php?p=1821903&postcount=326

 

[55R2014]

Interesting read. Some good information and history.