East Tennessee Region SCCA

The final piece for the GT500 will be here tomorrow for install and hopefully it will benefit the car as much as it is advertised to do. It is a cortex Torque Arm and should give more forward bite coming out of corner exit and on the tree at the pro solo launches. It will be a quick trial and see at the pro solo in Grenada to determine if it works as advertised. I should have it installed by the event at the smokies this Sunday for some testing and may have to change out the rear springs several times to see which one works best....

Torque Arm, burninating the peasants and countryside

Mine made a huge difference

Good luck!!

Installed but I have to torque all the bolts down and then put the tars back on it. Hope Sunday is a good test day before going to zmax the following weekend for more testing.

Teufelshund wrote: ↑Thu Mar 28, 2019 9:47 pm Mine made a huge difference

Your's is an older model than Jeff's. Do you have the sub-frame connectors too?

jcox07 wrote: ↑Fri Mar 29, 2019 4:52 pm Installed but I have to torque all the bolts down and then put the tars back on it. Hope Sunday is a good test day before going to zmax the following weekend for more testing.

So did it work?

My mechanic, who raced an S197 in NASA, doesn't think an S197 needs a torque arm. He also said that it would likely change the car balance towards more push so you would need a softer front bar and more roll stiffness in the rear to get back to where you were.

How much torque was the mechanics NASA car putting down at the wheels?

And if it made it go more towards a push, does that mean it had more rear grip will the arms?

Not sure who your mechanic is but the more power you make the more a torque arm helps and I really won't know how much it helps if any till I get it on a national size lot or when I get back from the pro in Grenada Miss. Smokies was not a lot to tell if it helped or not and it didn't seem pushy there but the speed is too slow on that lot to know anything.

dewittpayne wrote: ↑Mon Apr 01, 2019 6:07 pm

Teufelshund wrote: ↑Thu Mar 28, 2019 9:47 pm Mine made a huge difference

Your's is an older model than Jeff's. Do you have the sub-frame connectors too?

jcox07 wrote: ↑Fri Mar 29, 2019 4:52 pm Installed but I have to torque all the bolts down and then put the tars back on it. Hope Sunday is a good test day before going to zmax the following weekend for more testing.

So did it work?

My mechanic, who raced an S197 in NASA, doesn't think an S197 needs a torque arm.

^^ That's what Strano said about my SN95, but I did it anyway and it made a huge difference. I do have subframe connectors.

I assume that Dewitt's mechanic is Beau Dunnivant.

A torque arm definitely helps you power down better.

I assume that the reasoning behind not "needing" one for an S197 is because it is already an OEM 3 link. It'd still help you power down better. You might have to make changes to get the balance you want. Because you have more grip, which is what you want.

Not sure what Sam would recommend for an SN95. Just a panhard bar? He doesn't seem like he'd be a Watts link guy?

edit: I wish there was a viable place to be competitive in an SN95.

Oh Sam does like the watts link for sure!!

In general, sure. But for the SN95?

At least when I last paid attention, the Watts link was WAY more expensive and the panhard bar lowered the roll center, which is up in the trees for an fox/SN95.

steverife wrote: ↑Tue Apr 02, 2019 12:46 pm I assume that Dewitt's mechanic is Beau Dunnivant.

Correct. For SN95's he recommends a Panhard bar and a torque arm as well as the subframe connectors. The S197 frame is stiff enough that subframe connectors aren't needed.

At least when I last paid attention, the Watts link was WAY more expensive and the panhard bar lowered the roll center, which is up in the trees for an fox/SN95.

But do you want a low rear roll center for autocross? Moving the roll center up or down also changes the balance of the car. When you lower the rear roll center, you increase grip in the rear and lower it in the front, i.e. you make the car push more. A high roll center also makes weight transfer faster. With a chassis mounted Watts link and a high roll center, you get more movement of the roll center when cornering than you do with a Panhard bar and a low roll center, but at least the effect is the same when turning left or right, unlike a Panhard bar. But with stiff springs, there isn't that much movement. You can get Watts links with the propeller mounted on the diff, which makes the roll center move less than with a panhard bar. The Cortex diff mounted Watts link even has adjustable roll center height. It's even more expensive than the FAYS2 chassis mounted Watts link, though.

dewittpayne wrote: ↑Wed Apr 03, 2019 7:03 am But do you want a low rear roll center for autocross? Moving the roll center up or down also changes the balance of the car. When you lower the rear roll center, you increase grip in the rear and lower it in the front, i.e. you make the car push more.

I want a lower one than stock on a 79-04 Mustang. And I want to increase rear grip.