SS #670 Modifications:
Adjustable torque arm

[LG Motorsports]

I believe there are two main reasons to use an aftermarket torque arm. First, a strong design will greatly reduce flex the OEM version exhibits. Second, you can reduce compliance by switching from rubber OEM bushings to urethane or better yet using spherical rod ends.

After exploring some other options (see the details further down on the current page), I settled on the LG Motorsports G2 heavy duty torque arm.

G2 torque arm Installed

The front attachment is on the transmission and uses a modified OEM mount with a greaseable aircraft spherical bearing welded to it. The arm is mig welded using 0.095 wall heat treated square steel tubing. The arm weighs 15 lbs, about the same as stock.

Installation notes

Summary

The G2 heavy duty torque arm made a subtle but important change in the handling of SS #670. It's expensive and somewhat exotic but like subframe connectors, its effects are important but quickly taken for granted. I like it!


[Spohn Performance]

My Previous Setup

The first torque arm I tried was a Spohn. As expected, it transmitted more noise into the cockpit but it also had a slight clunking sound when making a transition from forward to reverse, reverse to forward or hard braking to launching. It was also the tube-and-rod slider design which broke after about two years of daily driver duty.

Next I tried Spohn's updated design featuring a spherical rod end and shackles front assembly. This one certainly didn't look fragile but unfortunately it also made clunking sounds, sometimes the result of getting out of the throttle. After about six months, I reinstalled the factory torque arm to confirm the Spohn was the cause of the noise.

[Spohn torque arm]

The Spohn arm is about twice as heavy as the stock version (32 vs. 15 lbs) but it looks like it would be bulletproof in a drag strip car. It's also adjustable, a feature I don't need but is desirable for drag racing.

While the factory torque arm attaches to the transmission, Steve Spohn's is one of several aftermarket designs that attaches to the floorboard. A nice feature of the Spohn torque arm is the shackle assembly that connects the arm to the cross member assembly. It allows front to rear movement of the differential.

The one I used was black with the NHRA compliant front driveshaft safety loop and the chromemoly spherical rod end. I also requested that my cross member be made straight for extra ground clearance. (The normal version is curved and only hangs low where it needs to; where the exhaust pipe is.)

The arm is stout, the welds are pretty and the powder coating is thick. I hear that it takes six hours to fabricate one! The shackles assembly and rod end have grease fittings.

The torque arm cross member did an excellent job of tying my of my Kenny Brown subframe connectors together.

Installation notes

Fasteners

This chart reminds me which tools I need to work on the torque arm:

Description Specification Tool Count
Floor pan bolts M8 X 1.25 X 30mm 13mm 4
Lower shackle 3/4-10 X 3" 1-1/8" 1
Upper shackle 5/8-11 X 3" 15/16" 1
Rear U-Joint ? 11mm 4
Solid end 5/8-11 X 2-½" 15/16" 2
Differential housing bolts 9/16-12 X 8" 15/16" 2
Differential housing bolts (stock) M16 X 2 X 180mm 21mm 2


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[SS #670 The Super Sport Owners Association] [SS #670 Miscellaneous] [SS #670 EMail Craig]
[SS #670 Mods: Sway bars] [SS #670 Mods: Shocks and struts] [SS #670 Mods: Springs] [SS #670 Mods: Panhard bar] [SS #670 Mods: Lower control arms] [SS #670 Mods: Subframe connectors] [SS #670 Mods: Adjustable torque arm]
[SS #670 Mods: Differential] [SS #670 Mods: ZR1 wheels] [SS #670 Mods: Shock tower brace] [SS #670 Mods: Brakes] [SS #670 Mods: Hurst billet plus shifter] [SS #670 Mods: Heel/Toe throttle extension plate] [SS #670 Mods: Driveshaft safety loop]
[SS #670 Mods: Radiator] [SS #670 Mods: Oil cooler]
[SS #670 Mods: Differential vent tube] [SS #670 Mods: Shiftlight] [SS #670 Mods: Airbox lid] [SS #670 Mods: Polyurethane bushings]
[SS #670 Mods: Auto Meter gauge pod] [SS #670 Mods: Disable CAGS] [SS #670 Mods: Disable daytime running lights]

[SS #670 Mods: EFILive] [SS #670 Mods: LS1_Edit]
[SS #670 Mods: Battery] [SS #670 Mods: Valentine One remote display] [SS #670 Mods: Headlights] [SS #670 Mods: iPod integration] [SS #670 Mods: LEDs] [SS #670 Mods: Cellular phone] [SS #670 Mods: Zaino Bros' show car polish]

Copyright © 2001, 2002, 2003, 2004, 2005, 2006, 2007
Craig Leres