FAQs & Tech Tips

MM News

MRT Exhaust! MM now offers premium MRT cat-back exhaust systems for 1996-2004 Mustangs.

New! for Street & Strip Mustangs! Big-bore rear wheel cylinders for 1979-1993 Mustang with 9" drum brakes. Improves braking when running big rear tires and front skinnies, and/or different OEM front brakes.

New! Swapping a Coyote into a Fox Mustang? MM's Hydroboost Conversion Kits allow easy installation of a 1996-2004 Mustang Hydroboost power brake assist unit into a 1979-1993 Mustang.

New! Swapping an IRS into your Fox Mustang? MM makes it easier with a brake line kit made just for this conversion. Bolts-in, with no cutting or flaring of brake lines. Designed to fit standard IRS brake hoses.

New! MM's billet aluminum Pedal Box Spacer for Fox Mustangs. Replace the breakage-prone OEM plastic spacer when converting to manual brakes or Hydroboost.

Canadians! Please read the latest about ordering from Canada/shipping to Canada.

/DRIVE
We've posted the parts list and link to the video of MM's Mustang in /DRIVE Tuner car Shootout

Maximum Motorsports Torque-arm FAQs

Don't forget to read this list of questions that must be answered before purchasing a Torque-arm. Most of the ordering related questions are also discussed in these FAQs below.

How do I get more traction?
Install a Maximum Motorsports Torque-arm. It is the key to maximizing rear grip for a solid-axle equipped Mustang.

What will the MM Torque-arm do for me?

  • It will increase straight-line traction.
  • It will provide more rear grip during cornering.
  • It will improve corner-exit acceleration.
  • It will provide superb control and predictability.
  • It will increase wet weather traction.
  • It will improve ride quality.

What is a Torque-arm?
It is a long suspension arm that attaches between the rear axle housing and the chassis.

Is a Torque-arm okay for street driving, or is it just for drag racing or road racing?
The MM Torque-arm is great for all three situations. Increased rear grip helps in every type of driving; would you ever complain about having too much traction?

What's wrong with the stock Mustang rear suspension?

  • All 1979-2004 solid-axle equipped Mustangs have the same 4-link rear suspension first designed for the 1978 Ford Fairmont. It has significant limitations in performance applications.
  • The Mustang's rear suspension design forces the upper control arms to perform two jobs at once. They control the side-to-side position of the axle housing, while also preventing axle-housing rotation during acceleration and braking.
  • The Mustang upper control arm design fails to perform either job well. This design causes binding of the rear suspension that not only leads to poor handling and traction problems, but also damages the upper control arm mounts on the chassis.

How does the MM Torque-arm improve traction and handling?

  • The complete MM Torque-arm Suspension System replaces the troublesome upper control arms with the MM Torque-arm and Panhard Bar. This separates the two functions once performed by the upper arms. The Torque Arm controls axle housing rotation during acceleration and braking, and the Panhard Bar controls the side-to-side position of the axle housing. With each part dedicated to a specific job, each can perform its function without compromise, greatly improving the performance of your Mustang.
  • The MM Torque-arm plants the rear tires much better during acceleration than the stock four-link design, and the Panhard bar locates the axle much more precisely. Your Mustang's overall performance will be greatly improved, with much better acceleration out of corners, along with improved handling, stability, better straight-line launching ability, and increased predictability.

Which Torque-arm is right for me?

  • There are two versions of the MM Torque-arm: Standard-Duty, and Heavy-Duty. Both provide the same performance improvements for your Mustang, but each is rated for a different level of engine torque.
  • Which Torque-arm your Mustang needs depends on the transmission's first gear ratio, the rear gear ratio, the amount of rear wheel torque, and how you drive it. Keep reading to see how to choose between the two Torque-arms.

How are the Torque-arms rated?
We determined the limits of each torque-arm by destructively testing them. Each torque-arm was then rated for the most difficult scenario possible: a high-revving-sidestep-and-dump-the-clutch launch, with no clutch slippage, on sticky drag tires that grip the pavement instead of burning rubber. That's the type of launch that will send the front tires skyward. If you don't mount up sticky drag tires and drive your Mustang like that, then the maximum rear wheel torque ratings listed may be disregarded for your situation.

How do I choose between the two Torque-arms?

  1. Find your transmission's first gear ratio (or your transmission model) in the heading of one of the three Torque-arm Rating Tables below. The first gear ratio determines which table applies to your Mustang.
  2. Find your car's rear gear ratio in the far left column of that table.
  3. On the row with your rear gear ratio, look to the right. The next two columns have the rear wheel torque ratings for each Torque-arm. The first is the maximum rear wheel torque rating for the Standard-Duty Torque-arm. The second is the maximum rear wheel torque rating for the Heavy-Duty Torque-arm. These torque ratings refer to the peak rear wheel torque as measured on a Dynojet chassis dyno.
  4. Select the Torque-arm that has a rear wheel torque rating that is higher than the peak rear wheel torque that your Mustang produces, as measured on a Dynojet chassis dyno.
  5. Note: Take into consideration any future power increases you may make to your Mustang.

 

First Gear Ratio
3.35:1

(approximate)
Transmission Model
OEM T5, T45, TR-3650, TR-3550
TR-500, TR-600
Rear Gear Ratio Standard TA Heavy Duty TA
Max. Dynojet Torque
RWT (lb-ft)
Max. Dynojet Torque
RWT (lb-ft)
4.56:1 250 390
4.30:1 275 425
4.10:1 290 450
3.73:1 330 510
3.55:1 350 545
3.27:1 390 600
3.08:1 425 650
2.73:1 484 738



First Gear Ratio
2.90:1

(approximate)
Transmission Model
Close Ratio T5, TR-500, TR-600
aftermarket T-56, 4R70W
Rear Gear Ratio Standard TA Heavy Duty TA
Max. Dynojet Torque
RWT (lb-ft)
Max. Dynojet Torque
RWT (lb-ft)
4.56:1 289 450
4.30:1 318 491
4.10:1 335 520
3.73:1 381 589
3.55:1 404 629
3.27:1 450 693
3.08:1 491 751
2.73:1 559 852



First Gear Ratio
2.40:1

(approximate)
Transmission Model
C4, C5, C6, AOD, AODE
Rear Gear Ratio Standard TA Heavy Duty TA
Max. Dynojet Torque
RWT (lb-ft)
Max. Dynojet Torque
RWT (lb-ft)
4.56:1 349 544
4.30:1 384 593
4.10:1 405 628
3.73:1 460 712
3.55:1 488 760
3.27:1 544 837
3.08:1 593 907
2.73:1 675 1030



What if my car exceeds the listed engine torque rating?
The MM Heavy-Duty Torque-arm has been used without problems on cars with over 1,000 ft-lb of engine torque. Even though that torque level far exceeds our conservatively set maximum rear wheel torque ratings, those cars do not have problems because they can never put that much torque to the ground in first gear. If they try to do so, the tires simply go up in smoke. The torque-arm has a lower load placed on it once the transmission is shifted into the higher gears because there is less multiplication of engine torque. In the higher gears the full amount of engine torque can be applied to the tires without spinning them, and without overloading the torque-arm.

Do I need subframe connectors?
Yes. Your Mustang must have suitable (welded-in) subframe connectors installed before installing an MM Torque-arm. The MM Torque-arm's front crossmember attaches to the subframe connectors. While Maximum Motorsports Full-length Subframe Connectors are suggested for best performance, they are not mandatory. See the table below for the minimum size requirements for subframe connectors.

Subframe Connectors - Minimum Required Dimensions
Shape: height X width The tube wall thickness must be at least:
Rectangular: 1" X 2" .120" wall
Rectangular: 1-1/4" X 2" .083" wall
Rectangular: 1-1/2" X 1-1/2" .083" wall
Round: 1-1/2" diameter .120" wall



Do I need a Panhard Bar?
Yes. An MM Torque-arm installation requires that a suitable Panhard Bar be installed first. The geometry of the Maximum Motorsports Panhard Bar compliments the MM Torque-arm, and provides the best performance for your Mustang. If another company's Panhard Bar or Watts Link is installed, the roll center may not be at the optimum height to work well with the MM Torque-arm.

If you intend to use a Panhard Bar other than MM's, please contact us to confirm its suitability.

Should I change my springs?
Yes, but only the rear springs... To take full advantage of the improved rear grip provided by the MM Torque-arm Suspension System, the rear spring rate should be increased from what is typical with a 4-link suspension. This will help optimize the handling balance so your Mustang will have the best performance possible. There is no need to change your front springs solely because of a Torque-arm installation. MM designed stock-location rear springs specifically for use with a Torque-arm. The table below matches the appropriate rear spring for use with a torque-arm to various front springs. Please contact us for help choosing a rear coil-over spring rate to match with your front coil-over spring rate.

Front Spring Rate
(lb/in)
Use This Rear Spring
490-575 H&R 51650 or 51651
575-800 H&R 51650.99
800-900 MM 42TA5
900+ MM 43TA7
Coil-over 175-250 H&R 51650.99 or MM 42TA5
Coil-over 250-325 43TA7
Coil-over 350 & up Requires coil-overs



Do I need to change my rear lower control arms?
The rubber bushings of the stock rear lower control arms allow far too much fore and aft deflection for proper axle control. For the best performance from the MM Torque-arm Suspension System, also install bind free MM Rear Lower Control Arms.

Will my exhaust system need to be modified?
Maybe, it depends.

  • The MM Standard-Duty Torque-arm clears most stock H-pipes, and many aftermarket H-pipes and X-pipes. If any exhaust clearance problems are encountered, they usually require only minor exhaust alterations.
  • The MM Heavy-Duty Torque-arm does require specific modifications to the exhaust system. Any competent muffler shop can easily perform these simple changes. See the MM Torque-arm installation instructions for more details.

Can I read the instructions before I purchase?

Do I have to remove my upper control arms after installing a Torque-arm?

  • Yes, the upper control arms must be removed.
  • The Torque-arm is not an add-on traction device. It is a fundamental change in the rear suspension design.
  • A Torque-arm suspension is a variation of a 3-link suspension. Plus a Panhard Bar.
  • Leaving the upper control arms in place would cause massive suspension binding because you would have both a 4-link and a 3-link suspension on the same car, with both systems trying to cause their own particular rear suspension motion.