Wavetrac Differential 12 Bolt 9"Many differentials on the market today provide little to no grip under low torque conditions. Moser Engineering’s new 35 spline WaveTrac differential uses a patent-pending design to automatically improve grip in low-torque conditions. Made in the USA from superior materials, it comes with a Limited Lifetime Warranty from Moser as well.

Wavetrac differentials are available from Spohn Performance on any Moser Engineering 12 Bolt or Ford 9″ rear ends. To see what is available for your application shop the Spohn Performance online catalog. For an even more detailed technical explanation visit the Spohn Performance WaveTrac Details page.

12 bolt 9" wavetrac differential

WaveTrac Differential

Wavetrac Differentials: Enhanced No-Load Bias Ratio via its Wave Design Center Pack

One of the known shortcomings of a typical torque biasing differential is its loss of drive (behaving much like an open diff) under zero or near-zero torque conditions (for example, when there is ‘no-load’ applied through the drivetrain, either at vehicle stationary and/or transition from engine driving vehicle to engine braking and back).

The Wavetrac® differential uses a patent pending design to improve grip in low traction conditions. Precisely engineered, converging / diverging wave profiles are placed on one side gear and its mating preload hub. As the two side gears rotate relative to each other, each wave surface climbs the other, causing them to move apart. This imparts an increased normal force through the side gears, increasing the bias ratio as a function of load. This increase occurs automatically only when conditions find it necessary, and it ‘reverts’ back to its nominal bias ratio quickly and seamlessly, maintaining optimal drivability and performance at all times. It’s like having two differentials in one: you get the benefit of a higher bias ratio when needed without detriment to the car’s handling.

These friction plates provide a mechanism to tune the response of the differential as a function of applied torque load. The applied torque load manifests itself as an axial load from the differential pinions into the housing. This axial force is then considered a normal force into the friction plate, and as a function of the effective coefficient of friction, will provide a resistive torque to the rotational motion of the differential pinions. The resistive torque will add to the resistance of relative rotation of all components within the differential. The resistive force, however, is non-uniform since it is a function of the axial load from the differential pinions. The unbalance of the resistive torque will manifest as non-uniform energy absorption within the differential causing a bias ratio.

Designed from a clean sheet, the new Wavetrac Differential brings current gear technology to the market. Internally, its gear tooth forms are optimized for strength and improved oil film retention over competitive designs. Our gear package is smaller, reducing overall mass, yet is more durable. Attention was also paid to the side gear/axle interface, putting as much material thickness as possible in this critical area – most important when power levels get high.

Each Wavetrac Differential is crafted from the highest quality materials available. The internal gears are made from high strength 9310 alloy steel. The diff bodies are machined from case hardened steel billet. To complete the package, every Wavetrac® differential is built exclusively using high quality, high strength fasteners from ARP, the world leader in fastener technology.

  • New WaveTrac 35 spline differential uses patent pending design to increase grip under low-torque
  • Uses superior construction and material for a tough differential that is maintenance free
  • Comes with a Limited Lifetime Warranty

Contact Spohn Performance at 1-888-365-6064, by email at tech@spohn.net or visit our website at www.spohn.net for more information.


Spohn Performance’s G-Body tubular front a-arms are featured on RPM Media’s “Project Stress Relief”. RPM Media is a premier high performance magazine publisher in Canada.

Every car needs a good solid foundation, and anyone who knows G-bodies knows that there are certainly some faults with the design of their frame and some weak points that need to be addressed with either using a big horsepower motor, or even turning it into a hopping low rider.

We started by taking our Craigslist found $100.00 frame and having it sand blasted. Once we got our frame back, we started reinforcing all of the common spots like boxing in the frame and beefing up the rear control arm mounts. We then cut out the unused portions, welded in our new coilover mounts and started to smooth out the frame for its body matching Charcoal epoxy paint job……

Please check out www.projectstressrelief.com for expanded coverage including more pictures of the project and more information on the build.

Yes, it’s been a little while since we last brought you an update on Project Grandpa, our 1982 Caprice whose longing to see 11’s and still be nimble enough to master the autocross track. Yes, our ambitions are high, and to be honest, saying Grandpa was a little weak in the knees would be like saying a Corvette is a little faster than the Prius – a huge understatement.

OK, we know what you’re thinking: Seriously, a ’82 wagon? We get it, but
Grandpa is going to be the ultimate sleeper, running 11’s and even
tackling the road course. Can we make this happen? Stay tuned to see.

This abused wagon was in desperate need of major surgery to repair the crumbled bones and joints that were the shocks, control arms, and pretty much every suspension part on this car. If we were going to be able to claim this car a success, this is where we really needed to shine.

But before jumping straight into mastering the air element, we needed to lay a strong foundation on which to operate around our fine tuned air bags. Here’s a quick recap on where we’ve beefed up Grandpa, all in the ongoing quest to install our mean 655hp Dart big block 509.

Big thanks go to Dart, JE pistons, Howards,K&N Filters, Harland Sharp,
Moroso, Mallory, COMP Cams, Quick Fuel Technologies, and Professional
Products for making this rat motor the perfect plant for our Project

Wait, a what? That’s right, we somehow convinced Dart to build us this wickedly potent 650-plus-horsepower powerplant for good ol’ Gramps. This monster rat started with a Dart Big M block, with a stout 4-inch-stroked Howards Pro Max crank, billet rods, SRP pistons, a COMP Xtreme Energy Hydraulic Roller cam, topped with a Dart single plane intake and a Quickfuel Q 850cfm carb. When dyno’ed, this big ol’ boy pumped out 655hp at the flywheel.

Our factory suspension just couldn’t possibly handle the torque and torsion
that we knew we were going to be throwing at it. That’s why we went to
Spohn Performance for some serious suspension upgrades.

Thanks to help from Spohn Suspension and Energy Suspension, Grandpa was outfitted with new rear control arms, front sway bar, and steering – plus we were able to completely rebuild the front control arms. We knew that our 509 was going to push our Caprice’s suspension to its limits, so new, stronger and lightweight control arms and sway bars were just what the doctor ordered.

Being able to get all that power produced by the Dart block to the
pavement would take the right rear, and that’s why we went to Currie Enterprises to build us the right 9-inch. Fitted with a Detroit Locker and 4.10 gears, we’re going to be pulling a whole lot of sheetmetal down the quarter mile.


Is Al Marlow the Fastest Man on 275 Drag Radials?

Posted by Spohn Performance | 10/13/10 | Tagged 1. News Releases

Al Marlow Drag Radial Camaro

Al Marlow - 4.84 @ 150 MPH - 1.25 60' on a 275 Drag Radial

Is Al Marlow the fastest man on a 275 drag radial? We think he is!

On Friday October 8, 2010 at Maryland International Raceway Al Marlow laid down a blistering pass of 4.84 at 150 MPH.

The complete Spohn Performance suspension hanging under this beast had the 275 Hoosier drag radials digging out a 1.25 60′ time. How’s that for traction on a small tire?

Congratulations go out to Al Marlow and his crew for their fantastic 2010 season so far.

Al Marlow runs a complete Spohn Performance Suspension - do you?


F-Body Camaro Firebird Front End Steering Rebuild Kit
Our popular front end steering rebuild kits for the 1982-1992 F-Body Camaro and Firebird and for the 1978-1987 GM G-Body are back in stock and ready to ship.

Along with our complete packages we are also stocked up on all of the individual components for those of you looking to grab single parts.

Follow these links to check everything out:

1982-1992 F-Body Camaro and Firebird Front End Steering Rebuild Parts

1978-1987 G-Body Front End Steering Rebuild Parts