Tom Wilson
April 1, 2003
Photos By: Roger Johnson

Horse Sense:
Digging around Auburn Gear's literature, it's clear the ECTED differential is aimed at OEM applications. Imagine the traction tricks you could pull with a computer calling the shots on limited-slip engagement. From nearly fully open to fully locked up and anywhere in between, ECTED technology could soon show up on Ford showroom floors.

Well into the electronic revolution as we are, you'd think all the mechanical questions had been answered. But judging from the seemingly endless yet not-quite-perfect attempts at developing the ultimate differential, we have to say it isn't so. From the hopelessly traction-limited but cheap-and-easy-to-live-with open differential to the amazingly complex and expensive teams of gears such as the Torsen, the quest continues for a differential that is quiet and accommodating on the street yet tough as nails and with cat-on-a-carpet traction at the track.

Auburn Gear, the same industry giant famous in the late-model Mustang world for its popular cone-type limited-slip differential, has just released a new design spun off its original-equipment business that looks to offer a huge range of performance at approximately $600 retail. While that's not pocket change, it is within reach of the drag enthusiast who values full-on, both-wheels-locked traction. That's the sort of bite promised by the new Auburn, because while it functions as a limited-slip during normal street operation, it clamps up into a locker at the flip of a switch.

Various methods of applying a clamping force to clutch-pack-type limited-slip differentials have been tried through the years. Auburn Gear's method is to use an electromagnet (the large round ring with the wire and connector) to provide the desired squeeze. The remainder of the differential is a conventional clutch-pack unit.

Although something of a mouthful with the name of Electronically Controlled Traction Enhancing Differential (ECTED), the idea behind the new unit is simple. A conventional clutch-pack-type limited-slip differential is used, but one end of the differential has a ring-shaped electromagnet while the other end has a plain iron ring. Energize the magnet with a remote mounted switch and the clutch pack is clamped together so tightly between the electromagnet and the iron ring that it functions as a spool. In other words, with the system engaged, the differential isn't-but it is completely locked and functions like a spool, which is simply a solid disc connecting the two rear axles. The combination of limited slip and locker is somewhat unique, as the ARB and other switch-hitting differentials available to date tend to mate fully open/fully locked diffs, not limited slips and lockers.

While clutch-pack-type limited-slip clutches are quite popular-witness the Ford Traction-Lok-Auburn is known in the Mustang world for its cone-type limited slip. It has proven more durable than the clutch pack diffs such as the Traction-Lok, but must not package as well in the ECTED application. Given our passable luck with Traction-Lok diffs, we assume that as long as the clutch packs aren't hammered by 16-year-old enthusiasm for burnouts and power-slides at every intersection, the ECTED clutches will hang in there a long time.

Auburn Gear observes that the ECTED not only makes a great street/strip differential, but it should also be the cat's whiskers in off-road trucks, or even simply as a get-me-unstuck device for snowy and muddy climes. Furthermore, the ECTED technology packages within typical existing differential architecture, so while the Ford 8.8-inch axles get the differential first, we could also eventually see it in 9-inch applications, not to mention the already existing GM 10-bolt units. Auburn also noted the unit is available in stock 28-spline and enhanced 31-spline axle configurations.

The magnet coil in the ECTED does not rotate with the differential. It is rigidly mounted, with a race and ball-bearing assembly behind it providing the stationary-to-rotating interface.

One place we'd not expect the ECTED to shine is the road-racing track. That's only because as a locker, it would promote understeer a bit more aggressively than is desirable. That's not a knock on the ECTED, only a fact of geometry. Road-race cars need robust limited-slip differentials that allow some differential tire movement, not lockers. In other words, dragstrip or street/strip action is where the ECTED will make its mark in the Mustang world.

Installing the ECTED in the rear axlehousing is the same as bolting in any stock-replacement differen-tial. There are a few small additional steps, however. To illustrate the installation, we're running photos of a pro-totype install on a '95 Mustang GT performed at Higgins Ford Performance in Douglasville, Georgia. The installation included one smart option: 31-spline Moser axles. Considering the tire-frying "testing" this sort of application is sure to engender, we're sure it was a smart addition.

Auburn Gear says the ECTED pro-duction and distribution should be all spooled up for 8.8-inch Ford axles by the time this story hits the streets. Both 28- and 31-spline configurations will make it to market in the initial offering, so everyone but 9-inch users are covered right now. So, have fun making two black stripes.