High Performance Transmission - Transformation

There are, of course, other choices when it comes to GM overdrive transmissions, notably the 4L80-E and 4L85-E. Found primarily in heavy-duty trucks, the L80 and L85 certainly offer robust torque capacity ratings (440 ft-lb and 460 ft-lb, respectively). But, they are designed for truck applications-specific gear spacing and a 2.48 first gear. "The L80 and L85 are better suited to big-block applications," says Jim La Fontaine, lead systems engineer for transmissions at GM's Performance Division. "The L65 is suited to small-block engines; it's designed to fit with the drivetrain of a small-block-powered vehicle to make installation relatively simple."The L65 has another important advantage over the L80: it's lighter. A 4L65-E weighs about 55 pounds less than an L80 or L85.

When ordered through a GM dealership, the 4L65-E has a list price of $2,595, not including the necessary controller (we're told an inclusive kit is in the works). However, most dealers will be able to sell the L65 for about $2,200 or less.

Yes, you could probably upgrade an existing L60 for less, but we think the thoroughness of 4L65-E's revisions make it an attractive alternative. It also offers the benefits of being brand new and warranted. Heck, if it's strong enough for the 5,800-pound Escalde AWD, it ought to handle your late-model Firebird or possibly your vintage LeMans.

Cable X: Abbott Enterprises' quick fix for using an electronic transmission with a mechanical speedoDespite the performance and economy advantages of using an electronically-controlled automatic transmission in your vintage ride, there's a potential hiccup: the transmission's electronic speed signal has no provision for a mechanical speedometer.

Abbott Enterprises, of Pine Bluff, Arkansas, has a solution. Its Cable X converter transforms the electronic signal of the transmission into a motor-driven output that drives a traditional mechanical speedometer.

In a nutshell, the $300 Cable X is a box with electronic connections on one side and a mechanical cable hook-up on the opposite side. A motor inside the box turns the speedometer cable based on the signals received by the electronic transmission.

"It's an easy install," says Abbott's John Ware. "There are just three wires for the transmission and simply the cable hook-up for the speedometer."

Ensuring the speedometer's accuracy falls to adjustable dip switch settings on the Cable X box, which calculate the correct number of pulses per mile based on the transmission gear (number of teeth), axle ratio and tire size. Abbott Enterprises says the device is accurate to 2 percent of the transmission's electronic signal.

"The dip switch programs the correct speed formula," says Ware. "Overall, it's a simple procedure."

Simple also describes the idea to bring the Cable X to the enthusiast market. Previously, Abbott Enterprises' existence depended solely on the trucking industry. The company manufactures a variety of tachographs and other speed/timing equipment for the over-the-road crowd. But the growth of GPS navigation and tracking cut into Abbott's core business.

"We had a couple of car enthusiasts at the company who suggested the Cable X would be great for older cars using modern transmissions," says Ware. "Frankly, we didn't think there would be much of a market for that application, but the phones haven't quit ringing. The response has been terrific."

Clearly, great ideas are where you find them-even if it's just a twist on an old one. -BK

A Brief History of the GM Modern OD TransmissionsIntroduced in 1982, the 700-R4 was one of General Motors' first production automatic overdrive transmissions. It shared the limelight with the B-O-P-specific 200-4R, which was found in countless G-bodies, Cadillacs, and other larger GM vehicles. (Thanks to a "universal" bolt pattern, it found its way into some Chevys, too.)