Our 10 Second Ride with a 355 Gets a Hughes Transmission and Torque Converter and Turbo Shop Electronics



By Robert Cassell
Automatic overdrive transmissions have become "the" set- up for the '90s, allowing the
use of steep rear gears for performance while not interfering with highway cruising and fuel mileage, thanks to the big rpm reduction their Fourth- gear overdrive provides. In street applications, the fuel savings alone are probably worth the price of an over- drive, especially if you're running a big- block. And the wear and tear on your engine is reduced, since the overdrive will have you cruising at about 1,000 rpm less on the highway.

The later GM 200-4R and 700-R4 transmissions are excellent overdrives for heavy-duty street and off-road performance applications, and, when modified for higher torque levels, they're still a great choice for serious performance applications.

However, what if you want to take advantage of an overdrive automatic, I but your engine produces really high I horsepower and torque numbers due : to nitrous or a supercharger, and it's exceeding the capabilities of the 200-4R or the 700-R4? Maybe it's time to consider the GM 4L80E electronically controlled four-speed overdrive.

The 4L80E transmission is original equipment for all heavy-duty GM truck applications. It's GM's latest offspring of the TH400 trans, and we all know how tough that piece is. With GM's latest refinements and electronic controls, the 4L80E is stronger and much smarter than its TH400 predecessor, even with its Fourth-gear overdrive. When modified for all-out performance, the way the Hughes Performance Street/Strip 4L80E is, the 4L80E stands alone as I the ultimate setup for extreme-performance applications. And because : Steve Cole at The Turbo Shop (TTS) 1 can program this electronically controlled transmission to suit your specific needs, you can have hard-hitting drag- race-type shifting at full throttle but retain all the comfortable and reliable part-throttle street manners GM has designed into the unit.

The thought of installing an electronically controlled transmission might be intimidating for some. But wait a minute. Installing one of these transmissions with The Turbo Shop's electronic hardware really is simple. Cole has de- signed a foolproof stand-alone computer, wiring harness, tailshaft housing, and all the necessary hardware to make this installation a snap. You can even utilize the OE column shifter, or, for floor-mounted applications, B&M Performance's Mega Shifter can be in- stalled for 4-on-the-floor.

Our ProCharger-supercharged, Lunati small-block-equipped '56 Bel Air has exceeded the capabilities of the 700-R4, as we are approaching the 800hp mark. Installing the Hughes Turbo Shop 4LBOE has solved our trans- mission worries as we prepare the '56 for "A 1O-Second Ride With a 355," where you'll be able to see just how well this transmission operates under extreme conditions.

The 4LBOE has the reputation of being a very large and heavy transmission that can be difficult to install into most Chevrolet cars. Actually, the 4LBOE is not much heavier or larger than the 700-R4. Installing this trans in a '56 Bel Air was painless and did not require any modifications to the trans tunnel or frame.


The Hughes remanufactured 4LBOE starts with a rigorous inspection and many of the original parts are replaced with new high-performance compo- nents. Higher-coefficient friction plates, Kevlar band assemblies, improved lubrication circuits, and extensive valvebody recalibration allow firm, crisp shifts for greater reliability and capacity.

The Hughes Kevlar-lined race band (at Jointer) not only produces superior loading power but also features welded struts for extreme durability. Compare he welded struts to the riveted struts around on the stock band (bottom).

Compared to the stock 16-element intermediate sprag (left), the 34-element sprag (right) that Hughes uses contributes greater holding capacity for second gear.

The pump-pressure boost valve used (left) has two lands to better stabilize it
in the sleeve for improved durability. The stock valve (right) features only one land.

The stock pressure-regulator valvesprings are replaced with heavy- duty springs to boost line pressure to the transmission.

To produce superior "grab," Hughes up- grades all the clutch packs with high- performance Red Race friction plates and Kolene steels. Hughes also modifies the forward and direct clutch packs with an additional Red Race friction plate and Kolene steel for a total of six.

A much stronger 4130 bil/et-steel for- ward clutch hub {Jeft) replaces the OEM cast hub.

The Street/Strip 4LBOE also includes Hughes's valvebody recalibration kit, which includes all the recalibration hard- ware, thus allowing firmer, crisper shifts for greater reliability and capacity.
Gapless spiral-Iock snap rings are used throughout the trans for improved hold- ing power and durability.

The Hughes 3,000-stal/ 11-inch lockup torque-converter assembly starts with a ICNC-machined bil/et-steel bottom cover.

The lockup clutch used in the Hughes converter (right) completely dominates
the OEM clutch assembly. The Hughes clutch assembly features a full 1 inches
of high-static lining.

The turbine hub is manufactured from billet 4130 chrome-moly steel. The vanes are silicon spot-brazed.

All the fins on the turbine and the im- peller are also silicon spot-brazed.

Hughes redesigned the internal sprag with new springs and rollers.

The finished converter also features a process-90 hub and an antibal/ooning plate for extreme durability.

The Turbo Shop produces this computer control box for the 4LBOE. The box is a full OEM control system retaining all the factory test functions and diagnostic abilities.

The Turbo Shop's 4LBOE wiring harness is custom-made to fit each application. The Turbo Shop doesn't cut costs by us- ing standard automotive wire but uses only top-quality, high-temperature, oil- resistant wire in its harness.

The Turbo Shop installs a diagnostics connector in the harness. This connector is used for programming the computer and diagnosing troubleshooting codes. The company also installs a small "system check light" in the connector for quick, proper system function identification.

The Turbo Shop produces this throttle- Dosition sensor box. It relates the throt- tle's position to the computet; which in turn controls shift quality.

This GM brake/converter switch re- places the OE brake switch. It controls the brake lights and releases the lockup torque converter when the brakes are applied.

The Turbo Shop can program a custom shift-quality program to suit the applica- tion. It can also program when the torque converter locks up. All the shift points-upshifts, downshifts, full-throttle shifts, or light-throttle shifts-will lock up in Second, Third, or Fourth at any speed or throttle position. The company also offers the TransMaster software for those who would like to program their own chips. The software allows the user to trim the program for different tracks, altitude changes, or street or highway use. The user needs a 386 or greater IBM-compatible laptop computer to op- erate the TransMaster software.

With the 700-R4 (4L60) and exhaust sys- tem removed from the Bel Ait; Steve Cole lifted the 4LBOE up into place for a test fit without the torque converter. The 4LBOE has a larger oil pan and is slightly wider and longer than the 700-R4, but, besides relocating the crossmembet; there were no modifications to the frame or body panels were necessary to fit this trans in the '56. In fact, we were all surprised by how much room there is in the Bel Air's trans tunnel for this swap.

The Turbo Shop offers three differ- ent mechanical speedometer-drive tailshaft housings. One is for those who want to run a mechanical speedometer in any early applica- tion, one is designed to accept the Corvette torque arm, and the other is compatible with an RV's drum-
brake assembly.


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