The Hughes Transmission crew has years of experience with the 4L80E transmission and they feel it is the perfect choice for those who want the strongest overdrive automatic available and that was reason enough for our decision.
According to Hughes there is much about the 41480E. They have a gear spread that allows hard, off-the-line acceleration with an overdrive top cog for reduced engine rpm for long distance cruising—ratios are First, 2.48:1; Second, 1.48:1; Third, 1.00:1; and Fourth, 0.75:1. In addition these transmissions can be made to withstand huge amounts of horsepower with modifications Hughes has perfected. Add to that a torque converter that allows higher-than-stock stall speed for maximum torque multiplication along with a lock-up function, which virtually eliminates all heat buildup in the converter at cruising speeds and improves efficiency, and you’ve got the best in terms of performance and practicality.
Like all contemporary automatic overdrive transmissions the 4L80E requires an electronic control unit to operate. Hughes offers controllers that are pre-programmed and require no software, laptop, or PC for installation, tuning, or proper function and a pre-terminated wiring harness for simple plug-and-play operation is included. When required, a throttle position sensor (TPS) kit and mounting bracket that will work with virtually any carburetor is optional, with EFI systems the Hughes harness is simply spliced into the existing TPS.
Automatic Transmission Basics
While automotive automatic transmissions may have two, three, four, or more gears, manual or computer controls, and vary in complexity, the basic internal parts remain the same, there are just more of those parts in some transmissions than others. Here’s a look at the major components of an automatic transmission and some of the usual performance upgrades:
This is what connects the engine to the transmission. Not only does it allow the engine to keep running while the ear is stationary, but it can also provide torque multiplication when accelerating from a standstill. For a simplistic explanation of how a torque converter works, picture what would happen if two electric fans were facing each other and one was turned on. As the one under power began to turn and move air, the other one would also begin to turn. If you can visualize that, you’ve got the basic idea of how a torque converter works. In a torque converter, both fans are in a container: one is connected to the engine and the other to the transmission, and oil is used rather than air.
As might be expected, there is some slippage inherent with a torque converter; so many overdrive automatics now have converters with a hydraulically applied internal clutch that hooks the transmission directly to the engine for increased efficiency. While better fuel mileage is often considered to be the advantage of a lockup converter :here is another, often overlooked, purpose. The higher ratio provided by an overdrive Fourth gear can put an additional load on a conventional converter causing excessive slippage even in light throttle cruise conditions. That slippage creates heat and heat’s the enemy of an automatic transmission. When used with an overdrive automatic a lockup style will lower engine speed in cruise conditions and lengthen the transmission’s life. Overdrive automatics and lockup converters are made for one another.
As gears go, planetaries can do it all. Made up of three elements— sun, ring, and planet pinion gears—they can provide forward or reverse rotation, a speed increase, constant speed, or a speed reduction.
Three things are necessary to make planetary gears operate: an input (power from the engine), an output (power going out), and a reactor (one of the elements is held stationary). The gear ratio and the direction of travel depend on which element is performing each function. Most transmissions have more than one planetary gear set to provide a variety of gear ratios.
Bands And Clutches
Bands and clutches hold the reactors stationary. An automatic transmission goes into gear by holding one part of a planetary gear set stationary with a band or a clutch that is applied by hydraulic pressure. One reactor is released and another applied when the transmission shifts gears; the transmission is in Neutral if no reactor is applied. If you’ve ever been in a car and the transmission felt like it was slipping, that’s exactly what was happening—the band or clutch pack wasn’t holding the reactor stationary and it was slipping and not transferring full power. In an extreme case, the clutches, or band, don’t hold at all, and one or more gears (and in some cases, every gear) stops working as a result.
The valvebody is the hydraulic “brain” of the transmission; it controls the shifting of gears by controlling which reactor is applied and when, Some transmissions use hydraulic pressure from a governor, throttle valve, or vacuum modulator to determine shift points, while many contemporary versions use computer-controlled electromechanical servos.
Let’s start with the torque converter. In many cases, the stall speed of the converter is increased. Simply put, stall speed is the rpm that the engine will reach with the transmission in gear, the brakes applied, and the throttle held wide open. The higher rpm simply allows the engine to produce more power, which will launch the car harder from a standstill. The downside is that higher stall speed converters will slip more in “normal” use. That can create excessive heat, which is what damages transmissions. Of course the perfect solution is a lockup converter with increased stall speed—that’s the best of both worlds.