TCI EZ-TCU and Upgrades for Biting the Bullitt’s Streetfighter 4L80E

Selecting the right transmission for your project car is critical to its reliability and durability. With that in mind we knew that our project Biting The Bullitt would need a tough transmission capable of withstanding its 1000+hp supercharged fury. We also wanted a transmission that would allow the car to still comfortably cruise on the street and not cause us to stop at every gas station we saw on the way to our destination.

If you’ve been following project BTB then you’re already aware that we’ve chosen a TCI Transmission Super Street Fighter 4L80E transmission for this project.  We covered the installation previously in another story. This transmission offers a ton of great features and will not only stand up to BTB’s insane power output but should also give us years or reliable service on the street and at the drag strip.

We covered installing the transmission in January 2012, now we'll cover installing the control system and a few other components

The 4L80E also features a gear ratio setup of 2.48 first, 1.48 second, 1.00 third and a 0.75 OD for fourth. This is a fairly typical ratio setup for a four speed automatic. One thing we really like though is the 2.48 first should help hit the tires a little softer on drag strip launches (or let us launch at a higher RPM). The .75 over drive fourth gear will let us cruise home on the interstate without going insane from high RPM drone, as well as be a little easier on the engine and other parts since we’ll be turning less than 6,500 rpm.

Building a Strong Transmission

 Proper TPS Voltage

Since our transmission is electronically controlled it relies on a throttle position sensor to shift properly in automatic mode as well as control transmission line pressure which has a direct impact on shift firmness and speed. The TPS must be connected to the carburetor linkage and then calibrated to 0.050 volt with the throttle fully closed. This gives the proper throttle position signal to the EZ-TCU and ensures there are no error messages or shifting problems. .

Nearly all TCI transmissions start life as a core. Cores come into a TCI facility where they are disassembled and put through a rigorous inspection process. All of the wear parts including clutches, steels and seals are discarded. Valve bodies are sent out to a separate part of the facility for reworking and modification.

Transmission cases are thoroughly inspected during and after the core tear down process for signs of wear, defects or fractures to ensure they are as strong as possible. Drums and input shafts, also known as hard parts, are also scrutinized carefully to ensure they can be used in the build process. Once these parts pass inspection they are sent to designated areas for modification or reconditioning and will later be installed in the transmission application that they are best suited for.

Strong Origins

Our project BTB is making serious power and we need a transmission that can handle the punishment. With that said, the 4L80E is already a stout transmission originally, TCI’s Scott Miller told us, “There’s a lot of parts in this transmission that are already very strong to begin with.”

There’s a lot of parts in this transmission that are already very strong to begin with. – Scott Miller

All Super Street Fighter transmissions are built using some of the best and toughest parts available in the transmission industry. These include Kolene treated steels, Alto Red Eagle clutches, Red Eagle lined extra-wide power-bands, larger diameter servos, new sprags or roller clutches – enhanced hard parts where needed and an improved transmission lubrication system.

Every TCI transmission is built in house by one of TCI’s dedicated in house transmission builders. These builders are brought up through the company and must pass a three month long training program to be allowed to build transmissions. Their sole job at TCI is transmission building. This allows them to be focused exclusively on building the product, and not distracted by other issues.

Our particular Super Street Fighter has had its original GM bell housing machined off the case to make it modular. This allows it to be installed in a variety of applications, including our small block Ford. The valve body has received a different set of springs, and modified separator plates to mechanically firm up the shifts. Other modifications to the transmission included updated sprag and input shaft, as well as a billet steel hub.

Additional Upgrades

Since our transmission will be subjected to regular abuse at the strip, and even more cruising on the street we decided to maximize it’s life by keeping it cooler. To do this we installed two additional available upgrades from TCI.

Maximum Cooling

We mounted the Max Cool transmission cooler directly to the front of our radiator with the supplied hardware.

The first is a TCI Max-Cool transmission cooler. This was a simple matter of attaching the max cool lines to the transmission cooler lines for our transmission. Then we mounted the cooler in a location in front of our radiator where it can get cool fresh air. This heavy duty cooler already has the mounting plates pre-drilled. It’s design increases the surface area available for cooling and can lower transmission temperatures by as much as 33%. We’re using part number 824103 as recommended by TCI.

Pan Upgrade

Our second upgrade is one of TCI’s Max Cool transmission pans, part number 278000. This pan features additional cooling fins to further cool the transmission fluid as air passes under the car and across the fins. The deep design also allows for 4.5 extra quarts of fluid capacity. This too allows for better transmission cooling since the heat can be spread across more fluid, and TCI states that the Max Cool pan will reduce temperatures 20-30 degrees over the stock pan. The pan’s design also actually increases transmission strength with its thick cast aluminum construction, acting as a girdle for the bottom of the transmission. All the parts necessary for installation were included, and it’s literally a job that only takes a few minutes of dropping the old pan, swapping on the new one and refilling the lost fluid.

Side by side with the original 4L80E pan on the left and the new TCI Max Cool Pan on the right, the differences are obvious


With over 1,000 hp on tap, we wouldn’t fill our transmission with just any off the shelf ATF. We need something that will stand up to the high heat, as well as offer our transmission the best performance possible. We chose to fill our 4L80E with 12 quarts (yes that’s a lot of fluid!) of TCI Max-Shift transmission fluid, we’re using the racing formula, part number, 950620.

Max Shift offers high resistance against thermal breakdown, plus TCI states that it exceeds the standards of both Mercon and Dexron type fluids. It’s also compatible with other types of transmission fluid, meaning if we were simply servicing our transmission we could add Max Shift to it with no worries regarding compatibility.

Transmission Control

The Super Street Fighter 4L80E is an advanced transmission that was intended from the factory to be computer controlled. Obviously our project BTB was not originally equipped with a GM transmission. This creates potential dilemma in how to properly control the unit.

The EZ-TCU control system is a revolutionary way to install and control a transmission that requries computer controls

Far left: The brains behind the EZ-TCU system is the EZ-TCU unit itself, developed for TCI by FAST. Center Left: We mounted our EZ-TCU under the driver's seat for easy access. Center Right: the harness for the transmission was routed through a hole in the transmission tunnel. Far Right: The transmission harness is simply a plug and play connection.

Through the years a multitude of controllers have been on the market for operating a computer controlled transmission. Some have come and gone, some are extremely complex, while others are well past their prime.

The solution for us comes directly from TCI in the form of their EZ-TCU. TCI worked directly with FAST (Fuel Air Spark Technology) one of the performance industry’s top computer control manufacturer’s to develop the EZ-TCU. Miller says, “The name fits it perfect, it’s a stand alone transmission control unit based on the FAST EZ-EFI format.”

Our system included TCI's slick Outlaw shifter and we connected the yellow wire to the harness for the shifter for our upshift button and the red wire for the downshift button. Using these two buttons will allow us to shift trigger finger style, no need to slap a shifter or slide through the correct pattern.

The EZ-TCU takes the guesswork out of setting up a computer controlled transmission and does so at an affordable price. For what an average tuner might charge just to get another control system dialed in for your car, you can buy a complete EZ -TCU and harness kit. Included in our EZ-TCU kit was the EZ-TCU, the hand held controller which can be mounted inside the car, and the harness for our transmission. We complimented the install with a TCI Outlaw shifter that contains two buttons for manually up shifting and down shifting the 4L80E.

The EZ-TCU package comes complete with a harness and shifter. Installation is a matter of connecting a power, ground, ignition on, and a handful of other wires and connectors. It is important to note that TCI specified the power and ground must be run directly from the battery, and that no other systems should tie into these power or ground feeds for power sources of their own. Also since this is a computer controlled harness, tach signal must come from a tachometer drive module or ignition box, not from the coil. All wiring should be routed as far away from ignition system or other electrical components as possible to avoid electronic noise interference, which could affect the unit’s performance, hence why we mounted it under the seat.

The harness plugs directly into the connection on our 4L80E transmission. There is also a connection four our throttle position sensor. This sensor is mounted on the passenger side of the engine bay and connected to the carb linkage. It is necessary for the control system to know where the throttle position is.

We connected the blue wire to our Racepak SmartWire so that we can choose between manual and automatic shifting modes. Our TCI Outlaw shifter is equipped with two momentary buttons on the shift handle. These buttons are built into the grip area and allow us to shift up or down with a simple click when in manual mode. A pretty cool feature whether on the street or the track. The system is also compatible with TCI’s paddle shifter setup if owners prefer to go that route. The red wire in the harness connects to the button for shifting down, while the yellow wire is for the button that controls shifting up to the next gear.

Left: We now select 4L80E as our transmission type. Center Left: We then enter our rear tire size. Center Right: Since we're using our Racepak SmartWire and Racepak dash in this car we must select the proper speedometer sensor output signal. For our application it is 16,000 Pulses Per Mile, or PPM. Far Right: We now enter our ring and pinion gear ratio which is 3.70

There is also an economy mode trigger wire that we connected to our SmartWire system. This changes the shift firmness and timing of the gear changes in automatic mode, to more comfortable parameters for cruising patterns. It’s nice for those lazy afternoon cruises, but we can go right back to the wild side with the simple flip of a switch.

Easy Setup

With all of the connections made and checked we simply connect the hand held unit to the cigarette lighter (or the plug can be cut off and wired to a switched 12 volt source) and the EZ-TCU, turn your ignition key to on, then follow the on screen prompts and instructions. The EZ-TCU will develop a basic strategy based on the answers to some simple questions in the setup wizard.

The EZ-TCU also allows us to customize the transmission tune via the handheld controller if we so desire. This could benefit us at the track if we think there’s something to be gained ET wise in the shift strategies or on the street in further adjusting our transmission settings for more comfort or better street manners. All of these settings are changed via the handheld controller and are based on load, speed, throttle position, and RPM.

Left: We now enter our Maximum shift RPM, this is for automatic operation the highest point you want a shift to occur. Center Left: Make sure the throttle is closed/idle, the EZ-TCU uses this as a key calibration parameter and part of the critical TPS reference signal. Center Right: We will now calibrate wide open throttle. This should be done inside the car, engine off, with the accelerator pedal to the floor. This will ensure the most accurate TPS reading. Far Right: This message is displayed during both the idle and wide open throttle calibrations, do not fluctuate the pedal during this time or an incorrect reading could be recorded.

The name fits it perfect, it’s a stand alone transmission control unit based on the FAST EZ-EFI format. – Scott Miller

Once all the settings are finalized we can take the car for a test drive and see how it performs. Adjustments can be made via the handheld controller if needed, although for no we’ll leave it as is. The handheld unit can be stored in the car’s glove box, or could even be installed to act as a secondary dash. It can display all manner of data about transmission operation. Some of the info it’s capable of displaying includes speed in MPH, transmission temperature, current gear selected and line pressure.

With our transmission squared away, project BTB is one step closer to hitting the street and strip for some full throttle passes. We’ve got piece of mind knowing we have a transmission that can handle the kind of horsepower we’re throwing at it. We also have some comfort in knowing that after a long day on the track we can simply switch the car to full auto and economy mode and cruise back home in comfort.


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About the author

Don Creason

Don Creason is an automotive journalist with passions that lie from everything classic, all the way to modern muscle. Experienced tech writer, and all around car aficionado, Don's love for both cars and writing makes him the perfect addition to the Power Automedia team of experts.
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