GM 8.3L Duramax Diesel: Gale Banks Does the Math
Gale Banks breaks down the math behind GM’s new 8.3L Duramax V8 (L6P “Mongoose”), evaluating its 555 HP rating, CGI block, flat torque curve, and how a Derringer tuner on an L5P beats it today.
Jay Leno’s Tank Car is just one of several high profile development programs ongoing in the Banks Advanced Prototype Engineering labs. One of the Banks Sidewinder Duramax Diesel race trucks can be seen in the background. At this point in the Tank Car’s transformation, all of the fabricated intake components and the fuel rails were sent out to be polished.
While the intake and exhaust manifold work was being completed, another team of Banks engineers and technicians was coordinating the development of the electronic fuel injection system. Bosch came on board and supplied all of the components needed to do the conversion along with technical support. Although many of these were off-the-shelf items, a lot of work was needed to adapt them to the AV 1790 engine. Here Test Engineer Chuck Swart installs one of several custom wire looms the Banks team made up to connect the various EFI sensors.
The heart of the EFI system is this Bosch MS 2.9.1 engine management controller. Don’t go looking for one of these at your local Mercedes dealer, you won’t find it. It’s Formula One issue from the Bosch Motorsport program and Jay got the only spare unit available in the US.
We mounted the controller under the dash with bulkhead cable connectors through the firewall to protect this priceless processor. The unique bracket turned out so nicely that it was a shame to hide it under the dash.
The Bosch EFI system senses crank, cam, and throttle position, engine speed, intake air temperature and pressure, fuel temperature and pressure, oil temperature and air/fuel ratio. Because the AV 1790 is air-cooled, engine temperature is monitored through this Bosch oil temperature sensor we installed above the oil filter.
A trigger wheel and proximity sensor are used to relate the crank and cam positions to the timing of the injection event. The Banks team designed and machined this trigger ring and adapter flange to mount on the crank stub shaft in the accessory gear case at the front of the engine. A billet aluminum gear cover with an integral boss was machined to position the proximity sensor in line with the trigger ring.
The cam position sensor likewise required a trigger wheel. The camshafts on the AV 1790 V12 are driven by a pair of intermediate shafts and right-angle spur gears at the front of each cam. In this case we modified the existing left-side gear cover to accept a sensor, and machined a trigger wheel to indicate the No. 1 cylinder position.
Twin oxygen sensors will sample the spent gasses from combustion at the inlet to each turbocharger and adjust the air/fuel ratio based on throttle position, RPM, temperature, and other engine conditions.
During the initial tuning process, we’ll use thermocouple pyrometers to indicate the exhaust temperature for each of the twelve cylinders. These leads will connect to a data logger that displays the temperatures on a bar graph. The Bosch MS 2.9.1 EFI controller can tailor injector delivery for individual cylinders so we can adjust the exhaust temperature in each cylinder.
Hey, All the polished stuff is back! Next time we’ll start the assembly and installation of the fuel system, and maybe start installing some of this shiny stuff on the engine.
Gale Banks breaks down the math behind GM’s new 8.3L Duramax V8 (L6P “Mongoose”), evaluating its 555 HP rating, CGI block, flat torque curve, and how a Derringer tuner on an L5P beats it today.
Discover the dirty secret hidden in factory Duramax oil pans: an elevated drain plug that traps nearly a half-quart of contaminated sludge every oil change, and how the Banks CoolRunner pan cures it with complete drainage, FlowThru cooling fins, and +2 quarts capacity.
Banks introduces the world’s only true 5-inch DPF-back Monster Exhaust for 2024–2026 Duramax 6.6L trucks, using a patented Exhaust Pressure Module to cut backpressure without triggering check engine lights or melting trailers.
The Banks R866SC V8 6.6L Supercharged Diesel is an engineering powerhouse delivering 600-650 horsepower. Featuring a 3.8L Whipple supercharger and custom FEAD, this complete package is built for extreme performance.
Banks Derringer High Output tuner does more than just add power to your 2024–2026 Duramax 6.6L. Level 2 is specifically calibrated for improving fuel economyby adding more boost and optimizing fuel injection. And, Level 2 delivers an impressive 60 hp and 90 lb-ft to the wheels. For even more power, bump up to Levels 3-6 for power increases up to 86 hp and 178 […]
On all 6.7L Cummins, the factory grid-heater bolt is a known risk: if it breaks loose and reaches cylinder #6, engines are replaced—not repaired—an outcome costing north of $30,000. If you do nothing: the stock grid-heater bolt stays in the system—every start is a roll of the dice, and other replacements “fixes” still choke air flow. […]
Hector’s 2015 RAM 3500 threw an intake-heater code, then his remote start system stopped working. He pulled his intake plate after reading about the killer grid heater bolt. To his horror and delight, he saw “the nut had broken off and was just sitting there” — one drive from disaster. Rather than install another factory heater plate, […]
Your 6.7L’s stock intake elbow kills airflow with its sharp bend and restrictive air path. That added restriction makes the turbo work harder and dulls response. A Banks Monster-Ram intake elbow takes a different route—literally. We rerouted the #1 fuel line and replaced the restrictive grid heater which allowed us to open the air path and remove […]
RAM 6.7L engines can suffer catastrophic damage as a result of a bolt inside the factory grid heater, which melts and drops into the intake manifold. In this 8-minute close-up, you’ll see exactly what fails, where to look on your truck, and the upgrade that removes the weak link. If you own a 6.7L, this […]
Banks Power by the Numbers breaks down the real data behind a record-setting 2025—from millions of video views to testing fuel burned and parts shipped worldwide.
A Canadian diesel mechanic visits Banks Power and gets a firsthand lesson from Gale Banks on air density, cold starts, and real engineering behind reliable diesel performance.
“This video is a huge full-circle moment for me,” says an emotional Dave Bell, owner of Dave’s Auto Center in Centerville, Utah and the star of the wildly popular YouTube channel of the same name. “I’ve looked up to Gale Banks since I was 15 years old,” Bell continues. “His engineering and genius has paved the […]