Lucas Bell 
In the world of automotive performance, diesel engines aren’t a particularly popular launching point. Sure they don’t sound the best and they only rev a fraction as high as their gasoline-powered counterparts, but diesel engines have the potential to be serious performance monsters. That is exactly what Gales Banks from Banks Power shows us in his recent YouTube video, with some help from a ridiculous Duramax V8 that produces over 900 horsepower. Did we mention that it’s almost entirely stock?
For fans of anything with a turbocharger attached, Gale Banks is a name that you must learn to admire. The 78-year old hot rodder is one of the forefathers of turbocharging technology, working with everything from military marine engines to salt-flat record holding muscle cars. Banks has always tinkered with diesel motors, but we’re not sure he has ever tried so hard to break one.
In his most recent YouTube adventure, Banks and his team at Banks Power have taken a Duramax L5P V8 diesel and pushed it to see just how much abuse the stock internals can take. While the engine produced well over 850 horsepower in their last installment, Banks is not one to settle. This time, the team reconfigured the airflow of both the intake and exhaust to try and free-up some horsepower.
The idea behind reducing the angles on the exhaust bends as well as straightening the intake piping is a simple premise. The shortest distance between two points is a straight line, and those straighter pathways help with increasing efficiency in the engine. This is achieved through improved cylinder scavenge, which results in lower residual exhaust in the cylinders, improved cylinder fill, lower initial cylinder temps, and lower exhaust pumping losses.
As Banks says in the video, This D-Max is stock from the bottom on the oil pan to the top of the valve train. The only modifications include an upgraded Precision turbocharger, an upgraded oil cooler, a new viscous vibration damper for the crankshaft, and of course upgraded injectors for more fuel. All of the internal bits and bobs are 100% factory spec, and that is absolutely incredible.
In the end these small changes allowed Banks Power to produce 912 horsepower on the engine dyno with this Duramax V8. Not only did the piping changes create nearly 60 horsepower, it also improved fuel use per horsepower by 2.8 percent. While diesels are always thought of as torque machines, this build brings the horsepower to match. The limiting factor in this test wasn’t even the factory parts, as the team has already reached the choke point of the new turbo. Not to worry though, as Precision is supposedly sending a new one on over soon. Could we see over 1,000 horsepower on stock Duramax internals? I think we just might.
