First Gen Cummins Makes 660HP on the Dyno

This is the kind of first gen Cummins build that makes you rethink what an old truck can really do. Tim from Decent Garage brought in his 1991 W250 after two years of work, fresh out of SEMA, and we finally put it through a real tuning session and full dyno run to see what this compound-turbo setup is capable of. This is not a showpiece that never sees the road. It’s a real American truck built with the horsepower and torque to back it up. The walk-around alone shows how much detail went into this first gen. Tim kept the classic paint scheme but packed the engine bay with a P-pump 12 valve, a Banks Twin Ram, Farrell Stage Two pump, Hamilton cam, ported head, and a clean set of compounds with a 272 and 369 that follow a proven Power Driven Diesel recipe for towing power. Everything is done with intention. Nothing flashy, nothing unnecessary, just solid parts working together. Even the intercooler is a custom-cut third gen core built specifically to fit right. The deeper we got into the truck, the clearer it became that this thing was built to do more than sit at SEMA. Once the AFC Live was installed and the engine had a quick warmup, we strapped the truck down and started running it. First hit on the dyno and it blew past the expected 500 horsepower goal before popping a boot. With the pump setup dialed in, the truck settled into a max effort of around 660 horsepower and nearly 1500 foot pounds of torque at only 47 pounds of boost. The tow tune came out strong too, holding a clean 485 horsepower with safe EGT control and a flat torque curve designed for long grades and heavy loads. Everything ran smooth, no leaks, no surprises, just a clean, efficient compound setup doing exactly what it was built to do. If you want to see how a real first gen build performs on the rollers, how the AFC Live changes drivability, and what goes into dialing a P-pump 12 valve for both towing and max effort, you’ll get all of it here. Subscribe for more dyno runs and real diesel talk every week. Power Driven Diesel is a specialty performance shop engaged in the engineering and development of high-performance turbo diesel technologies. Contact Us: 435-962-9555 [email protected] https://powerdriven.com   / powerdrivendiesel     / powerdrivendiesel