Why MORE Horsepower Is LOSING This Diesel Race

Todd, Will, and Myer dig into Fast 72, the new turbo limited diesel racing class that is already turning heads and stacking serious prize money. A single 72 millimeter turbo and a fuel only setup are producing six figure purses, and this episode breaks down why. They start with the actual rules of the class. No nitrous, no water injection, no methanol, just engine, turbo, and chassis. From there they get into why the trucks making the biggest peak horsepower numbers on the dyno are not always the ones winning at the track, and why second gen Cummins trucks keep running away with it the same way they have been dominating UCC. That leads into camshaft talk. Overlap, intake valve closing events, and how RPM range should dictate cam selection, and why a cam that makes huge peak numbers can actually bleed off boost and lose power down the track. The conversation then shifts to cylinder heads, covering valve sizing, port flow, and why a factory piston might outperform a forged piston at this power level. There is also a quick detour into transmission durability, since the top two finishers in this class are both running stock automatics, plus a reminder that this is not a high dollar class. Anybody with an engineering mindset can be competitive here. They close out talking about the next Fast 72 event in Texas this September, with a purse north of one hundred forty thousand dollars on the line for the season finale. If you are into diesel performance, Cummins builds, or smart engineering beating raw horsepower, hit subscribe on YouTube and follow the show on your favorite podcast platform. Everything the guys talked about when it comes to cams, cylinder heads, and turbo limited builds is the kind of work Power Driven Diesel lives in every day. Head over to PowerDriven.com to check out the full catalog and get your own build dialed in. Shop Power Driven Diesel: https://www.powerdriven.com 0:00 Intro to Fast 72 racing class 0:38 Turbo limited rules: no nitrous, water, or methanol injection 1:42 Why peak horsepower doesn't always win races 3:04 Second gen Cummins trucks dominating the field 4:02 Engine size and camshaft talk begins 10:04 Camshaft overlap and boost bleed off theory 12:05 Big cams making peak power but losing at the track 14:21 Torque management in a turbo limited class 14:27 Upcoming Texas race and the $150,000 purse 15:37 Factory pistons versus forged pistons at this power level 16:58 Survival over flow: lessons from Top Fuel cylinder heads 19:04 Stage two power division head breakdown 20:55 Cam shift points and RPM range analysis 21:22 Intake valve opening and closing event theory 24:00 Cold start versus high RPM valve timing tradeoffs 31:06 Cylinder head valve sizing and port flow 36:56 Why stock sized valves are holding up fine 42:09 Bearing and rod loads in a turbo limited build 44:57 Building a street and race second gen Cummins 46:36 Why this class rewards engineering over budget 49:32 Stock automatics versus manuals surviving the power 51:36 Recap on prize money and where the class is headed 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