422 dyno fail

roccodart440 said

My last engine, which at that time made 467hp / 514tq at the crank. I put it on a chassis dyno that said 314hp / 550tq.

Dyno's are weird. I dyno my engines to break them in safely and tune them. I also like to make changes and see what differences occur. The numbers are just for ego and social media likes. I've put many cars on the trailer that made a lot more HP than mine.

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I just got my 340 powered car back from the shop after a chassis dyno tune. It made 258 hp and 293 lbs torque. (air temp was 90* and 41% humidity) I was a bit disappointed at those numbers but the shop owner did a good job of explaining how much actual loss occurs between "crank HP" numbers and "real world" numbers to the rear wheels. He said that he's seen a lot of deflated egos from customers who thought their "mega" engine should be producing more HP after seeing the chassis dyno results. He went on to say that the "15% " loss on a chassis dyno is a myth and that the actual percentage can be much higher.