Very disappointed with my 347 dyno!

[Rev]

Somethings definitely wrong here. Horsepower is a function of torque at various RPM's. If the dyno can't measure torque, then I don't see how it can measure horsepower. I'll bet if you try adifferent dyno, you'll get better data. Unless the slicks were spinning on the rollers, that shouldn't matter much. Weight of the wheels/tires might affect the outcome, but that would be a reflection of driveline efficiency. I'd put on some street tires and try a different dyno facility. There should be no legitimate reason why the dyno would not show torque. At least that's my reasoning.

Rev