Is there a way to "Detune" an HP500 without doing any "major" mechanical changes? Thanks in advance.

I have a 454 Mag MPI that I will trade you for the HP500. No hassle detune!

I gotta ask WHY??? HP500's are near bullet proof.

If you must, probably the easiest would be to take out some timing. Go from 36 to like 30...... Then maybe put on a throttle stop

LOL Dave M

Detune an HP500? Is this to keep a new driver out of trouble? Throttle stop or change the leverage of the throttle controls so that "full throttle" is Not. But you can't limit the throttle so much that the secondaries don't open...lean not good.

Maybe you could put a restrictor plate under the carb.
But again why? What do you want to detune? Less HP or less TQ or less rpm?
How about an air-gap manifold and you might knock off a bit of HP but would probably gain some TQ.

The reason is because a race team I know would like to fit into a class. He is way too slow for P4 but is too fast for P5..... He would like to race P5 because it is his first year racing.

The reason is because a race team I know would like to fit into a class. He is way too slow for P4 but is too fast for P5..... He would like to race P5 because it is his first year racing.

The reason is because a race team I know would like to fit into a class. He is way too slow for P4 but is too fast for P5..... He would like to race P5 because it is his first year racing.

Maybe pitch down in prop a few sizes or change gear ratio...the acceleration off the corners would be wicked....

Yea, What he said.
That is what most racers do.
Prop the boat for the max speed for the class.