Next season I'm looking at running a class with a power/weight limit. I was thinking of doing this with a camshaft, but what about an intake restrictor plate?

Will a restrictor plate just cut upper RPM HP or would it effect HP through out the RPM range? I'd like to keep the lower torque and HP intact and just be able to tune the Maximum HP with a restrictor plate if possible.

 

Bump - Anyone know?

 

is there a rule on what you can and cant do to make the power limit? If you can, why not just pull a bunch of timing?

 

I have heard that it will only limit max power, yes. I have no personal experience though.

 

It limits the air coming in to the engine, therefore limiting power across the board. There are ways around this limited air, ie:a restrictor specific camshaft, that will still make great power, but less air = less power. Generaly a restrictor plate is used on carb's, ALMS racing use trumpet style intakes.

Like on the drayson car, the restrictor's are the two little round pieces on the roof. They are always the begining of the intake tract, atleast all the ones I have made are.

 

Going into NASA ST-1? I agree with Jensen that the restrictor should be 1st in line for air intake, but to my knowledge decreases across the board. You could definitely play the tuning game with a smaller (or specially ground) cam and pull some timing.

SCCA has a formula on how they figure out the size for restrictors they put on cars, but I don't recall if they have shared what that formula is or not. Wouldn't hurt to call and ask around.