First a little about the application. I am on a team that builds and compete's with open wheel race-cars in the Formula SAE program. I am helping to build the engine and would like to know what the very knowledgeable people here thought was the best way to get HP out of a CBR 600F4i motor with a 20mm restrictor right after the throttle body. The restrictor is a key part of the problem. We also dont have much money to spend on custom parts.

 

is that a motorcycle engine? how many cylinder?

 

any other constraints other then the the plate?? damn 20mm that shiet is tiny!!

 

Pump in some nitrous after the restrictor. No one will beat you in the straight away.

 

im in the SAE program too, its a lot of a LOT of work, good luck!

it makes building huge horsepower hondas a no-brainer.

 

I would suggest building the intake manifold around the restrictor plate. So you can keep your intake velocity, and have better volumetric efficiency.

meaning, if you have a 20mm restrictor plate, make the intake runners 20mm, so it's like the whole intake manifiold is one big restrictor.