Velocity Tom

Has anyone swapped standard length bravoe,s out for 1 in shorty imco,s. Did you need to go to a 5 blade? My 388 with 500's leaps on plane even without any tabs so I think it should be ok. The 30 pitch merc. racing 4 blades are not enough now so I figured I would go to a 5 blade any way. I do have a set of Halls full race 4 blade 32's that should be just right. But would the 5 blade be faster ?

Tinkerer

I would not go to 5 blade props unless you have no choice. Less blades is more efficient. 5 blade props are harder on the drive also. It is a different world but my boat ( Daytona ) didn't like 5 blades. I couldn't get on plane with 4 blades so I adjusted the drive for more negative trim. I can now get on plane with the 4 blade prop and have good slip #s. ( 11 % from 4000 up to 6000 ) When I bought my SCARAB 34 it came with 25 pitch 3 blade Mirage props and would blow out unless you eased it up on plane. I installed 4 blades and the boat got on plane like a jet boat. NO slip at all. Later I increased my HP from 385 to 650 and ended up changing to IMCO -2 shorties and 28 pitch Bravo props. It would slip but not blow out when getting on plane.