endeavour32

iTrader: (4)

Does anyone have any experience with Imco Shorty drives on the Formula SR-1 hulls? I'm thinking about replacing my current lowers if I can see some gains out of it. Plus I'm getting ready to send BBlades my props to have worked, but it doesn't make any sense to do that if I'm going to switch to shorty drives. So anyone know of anyone that has made this change and the results from it?

My boat is an '89 292 Formula
Engines: 450hp ea
Current speed: 68 MPH

sprink58

I talked to a few people in the know about this...including Tommy Hoffstetter. If you can get the X Dimension raised about 2" or more on these boats and get the prop center above the point where the plane of the bottom disturbs the water around the prop you will see increases in top speed.

Notice how Fountains have that recessed area of the transom near the same elevation that the props run? There is a reason for that.

I have been told by more than a few experts that 5-10 mph can be gained with just the change you are describing. Based on that I would estimate that 75 would be possible with the Imco Shorties on your boat.

BenPerfected

+2" on an 1989 with a Bravos might be aggressive. My thought is to call Brett and see what his experience has been on this hull. A higher X with 5 blades might be the ticket. You will likely be giving up bow lift with the high X but this may be able to be offset with the right props. Where are your prop shafts now?

Rattlesnake Jake

iTrader: (2)

FWIW. I tried 2'' Shorties on a 1993 336 with 3 different props. Ran best with 24 Bravo 1s but created so much stern lift that lost some top end. Also fuel consumption was very noticeable. Prop guy said right set of 5 blades will correct problem and only cost around 3K.

endeavour32

iTrader: (4)

Thanks for the info guys. I'll see what Brett has to say when I talk to him next.