How much faster is a imco lower?
 

At the same length what do you think is faster a Imco style sport master case lower or a standard bravo low water pick up style.

If I remember right if you are above 85 the imco is faster...below 85 the standard bravo is faster.

In a 30' straight vee at 90 MPH the twin IMCO lowers we were about +4 MPH at the same X as the Bravo I lowers. Not sure you could expect these results in the 60- 70 MPH range....didn't measure.

This is a loaded question.

What hull? What length hull? Steps?

Also I would think props might come into play here as well as what might work great for the Bravo might not be the best prop for the Imco. Like KA said other things come into play here on top of.

I have a standard length imco lower I would be willing to sell if interested. Pm for details

I have a 34 phantom with stock bravo,s with the little shafts and run over 90mph. the x is high allready If the 1 inch shortys dont work I was going to install a 1 inch spacer because the Imco has a large shaft and it I think would be a faster style case.

Go for it Tom. I'm doing the same on my Talon in the fall when I get bored. Converting from small to fatshaft sportys. Maybe hull water pickups and see if I can raise the drives above 1 5/8" above hull bottom also. Setup is where all the fun is! Congrats again on new ride. Run it like your stealin it!

Its all hydrodynamics. 85-90 is the most a stock bravo will work efficiently as far as I know. Over that the water becomes aerated over the prop. Call Wilson , He'll tell you. But bare in mind he is trying to sell you too, as is everyone in So Fla.

I added the Imco SC lowers for the reasons mentioned above, I kept the same depth(1"spacers on standard length). My boat is having trouble getting on plane now. I can't for the life of me figure it out. Next will ne a prop swap. I switched lowers to get reduce prop slip on the top end and now I have it on the low end.