Looking at possibly picking up an IMCO drive. How much extra power does it take to spin these vs. a non modified Bravo?

Which Imco drive are you refering to? They say there is some extra power needed for the XR gears, but I have not experimented with that situation to tell you first hand. Depending on which Imco your looking at, they could have XR gears and some do not. I have a couple of broken Imco gears that never had any real power applied to them, but they were the regular Merc gears that they did their magic to and they lasted 12hrs.
A standard XR drive is suppose to cost you a few mph, which could relate to maybe 20-30 hp. I want to see that for myself, but that is what I have heard.
Good luck

Dick

xr drive is 1.8 miles per hour slower then an xz drive.

why because the xr drive has stright cut gears were the xz has beveled gears.

so ask if your getting straight cut gears or beveled and that will answer your question.

Treadwell

Thank you for qualifying that Treadwell..

What about the new Quad 4 I think it is called from IMCO. The one with the extra gear on top. Interesting set up but I would think it would take more HP to turn.

Once I heard the testimonial statement of a fellow board member, that Imco said to him, "what part of no warranty don't you understand?" They'll probably never see my $.

It's one thing to say, I'm unable to warranty your parts because,.... but to be so cocky about it, man that make my blood boil.

DAVE

I have the new IMCO 4x4 and it appears to be bullet proof, It shifts like a dream, and I cant see any loss of power when comparing it to the same boat as mine, same engine with a B-MAX drive, mine is actually faster.

Thanks for the info. Yea I bet it shifts great. Never have liked the cone clutch set up on Bravos. Now all they need to do is set it up with a 2 speed and I think they may be on to something!!

Treadwell,

If the XR are 1.8 mph slower than the XZ gears, wouldn't there be a lot of heat in the drives? Depending on the boat, it usually takes anywhere from 15 - 25 hp to increase the speed by 1 mph, that would would be 30 - 45 hp loss in the gears, wouldn't that generate a lot of heat? On my boat, I changed from a regular Bravo to a XR drives without any speed loss.

What have other people seen that have changed from Bravo to XR?

Then there is Pulse Drive... Gain a few extra MPH and something that has a 5 year warranty that doesn't break. Hell, you don't have to even throttle off the waves...

Mongo