What is the max trim level on a Bravo drive?

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08-08-2002 | 12:42 PM

#11

Steamin Rice

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From: Cave Creek, AZ

Quote:

Originally posted by Mbam
The limit is actually supposed to be before the 2 thrust areas on the front of the drive are no longer supported by the gimbal ring. That is way too high for my taste. Most indicator cables have 3" of travel, so #8 would reperesent that much trim at the cylinder. Take a look and see where the drive sits when on #8. If you actually need this much trim for max speed there are a number of things you could optimize. If you post your max speed, RPM, drive ratio, prop pitch and style I will see if I can offer any hints. Also what kind of boat?

Marc,

Thanks for the info. I took at look at it last night and the mechanical indicator is set up so that when it's maxed out at 8, the front of the drive is still supported by the gimbal ring by about an inch or so. Based on the feedback on the board, it sounds like I can safely trim to this level without worrying about damaging the drive. This is actually the same thing that the boat builder told me, but I wanted to be sure.

The boat is a 2002 29' Shockwave and I have a stock 24P BravoI prop with 1.5 gears. The motor is an HP500EFI and the drive is a BravoI XR with the ITS. So far my max speed on GPS is about 68 MPH at 5000 RPM, which I think works out to around 12% slip. I will probably get the prop labbed over the winter to pick up a couple of hundred RPM.

I really haven't spent much time trying to optimize the setup, but if you have some suggestions for things to experiment with I may give them a try. I'm pretty happy with the overall performance of the boat as-is, but if there are some fairly simple things that I can try I'll give it a shot...

08-09-2002 | 12:32 AM

#12

mcollinstn

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From: tn

If you have only trimmed to "6" and the bhoat continues to get more "aired out" and faster, then go ahead and trim higher to see if the speed increase continues. Usually, your prop will begin to lose bite and you will begin to slow a bit.

08-11-2002 | 10:50 AM

#13

Steamin Rice

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From: Cave Creek, AZ

Quote:

Originally posted by mcollinstn
If you have only trimmed to "6" and the bhoat continues to get more "aired out" and faster, then go ahead and trim higher to see if the speed increase continues. Usually, your prop will begin to lose bite and you will begin to slow a bit.

That's the plan...I just wanted to verify that I wasn't going to exceed the max trim on the drive before givingit more trim...I'd hate to over-trim trying to find max speed and then break my drive. After looking at it closer, I still have more to go.... Thanks all for the info..