Stern lift w/ nosecone
 

Seeing CQ's thread reminded me of something else I wanted to solicit feedback on. Does anyone here with a smaller v hull think or experienced stern lift with the addition of a nosecone?

Brad, were you referring to my post on getting more bow lift? I put a nose cone on an early Bravo, 89 model with the blunt face. The nose cone did cut my top speed because of the stern lift. If I could get the bow up I think my top speed would be better. I got the stern out of the water some, now I need to get the bow up so the whole boat has less wetted surface. Prior to adding the nose cone I need to drag some tab at cruise and WOT to prevent porpoise. With the nose cone I only need tab to level the ride out at all speeds. Cruise speed of 40 to 45 and WOT near 70. Force 235 about 4500 lbs. loaded on the water. It all comes down to what your particular hull needs.

Tim T.

I was more wondering if some here (like you) did notice stern lift with a cone. I would have thought that at positive trim, the oposite might happen. Ever since putting one on my boat, It feels like I have additional stern lift.

Brad,

I have no exact way to measure amount of stern lift or bow lift. I have put over a thousand hours on this hull and several engines and drives in all conditions imaginable. You got it though, I felt that stern lift is what the nose cone did. After that much seat time you just know the boat. I thought that with the stern up and positive trim it should get the bow up but the prop just can't hold that much leverage. Now the hook needs to come out. I think this will do it for me. Budman has the same hull and about the same power. His nose is planted as well. BAJA most likely did not intend these hulls to run at those speeds often so the hook was put in to satisfy the masses. I think removal of the hook will solve the problem

Tim T.

The thing is that I never felt this behavior when running similar speeds without the cone. Many have now told me that a cone is not needed in the later cases. They say that factory classes do not run them and are running in the 90s. I was always under the past impression that high 80s was where the case would blowout. Maybe I read blowout into it, when I should have interpreted it as increased ineffeciency. One question might be, has anyone here actually experienced blowout with the late model bravo gearcase without a cone, and at what speed? I ran it into the mid 80s with no ill effects. Now the boat almost has a bow steer tendency at speed. :eek:

Brad,
That is discouraging.. to make a change and go backwards. What brand of cone is it anyway? I know years ago a friend tried one brand and it made the stern dig in real bad. He went to another brand it is worked great.. Good bow lift and no tendancy towards ill effects. I had the same setup.. but it was an older drive. At about 78mph it quit. Would not go faster, nose cone let me break the sound barrier.. Well sort of..
Check around to see what kinds of cones people are runing with your hull.. that may help..

Good luck..

Dick

Brad, you need to try some props. I have recently had very good experiences with a hydromotive quad 4. Compared to a Bravo 1 prop it takes less trim to get the bow up. I know 3 blade props are generally faster than 4 and 5 blade props, but I think you would be better off with a 4 blade with your HP and speed potential. I think the bow running down is actually incouraging. What you need to do now is find a prop to snatch the whole boat up and then you will be runnin and the glued in feeling will be gone. I think a 28 quad 4 is a great place to start. I ended up with a blueprinted 27 that I turn around 6200 for a top end of 96.9 MPH. That is a little over 8 % slip!!! My Spinelli 29 at 6300 is a top end of 97.8. 15.2 % slip??? Both props carry the bow low but the Whole boat is level and out of the water. You'll get there!!;)

Yeah, you're right, I need to spend some time with other props. I am encouraged to hear of your results with the hydro. I'll try one.

Brad,
If the nose cone was put on incorrectly or the nose cone is not a parabolic type then you will have more stern lift. The nose cone adds to the running surface of the boat and creates more lift.
The parabolic shaped nose cone is shaped like an upsidedown airfoil and counter acts the additional lift it could create.