Too many changes at once
 

So I may have made too many changes and am working backwards to figure out where we went wrong. So I ran best with 32s with -2 but the stern lift was crazy. It ran fastest 95 normally with both tanks full and 5 adults.
We thought let's get rid of some of the stern lift and that should help. BBLADES added rake and cup and removed the diffusion ring thinking the flare on the ring was contributing to the lift. I could not get on plane at all. We put 1" spacers in and got on plane with some cavitation until it came over, acceleration was amazing and it had great bow lift but topped out at 90 MPH and too much RPM 5700 to 5800 slip was 20%. We sent props back put the diffusion rings back on went to 17% slip still running 90 mph at 5500. After talking to Brett today we are gonna try spinning the props in. I know I've seen a bit of talk about it but little in the way of a definitive answer. Trying to get some speed back by reducing slip and keeping RPM. Thoughts?

So the answer is that is definitely part of the answer. Full of fuel and a solid 92 no more porpoise and handled better. Bow lift was great and slip down to 15% a bit more work to do but that is a great start. I noticed no difference in dock handling.

this may be a stupid question but how do you determine stern lift?. how does it feel? are you saying the boat porpoises at high speed?

i dont think there are any Sabers running props in. fwiw

i'm currently running Hill props 26 pitch with 1.35 ratio drives. it seems to me the boat feels rock solid at i run up to top speed, i need the drives trimmed to about 8 plus on the indicators (3 is neutral) to get to top speed.

When I say stern lift you can actually feel it and see it. I get more bow steer, you can feel more of a wake, and it almost feels like you are driving downhill. From another boat or shore the stern actually looks equal or higher than the bow. I can't speak for others but it completely changed the drive and feel. Spinning in, the whole boat is more out of the water. The bow is up and not much stern at all in the water on top end. It feels a little loose but in a good way. Skips over wakes and waves without any steer, picked up speed at same RPM and even my wife said it felt better. None of the low speed porpoise, or that wake jumping feel. Never had porpoise at high speed. It would tend to catch air though. Mine has never liked trim over 6.5 it would lose speed and begin to slip. As far as no others spinning in Doug said he thought mostly the same. I'm not arguing with success it may be something others want to try!

hmmm... mine doesnt due any of that. at higher speeds, mine trims out nicely , the bow feels light without feeling loose.

i have Hill props, unmodified. they spin out.

have you checked the bottom?

mine didnt change the ride when i switched to -2 lowers.

my ride improved with my -2s I agree it is probably a prop problem. I went to Bravo 32 4 blades and started having the stern lift problem. We have made multiple adjustments to fix that, I still had lost some speed and didn't like my slip numbers. Turning in was an experiment that I'm really pleased with. I can see someone who is not used to driving loose would find it uncomfortable. I'm very comfortable with it. It is like having a big power single.

I talked with Hill, which prop are you running. I sent you a PM. Give me a call.

yes, I have checked the bottom, obviously this boat has been around many years. We have made may changes to drive train etc. It's just dialing it in and getting some last bugs out. Probably to start over again just when you think you got it. Spinning is is losing some of it's desired effects as the boat lightens from less fuel. I will say it is a toss up at this point

I’m still surprised that people use/like the 4 blade Bravos on a twin 28. I tried them and despised them for everything other than getting on plane. Went from 7-8% slip on 3 blades to 18% on Bravos, granted at a lot less HP and no shorties.

They don't make a 3 blade big enough that I am aware of.