Prop Help
 

Since I installed the new drives on my boat, I've been having problems getting on plane. The new drives are XR uppers and 1" shorty IMCO lowers. I have three set of props I've been working with:

P5 X 27P
P5 X 29P
Bravo 1 4 Blade 30P

With the shorter X dimension none of the above worked very well. The 5 blades were a joke getting out of the hole and the 4 blades were not much better. So, we decided to put the IMCO spacers on to get the drives back down to the previous height I was running with the stock Bravo 1's - thinking that this would solve the problem. Unfortunatly, it did not help, except that the 4 blades worked a bit better getting on plane. But, they are still not that great. Even now with the drive spacers and the 4 blades it still takes about 20-30 seconds to get out of the hole - and the 5 blades are even worse.
So, I was hoping someone could give me an idea of what other 4 blade I might be able to try out that will get me out of the hole better.
Also, I am running 1.5 ratio drives behind Gellner built 500 EFI's. It's my understanding that max throttle these motors should be spinning no more than 5500 rpms. Right now at full throttle I am seeing 5000 revs max and 80mph on the GPS. I really don't care much about top speed, I just wanna be able to get out of the hole quicker. Perhaps that's not possible, but I thought I might post here and see what you guys think. For what it's worth, I ran a prop slip calculation, and with the 29P 4 blade, at 5000 rpms running 80mph I am at 13% slip.
Any thoughts or suggestions would be greatly appreciated.

PS - Anyone looking for a good deal on 5 blades, I posted them in the classifieds:

http://www.offshoreonlyclassifieds.c...o23107-en.html

Are you running K-planes?

Were the 5blade props ever reworked? Are you trying a variety throttle and tab positions

Strange that with the spacers, you didn't get back to the original ability to plane. Even with the gear case design difference.

We can supply you with Maximus props for testing. They have additional diameter and blade area that can help planning.

Let us know if you want to give them a try.

No, the tabs I have are part of the special edition Playboy dress Cig gave the boat when they made it. I believe they are shorter than K-planes....they are thick billet aluminum tabs. Here's a pic:

That is one of the purdy Black one's ain't it. Cool! That should be plenty of planes to get you up. I'll leave the rest to Brett.

Thanks for the reply, Brett, I was hoping you'd chime in...
I agree, I was a bit amazed the spacers didn't help much...but, they didn't take much off the top end so I'm pretty sure they less hydrodynamic drag from the nose cone is the culprit; be it good or bad.
Anyway, to answer your question....Yes, I have tried a variety of throttle and tab positions. Throttle position and imput doesn't seem to yield any solid results though. From idle if I ease into it, the props will bite nicely right up until about 2000 rpms and then they loose all contact and totally wash out - both 4 and 5 blades...
Tabs are a bit more responsive and yield better results. But, as you know, it's all trial and error. Too much tab and it's like a anchor...to little and they aren't effective....raising them too early and you kill your momentum. I can't say I've tried every possible tab/throttle setting simply becasue I haven't been able to use the boat as much as I'd like - hence the reason for my questions here. But, the 4 blades are by far and away MUCH better out of the hole than the either set of 5 blades. Also, I prefer to run the 4 blades just to limit the amount of stress on the drives.