OK guys, here's where I'm at right now... (crossroads I guess)

Boat: 1997 Active Thunder (no notch)
1.5:1 Bravo XZ drives with no nose cones or spacers
Prop shaft to bottom of the boat distance = 6"
540ci - NA engines around 700hp
Target RPM range for engines is 5600+ rpm

With 2 guys in the boat on near full tanks on a flat river:
1. 28p stock Bravo I's - 5600rpm @ 83mph GPS - 18% slip
2. 32p stock Bravo I's - 5100rpm @83 mph GPS - 19% slip

Btw, I have run several times with 5 people this summer 82 mph on 3/4-full tanks with both the 32 B1 and 28 B1s. So I really am hitting a wall.

I've heard a lot of guys say that the 4-6" propshaft to transom dimension is pretty common.

Pat, - with my propshaft currently at 6" below the transom, would a 2" imco shorty help significantly while still working with a Bravo I style prop? Is that still conservative, or would I be looking at 5 blades to get on plane?

Here's what I'm thinking, I need to get prop slip down first... (I could run with less fuel and never let anyone ride with me again... but there are alternatives :) )

1. I need labbed props... but don't know what one yet because my slip is too high. (Too much drag)
2. I could try a nose cone, if I do, I may still be too conservative in the X-dimension to gain the most out of my situation.
3. IMCO shorty...???? I'd get to 4" on the prop shaft dimension to the transom and would have a better bullet... the nose cone is much more efficient.

Any advice you guys have would be much appreciated!!!

where's the 30's??
 

I was just wondering what happened to the 30p prop test numbers? I would think a labbed set of 30's with the sportmaster shorties will get you to 87 @ 5400-5500, just a guess. slip approx. 15%???

Tibb, personally I like option 3 for you. No notch, normal drive height for driveability, etc. I believe that your boat would respond well to shortys. But, I don't have practical experience with them. Try posting a question in the tech section. Call BBlades props and Throttleup for opinions.

BTW I think now that you have accurate data on slip, speed, rpm that you have taken the first step in getting your numbers up to where you want them.

Thanks for your opinions!

I have not tried 30's - the reason being that I have so much drag that the 28's are getting me to the RPM's I need.

My feeling is that when I change to a nose cone/shorty - I should reduce my slip enough to start getting closer to running a labbed 32 - (like a stock 30) - I should be able to run a labbed 30 right now and get enough RPM's. Once I reduce the drag, I should be able to pick up RPM's just from breaking free a little more.

Any one else have opinions on the prop shaft height? How conservative would 4" below the transom be? Right now, that's about all I can get without major changes... if I'm not gaining a lot, then I should stay at 6" and just do nose cones.

Helicopter scared the crap out of me at TPA but neat pic. Should've plucked my eyebrows. :D

Another.

BTW clark crb76 was about 800 yards off my port bow when these were taken. I was trying to catch him to get an old/new thunder combo pic. However, Clark was running some kind of super cruising props that produced 65 mph at 1500 rpm and I couldn't catch him in time. Stared at his azz all day. :D :D

Yea right!!!

Wife just said you have a nice azz! You must've made an impression. :cool: