HARDCORE A/O

Hi all. I had started a thread last year on this but didn't follow up because I blew my motor and have been working on the boat since. I finally got it running again and on Sunday I made the fastest run ever @ 121mph. This was with a bone stock Bravo 1 32 pitch and a 1.34 gear.
Also, it was with neutral trim during the first part of the run but I have to admit that it accelerated so hard and felt like it wanted to lift the bow and I touched the trim in a bit. I was only in the throttle for about a 1/2 mile and I eased the throttle back when the rpms started to climb into the mid 6000rpm range. Truthfully, I'm not sure exactly what slip I'm getting now but experience with this prop on this boat tells me its around 15%. I can't say exactly what the Rpms were because I don't have a recall on the tach as yet.
My guess is that I need a 5 blade in about 34 pitch to get more stern/overall lift as I think the boat is capable of running in the upper 120's. The motor is a 540 with a M-3 procharger @ 10lbs of boost making an estimated 1000+ hp.

throttleup

What is the rotation of your propellers?

Julie

bbladesprops

I'm assuming this is a single engine. Therefore rotation isn't a concern but listing could be. Also, I doubt there is any problems there since you ran it 120.

Was it stable?

What rpm do you want to turn the engine?

Fast boat!

throttleup

Thanks Brett.....I stared right at it and missed it...2600! Anyway, from prior testing experiences with Hydro 5B props we were not successful with them on your hull. We did have great success with the twins though. I would agree with Brett on behavioral issues though being of concern.

Julie

bbladesprops

Hey Julie, NP, we are only human. LOL

Hope all is well down south!

Brett

throttleup

Ahh...just another terrible day in paradise! lol

Julie

HARDCORE A/O

Hey Guys, Thanks for the interest. I really believe this boat has a lot more left in it.
The drive is a stock (!!! I know!) XR upper and the Lower is an Imco 2" shorter Extreme w/ large propshaft. There is no setback box. The rotation is right hand and the helm is on the starbrd side. I didn't have a listing problem during the run probably because I had my brother in the passenger seat (both of us are like 250lbs too!) It all happened so fast once the motor got on the boost that it was hard to drive, look at gauges etc. and pay attention to the handling but it seems to be handling ok except when I trimmed it in a bit (like 2 degrees neg.) at the end of the run and it started squirreling a bit (at like between 115 and 121!). However, the prop feels like it was lifting the bow at nuetral trim and that's why I lost nerve and trimmed it in.
I sure I can run more prop though because it was pulling like a SOB over 6000 RPM and would have probably hit the limiter at 6600 if I hadn't backed off. I figure the motor is making well over 1,000fwhp.
I've run cleaper and cleaver style props on this boat before, albeit at a much slower speed, but this hull doesn't like either type of prop. I was thinking about a Hydromotive P5-X but they only make a 31 pitch, and quite frankly, I have had bad experience with their props, one on this boat that threw a blade off acuople yares ago and another on a different boat.
It looks like my choices are:
labbed 34 pitch B-1, labbed Maximus or those new piece of CNC art that Throttle-up is producing. I think that since this boat is running so good, I might eventually buy one of each of those, do you guys think it would be worth my while to start wh a labbed 34 B-1 or would the extra stern lift of a five blade be better at those speeds? Thanks again for you help.

HARDCORE A/O

Julie:
Which type of Hydromotive 5 blade props are you refering to? Did you test the "X" series as well on my type of hull. I know from experience that my hull doesn't like the "cleaper" style (QX?) Hydro 4 blade. But I'm sure I've read posts on here previously where people were running the P5-X on like 25' Eliminators (similar hull to mine) with good results. I'm interested in more stern lift to get the boat to level off more with more overall lift which I think is crucial at these speeds. Obviously, the PX-5 might not be an option for me since they only (I think) make up to 31" pitch, so I'll be looking at a labbed Maximus or a Throttle-up CNC prop if the 5 blade is the way to go. Like I said, ultimately, I'd like to get one of each, but I want to order one now so I can do some more testing without putting the motor on the limiter.
If the 5 blade isn't the way to go, what would you guys recommend? A labbed B-1 34" with diffuser cut off, etc.? Do you carry "labbed" B-1 props in stock or do you do them per order?
BTW: To answer Brett's earlier question: I think I'd like to keep the RPMs below 6200 max.
Thanks for your input.

throttleup

YEs we tested a P5-X on the AO. But the guy who tested it did not like the stern lift so he stuck with the Bravo I. He said the 5B gave it to much stern lift. But remember that blade count is dependant upon drive heigth and the owners conveyed desires. Some people just do not like a loose boat...and as we know loose is fast! I would recommend that you try around ear 5B propeller and if you still think you need more stern lift then we'll set you up in a CNC propeller! All of our labbed props are made to order if you ultimately land on the Bravo I propeller. Try to do some testing if you can and let us know.

Julie