Pat McPherson

I have a 1997 24' Superboat.
23' 7" Long, 7' Wide, 24° V Bottom with no steps or pad.
She weighs about 3500lbs dry.
Power is a 415HP/502MagMPI through a 1.5 ratio Bravo drive.

I'm currently running a Stock 28p RH Bravo I prop.
Top speed is 75mph (GPS) @4800rpm and at 3000rpm the speed is about 45...

Before I repowered last year, my boat had a 310HP/7.4MPI.
I ran both a 25p Mirage plus and a 26p Bravo one.
With the Mirage plus, she ran 65-66 @ 4500rpm.
With the 26p Bravo, 63-64 @ 4400rpm.
I had my 26p Bravo I labbed and got to the same 66mph as the Mirage plus.
BUT, this took three attempts at "labbing" before I saw the 2mph gain...

I have run my labbed 26p Bravo with the new power and the engine over revs. What I have noticed though is that I can trim higher with the labbed prop before it starts slipping. I also believe that the labbed prop carries the bow a little better.

I have thought about trying a 5 blade but I'm not going to spend the big $$ for one at this point.
The Bravo I seems to work well. Should I have someone try to make it work better???

Downtown42

My guess is you will go to 5000rpms (where you want to be at anyway) and be at 77-78.

Pat McPherson

That would be worth it...

crb76

I show that you have about 12% slip. Thats pretty good. If you lab the 28 you will get 200 more rpm but your slip should increase about 2% to 14%. You will only get about a 1 mile an hour. Talk to Bblades he was at Mercury Racing before starting his own shop and he may have another suggestion for you on props and then tell you if you should or shouldn't lab them. He helped me gain 4mph by going to a REV 4 over the Bravo 1 and we are now labbing for 300 RPM and another 2.5MPH.

Pat McPherson

1 mph would not be worth the effort, if I would see 2-3mph then yes.
I would like to try a REV 4 but think they stop at 25p. My boat would likely need a 27p.
Thanks for the response...

throttleup

It's difficult to say ow much of a speed gain you will see with lab finishing. The reason is unless a baseline prop is used it's very difficult to quantify speed gains or decreases.

If accurate testing is done a typical gain is about 2-3 mph. It may take a couple times to get it just right but that's all part of getting a boat dialed in just right.

When we lab finish we will do adjustments at no charge. The goal is to get your boat dialed in to your style of boating.

If you have any questions give us a call. We are out of the shop until Monday, we are in Key West supporting the race teams at the races.

Matt

Pat McPherson

I'm looking for a slightly used 28p Bravo 1 RH to have labbed.
Anyone got a deal?

throttleup

I have just recieved RH Bravo I Merc Lab Finished propeller from a client who wishes to sel it. It is in great shape.

Julie
Throttle Up Propellers
727-531-2255

Pat McPherson

Thanks Julie, but I'd rather start with a stock prop and have it altered to my specific needs...

Monkey Spanker

You picked up 11 mph with 100 hpr?? What else did you do?