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twisted mentality 08-17-2007 10:08 PM

Need help with prop slippage
 
What is the correct procedeure to use to cure prop slippage? Mine is at 22% right now. I don't know if I need a shorty drive or if I need the drive deeper in the water. I have a 29 scarab with a single 502.

DMOORE 08-17-2007 10:28 PM

I would talk to one of the pros about the prop you are using. There are many "tricks" available during the labbing process to help with this. Possibly a prop change also. I'm sure BBlades or Throttle up can help.



Darrell.

Griff 08-18-2007 03:22 AM

IMO, bigger single engine boats have higher propslip in most cases. I lowered my drive 1" on my Pantera and it reduced propslip by about 5%. It also depends on what prop you are running. Props can also be tweaked to lower slip.

Wild Card 09 08-18-2007 07:23 AM

Well how about starting by giving a little bit more info.i take it we are talking about a stock 415hp 502?
Prop, top speed, revs, speed at which this slip value is reached, slip value at cruise (3500 rpm), drive, nose cone, drive ratio, propshaft to hull bottom dimension?
A high slip number is not neccessarily bad, but to decide where to change you need to know where you are!

MOBILEMERCMAN 08-18-2007 11:18 AM

Like Wild Cars 09 said, high slip is not so bad, You cannot compare low slip numbers on cats and twins to singles. What is more important is speed. Some set ups have high slip and high speeds with big pitch props. Slip is a measurable variable to help find speed.
Speed is the important number.
Jim

twisted mentality 08-20-2007 09:04 PM

Engine is a procharged 510 dynoed at 680hp with less than 5lbs of boost. Drive is a bravo1 with a 27 labbed b1 1.5 gears with a wpm nose cone. speed is 73 at 5400 rpm,but was having some problems with motor so wasn't running to full potential.

Wild Card 09 08-21-2007 02:12 AM

Well if you are seeing 5400 rpm(and the motor is not yet running to its full potential, as you said) then you are running too little pitch, for a start.

Nose cone reduces slip, and you have one. Mid ninetees Scarab wonŽt have a crazy high x dimension.

IŽd go up to a 28 or a 30 bravo and try an unlabbed 26 and 28 if possible.

First though, get the motor to run reliably at the designated WOT.


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