Need Prop Input
 

I Have A 30 Ft Single Step With A Merc 575sc Xr Drive With The Its System. Im Usiing A Non Labbed Bravo 26 Pitch And At Wot Its At 4900 Rpm And About 72 Mph. I Want To Get A New Prop To Gain Mph But I Dont Know Much About This Topic So Any Input Will Help. Thanks In Advance

Re: Need Prop Input
 

Sounds like a little tuning on your prop is all you may need. How's the boat ride with it now? 30" single step, single drive...Hmmm... Name that hull.

Re: Need Prop Input
 

i agree with FASTER though, work with the prop you have now, you arent that far off of where you need to be. contact Throttle Up or someone local to you that knows what they are doing.

Re: Need Prop Input
 

It is a Kachina hull

Re: Need Prop Input
 

The 575 sc needs to run at about 5300 RPM at WOT. So you need 400 RPM, which really is a lot of RPM but possible. You could consider down pitching your prop down inch and labbing for about 200-250 RPM. OR the alternative to labbing would be to look at a 24P Bravo I stock and possibly needing a few small adjustments after base lining.

Julie

Re: Need Prop Input
 

I would Lab the prop you have. If the prop is true box stock, we should see 5200rpm. This is a great rpm for your engine. Mercury states 4800 to 5200 recommended range. The rev limiter is set at 5400. We prop to 5100-5300 on set ups depending on the needs.

I wouldn't go to the 24 Bravo 1. You will gain rpm but not speed. Also you will lose cruise speed! Your slip is 8%, that's great! Lab the 26.

Re: Need Prop Input
 

Hey thanks both BBlade and throttle up for your help i'll do some tinkering and let you know how it turns out.

Re: Need Prop Input
 

selfmade:
I have a similar setup to yours (575/28 Nordic Heat), and have great results with a Hydromotive P5-X. I also agree that you should try to turn as many RPMs as possible, just below the limiter. With a supercharged motor, boost comes with RPM, and HP and torque come with boost.
Steve