Rapture prop?

[Last Nerve]

I have a 1999 Sea Pro 255WA with a Mercruiser 5.7<br />and an Alpha 1 Gen 2 outdrive. Boat is new to me<br />but seems to be lacking RPM's at WOT. Boat weight<br />is about 6000 lbs loaded with full fuel tank. <br /><br />I am currently running a 17P x 14-1/2 Vengeance.<br />RPM's at WOT not more than 4200. I was wondering<br />if changing to a Rapture 15P x 14-1/4 would help.

 

[studlymandingo]

Re: Rapture prop?

I'm not a prop expert, one of the prop guys will be along soon to help, but a 5.7l with a 17 pitch should be blowing the needle off of the RPM gauge. You may have some other issues at hand.

 

[Texasmark]

Re: Rapture prop?

The big boys will jump in here and rescue me, but when you change prop types, you introduce a new variable. Now if you wanted to talk about changing this and that with the same critter ok; but in changing critterws, all bets are off.<br /><br />Sorry BTTWITI.<br /><br />Mark

 

[walleyehed]

Re: Rapture prop?

This would be better suited to your application.....<br />http://www.iboats.com/mall/propfinder/index.cgi?manufacturer=Mercruiser&rotation=Standard&search=Product&chart=78&pitch=17.00&prop_chart_relation_id=11839&**********=984598684&engi ne_id=449&pf_new=1<br />Call iboats and ask for a Solas Lexor, P/N 1571-155-15...for some reason it's not listed but I know it exists because I have one. The link is to show the prop which is a 17P, not the 15, and this prop really performs on heavy boats.<br />You would be very disappointed with the rapture on that heavy rig..this is where diameter (max) can make a world of difference on a sterndrive.

 

[captnpgn]

Re: Rapture prop?

So, Kenny can a prop of the Lexors dia. be equally beneficial to other stern drives almost half the weight of Last Nerve's, in the 3200# range with the same engine? If so, is it the dia. alone that gives optimum performance with this prop. or do other characteristics come into play that makes it suitable over other props. of like dia.? Thanks for sharing your expertice. It's been helpful to all.

 

[Last Nerve]

Re: Rapture prop?

Thanks for the suggestion Kenny. My main concern is getting more RPM's<br />at WOT to prevent lugging.<br /><br />When trimmed properly I get 40 MPH (gps) @ 4200 RPM.<br />Boat is quick to plane and I haven't had any performance problems.<br /> Is a 15 pitch prop common in similar set-ups?

 

[walleyehed]

Re: Rapture prop?

Last Nerve, that's alota boat and with a 5.7, yea, 15P is not uncommon at all. <br />To answer both of your questions, yes, the Lexor produces alot of thrust on rigs that would be using a merc mirage or vengeance. The Lexor has huge blade area and is cupped to bite hard, not just TO the tip, but around it as well. You'll get an RPM gain without loosing all your speed.<br />The small blade area of the Rapture will decrease hole-shot and likely cost a bit more speed than the Lexor will, as it's (Rapture) design is better suited to lighter outboard applications.

 

[captnpgn]

Re: Rapture prop?

Would a Lexor 17p prop give Last Nerve the increased RPM he needs?

 

[walleyehed]

Re: Rapture prop?

No, he's going to need the 15 in the Lexor. The 17 would likely result in a slight drop in RPM due to the fact it has shown to produce a lower slip ratio than the Vengeance, possibly due to larger blade area.