Go Back  Offshoreonly.com > Technical > Prop Talk
Need Prop Input >

Need Prop Input

Notices

Need Prop Input

Old 03-13-2006, 07:06 PM
  #1  
Registered
Thread Starter
 
Join Date: Mar 2006
Posts: 16
Likes: 0
Received 0 Likes on 0 Posts
Default 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
selfmade is offline  
Old 03-13-2006, 09:51 PM
  #2  
Registered
 
FASTERDAMITT's Avatar
 
Join Date: Jun 2002
Posts: 2,001
Received 2 Likes on 2 Posts
Default 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.
FASTERDAMITT is offline  
Old 03-13-2006, 10:16 PM
  #3  
Registered
 
Join Date: Oct 2005
Location: Oshvegas WI
Posts: 520
Likes: 0
Received 1 Like on 1 Post
Default 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.
JUKED YOU is offline  
Old 03-14-2006, 02:25 AM
  #4  
Registered
Thread Starter
 
Join Date: Mar 2006
Posts: 16
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Need Prop Input

It is a Kachina hull
selfmade is offline  
Old 03-14-2006, 07:47 AM
  #5  
Registered
 
throttleup's Avatar
 
Join Date: Mar 2002
Location: Cajun Country
Posts: 5,143
Likes: 0
Received 1 Like on 1 Post
Default 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
throttleup is offline  
Old 03-14-2006, 08:52 AM
  #6  
Offshoreonly Advertiser
Offshoreonly Advertiser
 
bbladesprops's Avatar
 
Join Date: Jun 2003
Location: Princeton, Wisconsin
Posts: 3,875
Received 46 Likes on 13 Posts
Smile 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.
__________________
Brett Anderson / BBLADES Professional Propellers
920-295-4435 http://www.bblades.com/
[email protected]
bbladesprops is offline  
Old 03-14-2006, 01:36 PM
  #7  
Registered
Thread Starter
 
Join Date: Mar 2006
Posts: 16
Likes: 0
Received 0 Likes on 0 Posts
Default 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.
selfmade is offline  
Old 03-14-2006, 08:46 PM
  #8  
Registered
 
Steve Zuckerman's Avatar
 
Join Date: Nov 2002
Location: Nashvegas, TN
Posts: 2,621
Likes: 0
Received 1 Like on 1 Post
Default 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
Steve Zuckerman is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
TSPM
General Boating Discussion
15
02-02-2008 10:23 AM
FormulaOne
Formula
9
07-28-2006 06:29 AM
klaw
General Q & A
0
03-29-2005 09:23 AM
GLH
General Boating Discussion
29
10-08-2004 11:16 AM
lhousman
General Q & A
6
03-10-2002 08:16 AM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Quick Reply: Need Prop Input


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.