Go Back  Offshoreonly.com > Technical > Prop Talk
Prop suggestions??? >

Prop suggestions???

Notices

Prop suggestions???

Old 08-03-2008, 10:04 AM
  #1  
Registered
Thread Starter
 
razor1115's Avatar
 
Join Date: Jan 2002
Location: Peoria, IL
Posts: 320
Likes: 0
Received 0 Likes on 0 Posts
Default Prop suggestions???

Guys,

Have the lucky "opportunity" to select new props due to losing a prop shaft and prop running over the weekend in our river. Anyone have some first hand knowledge, not just a give this a try opinion?

Here's the scoop on the set-up:

1999 35' Fountain
HP500s warmed slightly ~590-600hp
Bravo drives with -2" Bravo SHop shorties
Was spinning 30P Bravos labbed by BBlades

Perf was:
Fall, cool weather [email protected] gps
Hot, humid summer ~5-5100rpm@76-78ish

Looking to get slip numbers down as they seem pretty high. Also open to buying/labbing a set of props rather than replacing the 30P Bravo LH I lost in the river. If Bravos seem to be the ticket from everyones consensus, guess I will need to get on the horn to BBlades and get a matched set...

Also, Hydros usually came on these boats... any sense in going back that direction? I believe I have seen a lot of discussion on P5's and P5X's... any comments there?

Thanks for all the great suggestions and great knowledge on this site!

razor1115
razor1115 is offline  
Old 08-03-2008, 11:06 PM
  #2  
Registered
 
Join Date: Jan 2004
Location: Northern NY
Posts: 5,325
Likes: 0
Received 112 Likes on 44 Posts
Default

Something is off here, my 99 35 with stock 500 carbs ran a solid 80 any day and a best of 82-83 in perfect conditions on a cool day, with stock 26 Hydro Quad 4s or the Merc lab 28 Bravos, standard lowers at the original X dimension. If you are in fact making close to 600 hp you should easily be high 80s or maybe even close to 90 mph.

The Hydros were my favorites for handling in rough water and at speed, the Bravos were good cruisers and worked better at low speeds and on plane. Both sets ran essentially the same speed on any given day.

Last edited by RaggedEdge; 08-03-2008 at 11:12 PM.
RaggedEdge is offline  
Old 08-04-2008, 12:00 AM
  #3  
Registered
 
Rebel_Heart's Avatar
 
Join Date: Feb 2004
Location: LOTO
Posts: 1,173
Likes: 0
Received 0 Likes on 0 Posts
Default

My P5Xs seem to be a good prop on the 35 with raised x-dim. When I purchased my props from Tom at Hydromotive, he said unless the x-dim was extremely high that I should stay with the P5Xs. So, I really don't have an info on the P5s.
Rebel_Heart is offline  
Old 08-04-2008, 07:13 AM
  #4  
Registered
Thread Starter
 
razor1115's Avatar
 
Join Date: Jan 2002
Location: Peoria, IL
Posts: 320
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by RaggedEdge
Something is off here, my 99 35 with stock 500 carbs ran a solid 80 any day and a best of 82-83 in perfect conditions on a cool day, with stock 26 Hydro Quad 4s or the Merc lab 28 Bravos, standard lowers at the original X dimension. If you are in fact making close to 600 hp you should easily be high 80s or maybe even close to 90 mph.

The Hydros were my favorites for handling in rough water and at speed, the Bravos were good cruisers and worked better at low speeds and on plane. Both sets ran essentially the same speed on any given day.
Ragged,

Are those gps speeds? I didn't think I was off at all. The all- stock boat specs at 77-80 mph, I believe. Throw in another ~60hp = +3 mph (a stock hp500 is rated at the prop, so they realisitically put out 530-540 hp at the crank) and raise the x-dim = +1-2 mph. That puts me at +4-5 mph over stock.

That said, puts the boat at 81-82 on it's worst day (from the 77 mph spec) and 84-85 mph on its best.

I know the prop efficiency could be better. Am I missing something?

razor1115
razor1115 is offline  
Old 08-04-2008, 07:43 AM
  #5  
Registered
 
Join Date: Jan 2004
Location: Northern NY
Posts: 5,325
Likes: 0
Received 112 Likes on 44 Posts
Default

Originally Posted by razor1115
Ragged,

Are those gps speeds? I didn't think I was off at all. The all- stock boat specs at 77-80 mph, I believe. Throw in another ~60hp = +3 mph (a stock hp500 is rated at the prop, so they realisitically put out 530-540 hp at the crank) and raise the x-dim = +1-2 mph. That puts me at +4-5 mph over stock.

That said, puts the boat at 81-82 on it's worst day (from the 77 mph spec) and 84-85 mph on its best.

I know the prop efficiency could be better. Am I missing something?

razor1115

More or less, no GPS speedo on the boat but based on numbers from a friends boat when side by side, so the numbers are pretty accurate.

The HP 500s were 500 hp at the crank and 470 hp at the prop per Merc. So I would assume your hp would be 90-100 more than that on either end. Using the 20 hp per mph general rule would put you into the numbers I mention. And the short lowers on a 99 model should add a couple more. To make the 600 hp from the base 500 you most often do heads, cam, and better exhaust. You didn't mention what was done to perk yours up.
RaggedEdge is offline  
Old 08-04-2008, 01:58 PM
  #6  
Registered
Thread Starter
 
razor1115's Avatar
 
Join Date: Jan 2002
Location: Peoria, IL
Posts: 320
Likes: 0
Received 0 Likes on 0 Posts
Default

The engines were gone through at the time of the Crane valve spring update (a problem everyone has heard about) The only thing that wasn't swapped was the exhaust.

Dyno sheets show 620hp at 5400 rpm before they start dropping off. That said, timing was dialed back from 36deg to 34 by installer before me (I verified) That probably cost 25-30hp. So now were at 590hp. Throw on stock exhaust and forgot we probably lost another 20hp.

That leaves a net of ~570ish - another 10hp for accessories = 560hp. That's how I arrived at the +60hp over stock hp500 (@ the crank). Does that seem realistic? It would be awesome to get to 90mph, however.

Suppose a new exhaust might pick up a couple mph... and a more efficient prop.

razor
razor1115 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
25 OUTLAW
Baja
2
08-10-2007 11:08 AM
dtsquest
Powerquest
4
03-10-2005 06:46 AM
NJThumper
General Q & A
3
07-14-2004 10:51 PM
THRILLSEEKER
General Q & A
1
10-02-2002 03:12 PM
NEVRENUFF
General Q & A
10
07-09-2002 01:50 PM

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: Prop suggestions???


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.