Boatmad.com


Reply
 
Thread Tools Display Modes
 
Old 29-10-2007, 02:17 AM   #1
Registered User
 
RossM's Avatar
 
Boat make: Phantom 23

Join Date: Mar 2006
Posts: 1,650
Send a message via MSN to RossM
P20 setup

What prop would you reccomend for a p20 with a 200 blue printed xr2 on a detwiler lifter?
tried the yam drag prop off The Mutz Nuts and it was quicker and diddnt really notice it struggling,
soo was thinking 26 chopper as theres one avalable
do you think 26 would be a good pitch to use?
what should the engine spin to?
Not really been seeing more than 6100 with the laser 2 (23") and that was 64 mph on gps i think, was a while back so cant really remember!
thing is the yam pulled the same revs but it was 5 mph quick (also had an extra 2 people in the boat so not a direct comparison)

Also when pulling a skier the engine really bogs down and struggles to pull the skier out, once boat and skier up on plane its fine

Cheers guys
__________________

RossM is offline   Reply With Quote
Old 29-10-2007, 01:08 PM   #2
Registered User
 
Burty's Avatar
 
Country: UK
Location: Weston Super Mare
Occupation: Electrical Engineer

Join Date: Mar 2004
Location: Weston Super Mare
Posts: 6,351
Send a message via AIM to Burty
A small one, what gearbox ratio is it?
if 1.87:1 then i would say a 21" as you really want the revs in the high 6's to use all of the 200hp
__________________

Burty is offline   Reply With Quote
Old 29-10-2007, 02:27 PM   #3
Registered User
 
RossM's Avatar
 
Boat make: Phantom 23

Join Date: Mar 2006
Posts: 1,650
Send a message via MSN to RossM
Cheers for that Rob,
yep think its a 1.87
what u recon then 22 chopper?
RossM is offline   Reply With Quote
Old 30-10-2007, 09:22 AM   #4
Registered User
 
The Docta's Avatar
 
Country: UK
Location: Coventry (but from Lee on Solent)
Occupation: Sales Director
Interests: My Boat of course
Boat make: Extreme 21
Engines: Merc V8
Cruising area: Solent

Join Date: Jul 2005
Location: Coventry (but from Lee on Solent)
Posts: 578
thats what I run on my R21 with 200 xr2. Probably not the fastest possible combo but works well for me and hole shot is still good 4 skiing etc

__________________
The Docta
The Docta is offline   Reply With Quote
Old 30-10-2007, 09:41 AM   #5
Registered User
 
Country: England
Location: South West
Occupation: Development engineer
Interests: Fast boats
Boat name: Xtreme
Boat make: Bernico 21
Engines: Mercury F1, 300 Drag, XR2 "Fingerported"
Cruising area: South West

Join Date: Mar 2004
Location: South West
Posts: 1,043
21.5" ET or Chopper

21.5" ET or a chopper if your brave.

You should be reving the motor to 7000-7500 with no problems at all.
Proping the boat like this will enable you to still have good hole shot, plenty of mid range grunt if for example you have the bow tank full, and will still acheive a good top end speed.

I ran 73.9mph (gps speed not pub speed) with a 22" chopper that had been worked (serveral times). this was a bit of a hand full and my old P20 was set up very well with very little chime walk.

You will need to try lots of different props to find what suits, but be prepared to have some worked to really suit your application.

For best all round drivability I used a 22" Laser 11 small hub worked down to a 21.5" thined out blades with some cupping added, used to run very level with no bite as the boat re-entered the water and no chime walk.

I still have this prop if you get stuck, it's not for sale but you may try it.

Cyco
Cyco is offline   Reply With Quote
Old 30-10-2007, 11:55 PM   #6
Registered User
 
RossM's Avatar
 
Boat make: Phantom 23

Join Date: Mar 2006
Posts: 1,650
Send a message via MSN to RossM
Cheers fellas, I will speak to my uncle (whos boat it is) and see what he wants to do,

does anyone know of a et for sale then? other than burtys hooky one
RossM is offline   Reply With Quote
Old 01-11-2007, 10:29 PM   #7
Registered User
 
gazza's Avatar
 
Occupation: Champion Pie Eater
Boat name: On The Rocks
Boat make: Ring 21 marshan 17 four winns horizon, hydro 3 pointer, f2 cat, backdraft 22
Cruising area: Way up norf and Sarf coast areas

Join Date: Apr 2007
Posts: 1,618
Question

Quote:
Originally Posted by Burty View Post
A small one, what gearbox ratio is it?
if 1.87:1 then i would say a 21" as you really want the revs in the high 6's to use all of the 200hp
Rob
I understood 2 litre blocks run 2.1 box and 2.4 2.5 blocks run 1.87.
but there again i've been wrong before.
I just remember helping out building boxes up my friends, a main dealer marine engineer many years ago.
Gaz
gazza is offline   Reply With Quote
Old 01-11-2007, 11:12 PM   #8
Registered User
 
Country: England
Location: South West
Occupation: Development engineer
Interests: Fast boats
Boat name: Xtreme
Boat make: Bernico 21
Engines: Mercury F1, 300 Drag, XR2 "Fingerported"
Cruising area: South West

Join Date: Mar 2004
Location: South West
Posts: 1,043
Quote:
Originally Posted by gazza View Post
Rob
I understood 2 litre blocks run 2.1 box and 2.4 2.5 blocks run 1.87.
but there again i've been wrong before.
I just remember helping out building boxes up my friends, a main dealer marine engineer many years ago.
Gaz

Most XR2's came out of the factory with a 1.87:1 box.
Ski racers generally used the 1.87:1 box
OCR racers generally used the 2.1 box

Rob is probabaly not best to answer this as he has never run an XR2 or a 2.0
What difference does the gear ratio make tho? you just prop to suit!

Do you have a point to your statement?
Cyco is offline   Reply With Quote
Old 01-11-2007, 11:27 PM   #9
Registered User
 
gazza's Avatar
 
Occupation: Champion Pie Eater
Boat name: On The Rocks
Boat make: Ring 21 marshan 17 four winns horizon, hydro 3 pointer, f2 cat, backdraft 22
Cruising area: Way up norf and Sarf coast areas

Join Date: Apr 2007
Posts: 1,618
Quote:
Originally Posted by Cyco View Post
Most XR2's came out of the factory with a 1.87:1 box.
Ski racers generally used the 1.87:1 box
OCR racers generally used the 2.1 box

Rob is probabaly not best to answer this as he has never run an XR2 or a 2.0
What difference does the gear ratio make tho? you just prop to suit!

Do you have a point to your statement?
Well actually i do have a point to the statment, it may seem i am wrong with the ratio, but Rob is only trying to say which prop may be more suited because unless you have bucket loads money or have access to a range of props, an educated guess with as much info should put you in the right ball park figure for which pitch to go for.
So whizz kid you can answer the exact prop question because i dont see you listing which pitch to go for,
gazza is offline   Reply With Quote
Old 02-11-2007, 09:34 AM   #10
Registered User
 
Burty's Avatar
 
Country: UK
Location: Weston Super Mare
Occupation: Electrical Engineer

Join Date: Mar 2004
Location: Weston Super Mare
Posts: 6,351
Send a message via AIM to Burty
Quote:
Originally Posted by gazza View Post
So whizz kid you can answer the exact prop question because i dont see you listing which pitch to go for,


Quote:
Originally Posted by Cyco View Post
21.5" ET or a chopper if your brave.

You should be reving the motor to 7000-7500 with no problems at all.
Proping the boat like this will enable you to still have good hole shot, plenty of mid range grunt if for example you have the bow tank full, and will still acheive a good top end speed.

I ran 73.9mph (gps speed not pub speed) with a 22" chopper that had been worked (serveral times). this was a bit of a hand full and my old P20 was set up very well with very little chime walk.

You will need to try lots of different props to find what suits, but be prepared to have some worked to really suit your application.

For best all round drivability I used a 22" Laser 11 small hub worked down to a 21.5" thined out blades with some cupping added, used to run very level with no bite as the boat re-entered the water and no chime walk.

I still have this prop if you get stuck, it's not for sale but you may try it.

Cyco
Burty is offline   Reply With Quote
Old 02-11-2007, 01:43 PM   #11
Registered User
 
Country: England
Location: South West
Occupation: Development engineer
Interests: Fast boats
Boat name: Xtreme
Boat make: Bernico 21
Engines: Mercury F1, 300 Drag, XR2 "Fingerported"
Cruising area: South West

Join Date: Mar 2004
Location: South West
Posts: 1,043
Doohh!!

Quote:
Originally Posted by Burty View Post
What do you need the boat to do?
ultimate top speed and not too much concern for hole shot or good alround performance maybe pulling a skiier now and then?

For ultimate top end always go with a chopper.....but you have to be a good driver or very brave!!
Pitch depends on the boat set up and weight and what gear ratio you are running. The pitches I have listed are for use with a 1.87:1 gear set.

For alround performance either the ET or a laser 11 small hub.
Some mates have tried and swear by Trophy 4 blade altho I have never seen the top end results myself.

And as said before let the motor rev to at least 7000rpm.


The Whizz kid
Cyco is offline   Reply With Quote
Old 02-11-2007, 02:26 PM   #12
Ash
Registered User
 
Ash's Avatar
 

Join Date: Feb 2007
Posts: 33
.. can somone please explain what 'hole shot' is

Ta
Ash is offline   Reply With Quote
Old 02-11-2007, 02:34 PM   #13
Registered User
 
Country: England
Location: South West
Occupation: Development engineer
Interests: Fast boats
Boat name: Xtreme
Boat make: Bernico 21
Engines: Mercury F1, 300 Drag, XR2 "Fingerported"
Cruising area: South West

Join Date: Mar 2004
Location: South West
Posts: 1,043
Hole shot

Quote:
Originally Posted by Ash View Post
.. can somone please explain what 'hole shot' is

Ta
Pull away.......how quick you can get 'out the hole'.
Cyco is offline   Reply With Quote
Old 02-11-2007, 03:37 PM   #14
Registered User
 
The Docta's Avatar
 
Country: UK
Location: Coventry (but from Lee on Solent)
Occupation: Sales Director
Interests: My Boat of course
Boat make: Extreme 21
Engines: Merc V8
Cruising area: Solent

Join Date: Jul 2005
Location: Coventry (but from Lee on Solent)
Posts: 578
Well I im a 15st lump and I can still get up on my skiis with my worked 22 chopper spinning on a 200 Xr2. Also I wouldnt say that I was Fabio Buzzi but have no reall problems controlling my boat at flat out.

Dont think you have to be that brave to run a chopper? Just sensible!



Ive also heard from a v reliable source that its a raker (worked 24??) you want for max speed and controll on a Phantom with XR2
__________________
The Docta
The Docta is offline   Reply With Quote
Old 02-11-2007, 03:52 PM   #15
Registered User
 
Carl's Avatar
 
Location: hayling island
Boat name: snow monkey
Boat make: extreme 24
Engines: mercruiser 6.2

Join Date: May 2004
Location: hayling island
Posts: 2,072
on my p 20 with an xr2 1.87 box,and no lifter i ran a laser 11 22",boat was quick and very stable.
Carl is offline   Reply With Quote
Old 02-11-2007, 09:52 PM   #16
Registered User
 
Country: England
Location: South West
Occupation: Development engineer
Interests: Fast boats
Boat name: Xtreme
Boat make: Bernico 21
Engines: Mercury F1, 300 Drag, XR2 "Fingerported"
Cruising area: South West

Join Date: Mar 2004
Location: South West
Posts: 1,043
Quote:
Originally Posted by The Docta View Post
Well I im a 15st lump and I can still get up on my skiis with my worked 22 chopper spinning on a 200 Xr2. Also I wouldnt say that I was Fabio Buzzi but have no reall problems controlling my boat at flat out.

Dont think you have to be that brave to run a chopper? Just sensible!



Ive also heard from a v reliable source that its a raker (worked 24??) you want for max speed and controll on a Phantom with XR2

What hull?
What speed is flat out?
Cyco is offline   Reply With Quote
Old 02-11-2007, 09:54 PM   #17
Registered User
 
Country: England
Location: South West
Occupation: Development engineer
Interests: Fast boats
Boat name: Xtreme
Boat make: Bernico 21
Engines: Mercury F1, 300 Drag, XR2 "Fingerported"
Cruising area: South West

Join Date: Mar 2004
Location: South West
Posts: 1,043
Quote:
Originally Posted by Cyco View Post
What hull?
What speed is flat out?
Ok just read your advatar, a 21 ring is not quite the same as a P20!!
You have alot more beam and weight to start with.

Also you mention 'ski's' as in a pair, the pull up required for 2 ski's is nothing of that required to pull out a mono skier.

I would guess that your top speed is about 63-65mph??
Cyco is offline   Reply With Quote
Old 02-11-2007, 11:10 PM   #18
Registered User
 
The Docta's Avatar
 
Country: UK
Location: Coventry (but from Lee on Solent)
Occupation: Sales Director
Interests: My Boat of course
Boat make: Extreme 21
Engines: Merc V8
Cruising area: Solent

Join Date: Jul 2005
Location: Coventry (but from Lee on Solent)
Posts: 578
Yeah - thats about right mate. Pleanty quick enough for me though.

7.5k! Now thats what I call brave

Surely if a R21 is heavier but the hole shot is fine for skiing and a bit of wakeboarding, then it should be even better on a lighter P20?

Incidentally, my props a worked small ear chopper. Are they a bit less forgiving than the big ear choppers??
__________________
The Docta
The Docta is offline   Reply With Quote
Old 13-01-2008, 08:36 PM   #19
C4-STORM
 
brett duke's Avatar
 
Country: England
Location: Portsmouth
Occupation: Company Director
Boat name: Claygate/The Jester
Boat make: Cougar Sport Racer 27/Extreme 21
Engines: Honda BF225/Mercruiser 5.0 V8
Cruising area: Solent

Join Date: Jul 2006
Location: Portsmouth
Posts: 77
Quote:
Originally Posted by The Docta View Post
Well I im a 15st lump and I can still get up on my skiis with my worked 22 chopper spinning on a 200 Xr2. Also I wouldnt say that I was Fabio Buzzi but have no reall problems controlling my boat at flat out.

Dont think you have to be that brave to run a chopper? Just sensible!



Ive also heard from a v reliable source that its a raker (worked 24??) you want for max speed and controll on a Phantom with XR2
Mmmm I remember the last time you attempted to ski!!
__________________

brett duke is offline   Reply With Quote
Reply

Thread Tools
Display Modes

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 Off
Pingbacks are Off
Refbacks are Off


Powered by vBadvanced CMPS v3.2.3

All times are GMT +1. The time now is 07:01 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
×