Prop testing : looking for opinions
07-26-2002, 12:06 PM
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Prop testing : looking for opinions
I'm thinking of moving up in pitch to bring my RPM's down and hopefully gain some MPH.
My current set up is a labbed 26 Bravo one spinning thru a 1:5 gear ratio. My RPM's are 5600-5700 and I have run a best of 80.7 on GPS.
I wonder if I will gain anything by switching to a 28 Bravo one ?
My current set up is a labbed 26 Bravo one spinning thru a 1:5 gear ratio. My RPM's are 5600-5700 and I have run a best of 80.7 on GPS.
I wonder if I will gain anything by switching to a 28 Bravo one ?
07-26-2002, 12:09 PM
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ya up 2 pitch sounds right, your rpms sound a bit high.
is this 28 gonna be labbed?
if not you might have even speeds....
labbed is a different story, let the pros comment on this.......
I'm going to post a topic on props right now for my boat...
is this 28 gonna be labbed?
if not you might have even speeds....
labbed is a different story, let the pros comment on this.......
I'm going to post a topic on props right now for my boat...
07-26-2002, 12:53 PM
#3
26Scarab,
If you're sucessful in moving up in pitch, and wanting to sell the B1-26, let me know.
80.7 is moving pretty good for a 26 Scarab, you must have some impressive power!!!!!
Jon
If you're sucessful in moving up in pitch, and wanting to sell the B1-26, let me know.
80.7 is moving pretty good for a 26 Scarab, you must have some impressive power!!!!!
Jon
07-26-2002, 01:51 PM
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Jon,
I will let you know. The prop is in pretty decent shape, there are a couple of nicks in it though.
Yes I have a N/A 540 roughly around 675HP.
I will let you know. The prop is in pretty decent shape, there are a couple of nicks in it though.
Yes I have a N/A 540 roughly around 675HP.
07-26-2002, 02:17 PM
#5
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26scarab,
You NEED a 28P prop!!!
I think you'll gain about 3 to 5 mph.
You NEED a 28P prop!!!
I think you'll gain about 3 to 5 mph.
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BillR
'00 Scarab Sport 302 CC
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BillR
'00 Scarab Sport 302 CC
'02 Cigarette Top Gun TS
'02 PQ 340
'00 PQ 280
'98 Scarab 22
'97 Baja Outlaw 20
'72 Checkmate
'65 Glastron
07-26-2002, 04:13 PM
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You might want to try a Hydromotive 27 as well. I have a friend who is running in the nineties with that hull who believes that it runs best (and most stable) with some stern lift.
07-26-2002, 04:53 PM
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I remember you have oval port heads on that motor which may mean you have big torque in the lower RPM range. I think as you increase in pitch your "seat of the pants" acceleration will be less and you may pick up some speed. I would maybe even try a 30 Bravo and see how it does. If the torque is high enough in the 5000 RPM range you may be pleasantly surprised that your motor will not lug down as much as expected when the larger pitch props are run. This could result in some significant gains. If your motor is set up for high RPM then the larger props will lug her down to much and the speed won't be there. Keep us posted on your results and good luck with your testing!
07-27-2002, 06:35 PM
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Well I tested it last night...not very good results.
It did plan very good but I made to passes.
1st pass had a max of 4800rpms and a speed of 73.4
2nd pass 5000rpms and a speed of 75.9.
I guess the 26 stays .
Laster,
I've tried a Hydro before and it was too much stern lift , the boat was pretty squirrely.
I'd like to talk to your friend, how much power does he have to get into the 90's ?
It did plan very good but I made to passes.
1st pass had a max of 4800rpms and a speed of 73.4
2nd pass 5000rpms and a speed of 75.9.
I guess the 26 stays .
Laster,
I've tried a Hydro before and it was too much stern lift , the boat was pretty squirrely.
I'd like to talk to your friend, how much power does he have to get into the 90's ?
