29' Fountain prop slip
05-05-2020, 01:25 PM
#11
That gets it to 18.5% which is still on the higher side, but your top speed seems about normal. People sometimes get too hung up on slip%. My 28 Pantera had similar slip % numbers. The higher slip will help keep the drive alive too. I would bet a 1/2-1 inch drive spacer would help you also. I increased my drive spacer on my Pantera by and inch and slip numbers dropped some. I picked up about 3-4mph at cruise speed and 1-2mph on the top end and it carried the bow better.
05-05-2020, 02:52 PM
#12
Registered
Think a hydro motive Q-IV is 15 1/2”
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Petrocanada (05-05-2020)
05-05-2020, 03:03 PM
#13
05-18-2020, 10:49 AM
#14
Offshoreonly Advertiser
Offshoreonly Advertiser
The 28 Bravo 1 is only 27 pitch. This makes the slip % at 15.5%. Not a great number but certainly acceptable.
I would consider the 1/2" spacer.
Our 4-SPEED props are very efficient and reduce slip numbers. With a decrease in slip comes the consumption of more HP and a decrease in WOT rpm.
Mid to upper 20's for slip % at cruise with your hull is not uncommon. Slip is always higher at cruise as the boat is more wetted. There is give and take with Labbing. Top speed Labbing does not help cruise. We Lab each propeller specific to goals. We do not do one size recipe fits all.
Many shops do and many do not understand the adjustments to create the determine outcome.
Brett
I would consider the 1/2" spacer.
Our 4-SPEED props are very efficient and reduce slip numbers. With a decrease in slip comes the consumption of more HP and a decrease in WOT rpm.
Mid to upper 20's for slip % at cruise with your hull is not uncommon. Slip is always higher at cruise as the boat is more wetted. There is give and take with Labbing. Top speed Labbing does not help cruise. We Lab each propeller specific to goals. We do not do one size recipe fits all.
Many shops do and many do not understand the adjustments to create the determine outcome.
Brett
__________________
Brett Anderson / BBLADES Professional Propellers
920-295-4435 http://www.bblades.com/
[email protected]
Brett Anderson / BBLADES Professional Propellers
920-295-4435 http://www.bblades.com/
[email protected]
05-18-2020, 11:42 AM
#15
Thanks Brett,
I’m going to give you a call regarding some 4-speed and 5-speed testers.
i think i want to focus on cruise more than top speed.
Id like to cruise at less RPM and greater speed if I could
I understand 5 blade is better for this option. I could be wrong.....
I’m going to give you a call regarding some 4-speed and 5-speed testers.
i think i want to focus on cruise more than top speed.
Id like to cruise at less RPM and greater speed if I could
I understand 5 blade is better for this option. I could be wrong.....
