Wake 101
Home   Articles   Pics/Video   Gear   Wake 101   Events   Community   Forums   Classifieds   Contests   Shop   Search
WakeWorld Home
Email Password
Go Back   WakeWorld > >> Boats, Accessories & Tow Vehicles Archive > Archive through June 08, 2008

Thread Tools Display Modes
Old     (jhgsupra)      Join Date: Mar 2006       05-28-2008, 10:40 AM Reply   
Can someone explain the dis/advantages of prop cup? I'm looking at an OJ # 466 (14.25x14 1 1/8 .090 cup) vs. an OJ #475 (14.25x14.5 1 1/8 .120 cup). I realize the #466 will pull a bit harder out of the hole due to the "14" but what effect does the cup size have? I run a Supra SSV with about 2000# of ballast. I'm sure either will work fine however I would just like to know. Thanks...
Old     (denverd1)      Join Date: May 2004       05-28-2008, 1:02 PM Reply   
top end. IIRC the 475 have a few or mph's than the 466. B/c of the .5" of pitch and bigger cup. something about the cup spinning water off the prop giving it more pull at high RPMs?

Karl, line 1...
Old     (roverjohn)      Join Date: Dec 2007       05-28-2008, 1:10 PM Reply   
In general( non cavitating props) cup acts like pitch. So, more cup is the same as more pitch. There is almost no disadvantages to cup unless prop rpm starts getting very high or you spend an inordinate amount of time in reverse and in fact more modern prop designs are 'cupped' over the entire blade and therefor don't appear to have a cupped edge.
Old     (boarditup)      Join Date: Jan 2004       05-28-2008, 1:19 PM Reply   
Cup works while the prop is spinning at high speeds, but not low speeds. You can cup a prop up to about .150 on a 14" pitch prop without getting to the point of limited returns. So, if you have a prop that has low pitch for hole-shot and a lot of cup (.090-.150) you have a prop for the best of both worlds. At very high rpms (5,000+) cup loses its effectiveness. That is why the drag boat props are not cupped - they use rake (the difference between the pitch of the blade at the hub and the tip) to move water outward to the larger blade area. Our props use some rake, but not to the degree of the very high speed props.

To answer your question directly, either prop will do. The 475 will have a top end advantage of 2-3 mph but will accelerate to 30 mph about a second slower.
Old     (jhgsupra)      Join Date: Mar 2006       05-29-2008, 3:26 AM Reply   
Thanks guys. Exactly what I was looking for.


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 On

All times are GMT -7. The time now is 10:29 PM.

Home   Articles   Pics/Video   Gear   Wake 101   Events   Community   Forums   Classifieds   Contests   Shop   Search
Wake World Home


© 2019 eWake, Inc.    
Advertise    |    Contact    |    Terms of Use    |    Privacy Policy    |    Report Abuse    |    Conduct    |    About Us