I have a stepped bottom 42' Fountain with #6 surface drives . What kind of prop slip numbers are being seen with , this set up or ones like it

The answer to this question has levels of answers after some questions.
X dimension, prop size, CG etc. as well as load affect the outcome.
A general answer is under 15%. Some people may think it should be much lower but that isn't always reality.
What is your current speed, rpm at WOT? Also what is your gear ratio?
We can then discuss the results.
If you are in the 10%-12% range you are perfect.

Brett

The X has been -1 1/2" from the factory, just dropped it to -1" . At speeds over 100 I was seeing an 18% slip . Boat feels like it needs more bite , running a 6 blade prop already .

notd1 1So you are a touch high. I might need to run your performance numbers.
We offer BBLADES built spacer plates for #6 drive applications.
We also have a test program for these plates to try for a fee rather than buying.
Here is a link to the program. Let me know how we can help. It makes sense to give us a call.

http://bblades.com/6-spacer-plate-test-program/

Brett

Brett