Worried
 

I want to put this out to all you prop guru's:
I am now worried about the durability of my IMCO SC drive.

I have an 09 Nordic Heat with a 600sci that I have been doing prop and spacer testing for the last 6 months. Below is the table of my results. These are real slip numbers. Tach has been verified with a digital tach, and speeds with my analog GPS, my digital GPS and a radar gun.

The current best prop is a Hering 26 pitch, 5 blade bravo style prop. Slip is coming in at 5.2%

I am not the first Nordic Heat to post such low slip numbers. The Illmore 700 Heat regularly posts numbers between 6%-8% with the same drive and hull.

For you doubters:
Prop= 26 pitch Hering 5 blade bravo style prop
Speed= 83.8 mph
RPM= 5400rpm -- On the rev limiter

I am about to upgrade my 600hp motor to aproximately 750+hp using some upgrades offered by Whipple for my motor.

What I am worried about is that 750+hp and 5.2% slip on a 28 foot boat, sounds like a recipe for a broken drive.

What do you think??
Should I switch back to a 4 blade prop for reliability sake?
How much horsepower is safe in front of the IMCO SC drive?

I would like to hear some opinions.

Chris