I have a 1996 wellcraft thunder 38. The claimed weight of the boat is 10,200 lbs...but, I have added blowers, transmissions, and speedmaster 4 drives, so I am sure she is a bit heavier than she was with standard equipment. I am trying to figure out where to go next on props. I set the prop shaft at 1.5 inches below the hull when I hung them. It is currently running a 28P, 17.5 diameter 4 blade clever.

I have tried everything under the sun for good planing, currently best i have found is a gentle roll in to 4500 rpm tabs down and it still takes a good while.(tried every configuration and trick i know or have heard.)

Yesterday with 3 people and about 100 gallons of fuel

3500 rpm was 49 on GPS
4500 rpm was 70 on GPS

Is that enough enougfor anyone to make an educated guess on where to go from there? The extended plane time sucks, but I'll deal with a crappy plane for a good cruise number and high top end.

Any thoughts?

Bad ass boat, post some pics

How many RPMs do you want to turn max?

It was built to spin 6k.

And playing around this last weekend I got a little more aggressive and can get it up on plane in about 14 seconds now.
roll I to 3k with tabs have down, once it grabs a little bit roll it up to 4500 rpm, soon as it grabs just a little again, tabs all the way down and she rolls up to plane and is gone. Woohoo.

Hopefully lean on her a little more this next week and see where 5200 to 5500 puts me on speed.

My planing time was greatly reduced when I went from a 4 bladed prop to a 5 bladed prop but the 4bladed one was faster

ICDEDPPL had a set of 27 pitch 18" Dia 5 blade that he was trying to sell.
Was in this prop forum, the Superhawk thread.