Very nice work as usual Ron. Thanks for sharing information. It's always nice to learn more about something your passionate about!

I think you need a pair of these!

http://m.ebay.com/itm/Gas-Turbine-Je...852?nav=SEARCH

I have a 308 as well, been following this thread, among others, to see what others are doing. I'm set up pretty conservative and haven't played with props, heights or anything. My big question is which props seem to get the best all around performance, save the gear case, and have a great cruise speed. Right now i run 15x32 3 blade cleavers, and the boat runs right around 102, with 25 PSI.

I have the same boat. Keep spining the props inward the boat needs stern lift. Drive height should be around 1.75 above the bottom thats conservative. I would switch to 5 blade dewalt keep in mind if you are runnung xs motors they hate to rev to high, set it up to max rpm 6200-6300. The 3 blade props are very tough on the lower units. Good Luck.

28Skater, I have limited testing with props and motor heights thus far as we have been focused on fine tuning the water pick ups for good flow and the least amount of drag. What I can tell you so far is that I have tested a set of 3 blade mercury cleavers 30" pitch that produced a slip of 7% and a top speed of 102 in S.FL with 1/2 tanks of fuel and 3 people. I also ran a pair of 5 blade 29" pitch Dewalds that were through hubs. They produced a slip of 4.5% and a top speed of 104-105mph same day and same load conditions. Motor at the time was 1 7/8" above the bottom. Currently running inward rotation. I plan to test multiple engine heights and also more props. I believe I can get this thing to run an everyday s. fl speed of 110mph.

I agree the boat needs stern lift. I have the motors turning out, may change things up in the spring.

If you are turning out that is the proper rotation for stern lift and keeping the nose down. Inward rotation will cause bow lift.

Ron I could be wrong ? but all my experience cats are opposite of v bottoms. Cats spin in to pick up the back of the boat. Where v bottom spin in to pick up the bow. Again I could be wrong.

I think DR is correct!

Bill,
My question would be why would the type of hull matter. It has to do with the blades turning through the water. The type of hull should not matter IMO.
Just saying. I know this I will be changing rotation soon and see how it affects my boat and CG.
The other thing that affects transom and bow lift is type of props and rake.