Disappointed in boat with 300xs in illinois

[troycrna]

I met some of you guys on the illinois river a couple weeks ago. I was the guy with the big AAD aluminum plate boat with the 300xs. As some of you saw my boat was porpoising horribly. I thought we could weld some trim wedges and problem solved. I was hoping to hit 70mph, however I am very disappointed. I am working with bblades out of wisconsin for the props and so far have tested 3. The first prop was a 24p four blade and ran 57 mph at 5100 rpm (wot should turn 6-6100). I thought that was a good starting point but the next prop was a 19p 3 blade, it turned 6050 rpm but only ran 53mph and the next prop was a 21p 4 blade and it ran 6000rpm and ran 54mph. It seems like that motor should push that boat at least faster than 55mph at wot. We are cutting off the trim wedges and installing electric trim tabs tomorrow. Does anyone have any thoughts on this.

[troycrna]

boat is a 24 ft semi V aluminum with 6ft 6in bottom and 30 inch sides.

[RNM018]

I wouldn't hold that against the motor . It sounds like your issues are with the boat ,and set up . What does this boat have for a bottom ? Got any pics ?

Rich Martin 018

[1BadAction]

Those things look like mini industrial weight barges, I'm suprised you are getting 55 out of it.

[troycrna]

pic

[Big Johnson V8]

I ran next to you from Liverpool back up to Rocks, We all commented on how good that thing ran. You got one of the baddest boats on the river, were running 60 on my GPS and I look over and here's two guys standing up in a plate boat next to us. Keep playing with props, try a 28 4 blade trophy that will get it up in the back

[skydog]

WOW 60 in that baby is MOVING!!

[lckytrbl]

miles of wetted hull=drag

[rock]

Talk to Ryan in Beardstown. He had the other plate boat that was there. Not sure if you were gone already or not. Anyway he is well into the 80's from what I was told. Diamond motor that dynoed around 325. His boat was built by the same folks as your's I think. Ryan designed it but they built it. Someone told me he has very narrow tunnels built into the bottom but you need to talk to him to get the real scoop. Might be worth it if that is in fact what he has done. Aluminum is easy to cut and weld. Don't know if that will remedy the porpoise or not but I saw you coming south and it is certainly an issue. If you could get it to flatten out my guess is you will pick up a bunch of speed. I would put all my effort in getting it to lay down before I spent a bunch of money on props. If there is anything I can help you with, let me know.
Rock