Offshoreonly.com - Speed and set up?

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Quote:

Originally Posted by teamsynergy (Post 3753364)

2003 31ss 575sci's, superchillers, modified ECM's, ported heads, full roller cams, and other "assorted" goodies :)
Running XZ's at the time, now running XR's... a tad bit slower as they take at little more HP to turn... still mid 90's.
Boat is also fully loaded ammenity wise too.. a/c, fridge, microwave, tv, dvd, ect...

The GPS does not lie...

Water was 2' chop, fuel was almost gone, 1 passenger, wind behind us, 6000rpm (rev limiter set to 6800), 32P bravo 1's labbed, starved myself for a week to loose 10 more lbs lol...

The end of that post was the best! How many times has a guy with a true 75 mph boat tell everyone it does 82 mph! Then when called out they get defensive. Then the story changes to exactly what you said! I dont know about anyone else on here but I ALWAYS had a full tank of fuel when I left the marina, and never less then me and one other person but usually 4-5 total on boat. Billy the boat is sharp.

Quote:

Originally Posted by boatowner (Post 3753724)

31 sonic with twin 850 SCi it runs a steady 79 mph. 30" prop

Assuming 1.5 ratio and 5000 rpm's (should be 5400), that is 17% slip. My boats are usually 12%. Spinning a 30 to 5400 @ 12% slip would put you at 90. I would expect you to swing a 34 or so with 850hp. I think you need to look at your set up. I had a friend running 10 mph faster than you with tweaked 525SC's. I don't remember what prop.