I have a 38 fountain that had 496 ho in it. I re-powered with 635hp boat only runs 84mph anyone know if the x is different on the 496 boat then the same with 525??
Thanks Simon Sez

Year of boat?

Simon,

Hope you and Mel are doing well. I can check my 2000 38' next time I'm up at the like (lake season is pretty much over up here in OK). It came with HP 500's, so I would assume it's similar to a 525 setup. Remind me, are you staggered or side by side? Mine's side by side. Tell Deluca hey for me next time you see the old man (hated missing his Bday party). Take care.

Brad

its a 2003 staggard boat ran 73 with 496 1.65 gear
32 prop. changed to xr 1.50 same prop now runs 84
should be allot faster got my but kicked by stock 525
in same boat .

Have you figured the slip % ?

What RPM are you reaching?

5200
rev limit set at 5800 just not getting it done.
same boat with 525 and 32 p is getting 5400 89mph
Thats why I am curios about the x dimensions.

My motors make 700 ft pounds of torque at 5000

I'm running just over 80 on GPS with the "small stepped hull" and around 550hp per side from my modified HP 500's. 1.50 Bravo I's with 26P Hydros turning in (not labbed) at 5,350 (on the limiters). I think you have too much prop. Have you tried a pair of 30's or 29's? What RPM did your max HP come at?

According to the numbers you quoted your slip is 20%. Thats unusually high. Should be around 10%. Did anyone ever work those props for you? Something is not right.

Both motors dyno the same? Do both motors sound synchronized at higher r.p.m.'s? Did you set/check your toe-in or toe-out properly? Are both props a matched set & been checked for trueness? Are you on the rev-limiter(s)? Don't ignore the basics. Ed