I have a 42 Fountian staggered engine big step hull and running some modded 525's with standard bravo xr bottoms and wondering if worth it to switch to sport master bottoms? Boat runs 90mph at 5400rpm with labbed 32 pitch Maxumis 5 blades. No blow out issues or any thing but looking to gain little speed and maybe less prop slip? Any one ever try on 42's?

What did you do to your 525's? 90 mph is really good for a 42 fountain.

As to your drive question, you may be able to lower your slip numbers, and probably improve your steering as well. However I do not own a 42 fountain, so those are just guesses.

Strong numbers for a modded 525 42. Seems you hit a good prop and power combo, nice work. I wouldnt mess with it unless you go with some Whipples.

Motors are making 610hp at the crank. Promax CNC heads, Intake opened up, extra 1/4 stroke making 540CI. Boat runs 85 loaded fuel and people 90 best seen light. Always trying to get little more!

What about the Whipple 525 Stage 1 upgrade to get some more RPM?

We already have limiters at 5600 rpm. Motors peak at 5300 rpm. Stock intakes really restrict the air but I like having all the mercury fail safes. Could pull merc intakes and gain 50 to 75hp I believe.

That intake and TB are really killing your power, you could probably make 700 + with a good intake and carb, but I like EFI to

Does anyone know what ever happened with the 525 intake Raylar was working on? It looked very promising!

I agree with the versatility of the Smartcraft and EFI. Seems you have gone down pretty much all avenues with what you have. Maybe the -2s will give you a MPH bump, possibly combine with ITS or boxes and 6 blades?

I have an 07 42 lightning with 525's and ITS with std sportmasters. I modified the intakes on the 525s and had precision marine tune them. Blueprinted hull and lowers. Would regularly run 92-93 Seen a best of 96 @ 5850. Also had labbed throttle up 6 blade 30p props. They were always faster than my herings. I also removed the cabin interior. that made a big difference in ride and handling.