500efi to a 750hp motor-speed increase?

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08-24-2007, 06:07 PM

Brian C

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500efi to a 750hp motor-speed increase?

I'm thinking about swaping out my 500efi's for a motor with 750 hp & just wondering what everyone's opinion on what my speed increase would be? I have a 2001 Donzi 33zx. Thanks.

08-24-2007, 06:41 PM

Flashwave

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I'm guessing your boats weighs about 11500 pounds and runs about 75 MPH with 940 HP (Twin 500 EFI's) Does this sound about right? Move up to 1500 HP (twin 750s) you should be looking at 95 give or take.

08-25-2007, 09:21 AM

Brian C

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That's right on the weight. On GPS I have seen 79.6 & can run 77 without an issue.

08-25-2007, 01:32 PM

Young Performance

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You should pick up about 15 mph. That is about a 225 hp increase, using 15 hp/ mph, gives you 15 mph increase. Not an exact formula, but gets you in the ballpark.

08-25-2007, 04:32 PM

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Quote:

Originally Posted by Flashwave

I am guessing 92

mine picked up around 18-19 at 750hp

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08-27-2007, 06:03 AM

Canada Jeff

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Well I'm just a single engine, but I Whippled my HP500EFi to at least 750hp and have seen 14 mph. I think there is more, but I'm fine with it for now. My boat weighs 4500 lbs dry.