You will need about 400+ Hp to get into the 70's. The Donzi's are typically heavier than the other similar sized boats on the market..

Also ZXXX Donzi's posts are pretty accurate.. I can speak & vouch based on my personal and professional experience with the Donzi hulls.. :) Jamie / lakeside

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haha ok, we are all talking GPS speeds and i like that becasuer i know the speedo's on boats are normally off. but what do you think the speedo says on this boat. think it showing 75 and thats why the guy says that?

so whats the cheapest mod to help the most. (best bang for your buck) how where would it put it. mph

easiest & least costly to more costly & indepth:

Propping the boat correctly if not already done.. it could grab you 1-4 mph

Beyond that upgrading the exhaust to a lighter better breathing system. = Weight reduction & small speed increase posibly an additiona mph or 2

Altering drive height could gain you another couple mph

Doing internal engine performance upgrades or adding a supercharger.. Gain is dependent on how much you are willing to spend & how far you want to go..

;) Jamie / Lakeside

If you want to really move and the engine is relatively fresh, slap on a Procharger. That will be good for at least 10 mph, probably 15 mph. Jamie here has done it on that boat with a 350mag. He can tell you.

If you want 5-8 mph, do the cam, heads and exhaust.

Do both and the boat will be out of control fast!

Other than that yout increases will be small. Also, don't think that s bunch of the small changes will be cumulative. Let's say you can get a mph for doing a better aircleaner, then 3 mph for exhaust and 2 mph for a cleaner ECU program. The sum total of that will not net you 6 mph.

231 hours. thought about a procharger.

With over 200 on the clock you would want to do a leak down & compression test before boosting th engine. If all is in spec you could procede, otherwise if your insides are worn it will most likely give you grief.. :)

If you do have wear you may be better off doing a big NA build instead and having a fresh engine in the process.. ;)

If you want to look into it further feel free to give me a shout.. :) Jamie / Lakeside

I had 280 hours on my 502 mag and slapped a procharger on. Got two seasons without a hitch. I am rebuilding now to go bigger.

You will get the biggest bang for the buck with that. Make sure that you set it up right.

There is some merit to the rebuild and go big power NA. High 70's to maybe 80 with a fresh motor has some pretty good merit. It all depends on how long you plan to keep the boat.

I had a 99 22zx with the 7.4 MPI (310 hp) it did 63 consistently, once on a cold day with little fuel and helpful current I hit 65. For a little boat it was pretty good offshore, and you can sleep 2 in the cabin. Mine was blue and yellow with the stepped hull, beautiful boat.

IMO don't waste your money on a labbed prop you will just end up having to replace it when it throws a blade or gets cracked, its not worth it for 2-3 mph, better off with a 5 blade to get a better cruise speed which is where you will spend your time anyway. For the price of a labbed prop you could buy one that has great top end and one that is good all around.

My 99' 22ZX w/454MAGcarb/Bravo1 did 70-71wot....Stainless Marine exhaust system, 25" 3-blade labbed Mirage. No step, 385hp @ crank stock, probably 400+ w/ exhaust. Every 20hp gains about 1mph, on average up to a point

ooops, I meant 1997 Donzi 22ZX....