Mid 60's GPS With the MAG get a labbed prop and upgraded exhaust and you will be very close to 70.

Can someone explain the labbed prop? i have grown up ona boat and not sure what that does to it. and change exhaust?? its strait through the hull, so I am assuming you mean headers? what do they run for a boat? never had on a boat only cars.

It has a Super Sucker carb spacer on it......


So in my opinion it's basically stock.. :D


Doug

Yes, if you want to cross 70 it will take more than a labbed prop and exhaust. Cam and head work with that will get you to 75.

I have a 98 donzi 22zx with a 99 454mpi and top speed is abouy 63. Nice boat but a little slow for todays standards!

22zxla,
Is it a stepped hull? and is it a mag?

It should be stepped if it is a 98. I would bet it is a non-mag.

There was a guy on the Donzi net that claimed he broke 70 with a stock 454 mag MPI. About 5 very knowledgable people quickly proved him wrong.

A 22ZX with a 502 Mag will run 69 on the GPS. That has been verifyed by someone that knows the boat very well and can drive it just right. He had it propped perfectly. I think he was running a 25" prop. I can find out exactly.

A 454 Mag should get you around 65-67.

If you want to break 70 (a real GPS 70 not pitot speedo) you will need around 450 HP to do it right.

That would entail:

1. A more effecient manifold or headers (Stainless Marine, EMI, Lightning, etc)

2. Bigger cam

3. Valve Job and probably some punched out bigger valves (eg the size they use in a hp 500)

4. Reprogrammed ECU

That will take you over 70 with authority.

Doing just the manifold alone will get you close due to weight savings and a few more hp. Maybe 68-69 in the right water conditions.

I would think that hull with a 454 mag would easily hit 70. I had an 89 22ft Checkmate non stepped with that motor and it ran a real 68 on gps. drive was a bravo with a 3 blade 25 p. there was a couple Donzi 22's on the lake and in rough water I couldn't keep up.

sorry, yes its a stepped hull but not a mag. Think its the 330 hp.

No sir. It won't The Donzi is probably a good bit heavier than the Checkmate. That is why they like the rough water.

It is a great platform to mod. With a little power it moves on out.

The same can be said for the 26ZX:evilb:

I had a 27ZX non-step hull. I could run WFO in it when others were heading in.