'98 33zx Daytona speed question
 

Hello guys,

I'm very interested in your oppinion. I just bought a early '98 33ZX Daytona with hp500 carburated engines - the boat has neraly 100h. It is a stepped hull and weight 8600 Pounds (with 1/4 tank) and has no buttom paint. I went on normal water and tried to get top speed, but i can reach only 72 mph by 4.900 till 5.000 rpm. The props are 26 Bravo 1, the owner said that were a labbed version.

So what i am doing wrong??:grinser010: I read a lot of in youre articles and every boat seems to be faster even with smaller hp... Has anyone an idea?

Thanks for your answeres,
Greetings from Germany

Well the first thing is The 33ZX weighs more like 9800 dry. What is your trim at ? Do you keep the tabs up? She should be running 28 or possible 30 pitch on the 500s. Your top speed should be more like 76-78 MPH with carbs. Unless your boating in Freshwater. then you will loose 2 mph. Also are you sea level or in the mountains? all this comes into play when you are trying to get more speed.

Hello,

first thanks for your quick answere. The sea level is zero, the temperature is very cool. The tabs are up, and the trim is on 3,4 or 5 on my indicator-that doesnt matter, it runs 72 (all gps) what trim level should be ok? She runs fast to 70 but then she is not going on... The Donzi was at a lift and it weights there 3900kg. Perhaps the lift isnt correct, even when the lift is new? But i have no microwave, no clima and it is a daytona edition (vacuum bac)?
The engines are going both close to 5.000 (gaffrig instruments). Should i test the engines?

Greetings

I would do a compression test and a leak down, you may have a loss in HP. The 33ZX is very trim sensitve and by you going up to 5 and not hitting the rev limiter at 3 with 26 Pitch props is telling me you have something else going on.
My 33ZX is a newer addition with the same set up as the Daytona but I am running 496/HOs with 26 props top speed 74 mph at sea level. My trim is at 3 if I go any higher she blows out and looses speed. I am going to go with 28s I hit the rev limiter at 5200 at 3 trim.

Hello Shanghied,

i will test the compression on saturday, what do you mean with leak - where should i search for a leak? I'm going to test the spark plug, what else can i test? But then i should hit the rev limiter too, or not by turning the 26 - so i need perhaps then new props... any suggestions :drink: ?

Thanks a lot for your help!! It is my second donzi and i realy love them...

8600 lbs@72 mph is not too shabby!What does the factory claim it should go with 500's?

Shanghied's Speed estimates are inline to real world. I have seen very low 80's years ago in a 33 daytona with 500hp efi's that I ran with the Donzi rep years ago. bout 81-82 on GPS if my memory is correct. Jamie / Lakeside

I am running my 38ZX @ GPS 75-76 @ 5200-5300. Stock 500EFI's. The 38 weighs in at about 11,500 dry.

I would think the smaller/lighter 33 should be running around 79-80.

David
you are still to slow with your new Boat!:lolhit::lolhit:
c u on the next Poker Run!:evilb:

Hello again,

thanks for youre informations!! So last weekend i tried again and reach 75mph, my mistake was to trim wrong:rolleyes:

I think it is still to slow, but with better props and some work on the engines i'll reach a higher grade :evilb:

Thanks to all for your answeres :kiss: