28 donzi w 350s
 

was looking at getting a 28 skater, but now i'm looking at a 28 donzi with a pair of 350 mags...bit less money, and lower insurance.

soo...what I want to know, is what can I do to the motors, to get more speed, 75MPH just doesn't cut it, wouldn't mind hitting 80 or 85 MPH+...but not sure I want to get involved with prochargers...thinking some simple engine mods with bigger props...looking for advice...

28ZX twin 350 will run 72 MPH GPS all day long...75 MPH is a little on the high side... I owned a 2000 28ZX 350's (stock) ran 72 MPH never saw 75...


If ya want more speed I think superchargers would be the ticket would make that boat a sweet ride and would get you to your speed goals....good luck:D:D


Undertaker:D:D

Props that come from the factory on the 28 are the fastest props for the boat IMO...I believe they were 23P Mirage + boat ran great with those props...

28 is a great boat. Sc's would be the hot ticket in there. We have done our fair share of them. I am also doing a whipple in my new Donzi.. They are wave crushers. If you get one & want to upgrade it whether you want Sc's or just more power without em give me a shout.. However exhast alone wont make much difference. You will need to do a lot more to get the speed without using an sc.. :) Jamie / Lakeside

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Now...if I want to mod some engines, am I better to go with the scorpion 377 motors, or the twin 350's? What do SC's do to the motors? What I've been told is that SC's are engine killers, and to stay away from them. There is no doubt they provide the power I'd require. Any suggestions on SC's I should look at?

Has anyone added SC's to a 28?

Thanks!

what sort of power would I be looking at with a set of whipples? Now...the next question, how do I go about finding the right props?

If you dont want to do any mods go with the scorpions, otherwise steer clear & stay with 350 mags.. They are difficult/costly to modify & improve upon.. Also any Sc that you would add to it would be a custom install.. The 350 mags are easier to get stuff done on & find things to upgrade even though they are still both small blocks. ;)

As far as Sc's eating engines, that is a myth. However if they are set up wrong then yes they will definitley shorten the life of an engine & give you a lot of problems above & beyond any normal initial tuning quirks.. Also FyI do not go very heavy on the boost, everthing in moderation. A little bit goes a long way.. :)

As far as props genrally you jump about 2 full sizes or more..

Jamie / Lakeside

Great!!! That helps out a lot!!! Now...how much boost should I be looking at for these? Any idea what kind of horsepower I will getting, along with a top end?

Another quick question, I've been doing some reading, and my understanding is that DONZI changed the profile of the 28 in 2002? What exactly did they change? Can someone post some pictures of the different profile of the boat?

HP will vary on quite a few things.. However either SC will make a noticable difference.. I would say boost levels should be in the 5-6 psi area. ;) Jamie

what SC should I be looking at? A whipple or a Procharger?

If you get a 28ZX with scorpion motors you will be at 80 MPH bone stock...

as far as SC Jaime will steer you in the right direction.....I would say procharger if it was me....:D:D

Here is a few pics of my '03 im not sure what they changed in '02 but thought i would offer these pics to you. Btw this boat is for sale i have twin 6.2's from what i hear they do well with boost.

http://i18.photobucket.com/albums/b1...fjuly07003.jpg
http://i18.photobucket.com/albums/b1...fjuly07002.jpg
http://i18.photobucket.com/albums/b1...fjuly07001.jpg

Both Procharger & whipple make good units for them. It is a matter of personal preference on that engine.. :) Jamie / Lakeside

Bingo...

Any way go the Zx's are a great boat.. If you dont like the idea of boosted engines go for the scorpions, If I didnt like boost so much I would buy a scorpion equipped boat with no problem. Just fuel em & drive em and service as usuall.. :)

There is a lot to be said for some small blocks.. :) :ernaehrung004:
:cool-smiley-027: And yes it should run around the 80mph mark with the 377's..

Jamie / Lakeside

28zx
 

I have been looking at the classifieds for 28zx's. I find some that look different than others. Mainly the top deck. Im not sure if its a year thing or not. I really like the looks of a 1999 28zx I found with a single. The deck and wind faring is differnent than some. I cant tell if the hull is different. Can anyone explain? I want to use this in the Ocean mainly off Southern CA.

Do not get a 28ZX with a single you will not be happy....

Inexpensive

Fast as hell

Reliable

pick 2

:violent-smiley-045:

How is a 28' Donzi in the rough stuff, ie, rough chop?

The zx's especially the 26 & up cut thru Like a hot knife thru butter.. :D Jamie / Lakeside

Is that because they are not fast enough? I know of a 28 with a single that runs in the mid 80's. Well. You would have to drop some coin to get that out of twins.

IMO the boat is better balanced with the twin small blocks, I had a 2000 28ZX w/ 350's boat ran 72 mph all day, throw some whipples on it or get scorpion motors and you will run 80-82 all day....I know a guy who has a special built motor in his 28ZX and has a ton of money in the motor over $10 g's and still runs about 76-77 on a good day.
IMO you need a lot of horsepower in a single 28ZX to run in the 80's they are heavy boats.....


Undertaker

Also IMO a single 28ZX with stock motor would also be a pig to get up on plane with the twins it was not an issue..that is what I mean when I say (better balanced)....:D:D

So have you driven a single? I have

They get up on a plane just fine. Even with a shorty.

I think that the twins are nice but the boat runs just fine with a single.

You can get one with a nice reliable 500 EFI and it will run 72 just like on with twin 350's. If you want to run in the 80's you only have to buy one blower. The singles have a bunch room in the engine compartment. Those 350's look shoehorned in to me.

He must not have it set up right. I have a friend that has one with a blown 500 EFI that runs 85 with on 5lbs of boost. I have personally driven it at 81mph and it handles great.

Next year he will take it into the 90's. That would be one heck of a feat with twins. I guess it could be done with whippled Scorps. Now you are talking about serious

Like I said its my opinion and preference, I have owned a driven a twin 28ZX & 33ZX now own a 22 classic....never have driven a single 28ZX so I will not say anymore I will take your workd for it, my only reference is the guy I know with the 28ZX with the worked motor who runs 76-77MPH tops..


How much HP does the 500 EFI w/supercharger boat produce...just curious....:D:D

Also when I said I would not want a 28ZX single I was talking more about single stock motor vs twin stock motor, you can always add HP to any motor and make the boat run faster....but for somebody who is buying a Donzi 28ZX for the first time IMO I would go with a stock twin boat... You see more twin 28ZX boats than you do singles...I think and I am far from a Donzi expert it was because the boat ran and performed better STOCK with twins than single....


Undertaker:D:D

Ladies, ladies, ladies.... fight nice.. lol :D :D

The 500hp with an m3 has to be roughly in the 700hp range with 5psi.. That could equate to apx very low 80's with the right set up..

That said the person that Undertaker is talking about I know as well.. I didnt do the work on it, but it does only run in the mid to upper 70's on a good day from when we ran with him in a poker run a while back.. His engine though is not putting out 700hp, my guess is that he is in the 600 range.

In all honesty there is no cheap way to go for big speed #'s in this hull, it all costs money.. It comes down to preference..

Me for example I am not afraid to put money into what I like.. There are pros & cons about single engine & twin engine applications.. Out of the box the twin engine small blocks are faster in the 28 than the single. Even if it had a 500 or 525 in it, the twins will still be giving it a good run for the $$..

If you are looking for flat out potential there is a lot to be had by working 2 small blocks in that 28..

Just m 2 cents on that hull..

Now back to our regularly scheduled program.. :D Jamie / Lakeside


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Who you calling a lady:D......my point exactly you need lots of HP to move this heavy boat....Oh well I am just a stock 496 HO 22 classic owner, I can't hang with the Big Donzi, Big Horsepower boys......or can I...:D

What would a ZXO run with a Raylared 496? What about a Raylared & Whippled 496? I've looked into this as my next boat and would like to take my engine with me. :D

Dang it Jamie. Can't you let us have a pissing match without your two cents:ernaehrung004:

No, I would not have a stock 28 single over a stock 28 for the same money with twins. But then I would not have a stock anything:cool-smiley-027:

I guess that my point is that a properly setup (non stock)28 runs fine.

Jamie is pretty close on with the hp/speed numbers. My friends blown 500 efi was programmed by Marc Boos who got around 750 on the dyno with that setup. 750 hp+shorty gets him to 85 on the nose. Actually his high number is 85.9. That aint bad at all especially since he has about as much invested in the boat as a stock 28 with twins that runs 72.

Now as far as Fasttrucker's 28 goes, it sounds like Jamie really needs to set him up with a blower so he can run in the 80's too:D

Geez.....
Looks like I need to pay more attention to whats going on in here.......Thanks for the props Bill......however I will not be able to keep up with you in the near future....once I hit 250-300 hrs take the motor out.........and add some goodies and then a little more boost.....maybe then maybee I will be able to keep up with your new project....I do love my 500 EFI M-3 set-up! for now mid 80's is fine with me.
LRT

250-300 hours? That would be optimal but I doubt you can leave that boat alone long enough. Give me at least a year in the catbird seat and be careful or else we will be hanging No 6's off our boats in a couple of years!

There is starting to be an opinion around my house that you may have inspired my latest project. I have not let on that its true. I dropped by Eddie's to take another check today. I guess that I had better get used to that. Breaking the 825 hp make is going to be expensive.

Donzi 350s
 

Im not really interested in big speed. I just want a boat large enough to handle Southern California oceans at a comfortable pace. I would prefer to do 50-55mph all the way to the islands. Ive done it in my Scarab 22 on calm days but those are few. I figured a donzi 28 gives me a longer hull, better ride and a single could still get me the speed I wanted. Plus Better gas mileage.

Basically it takes x amount of hp to push a 28ZX at a certain speed. It also takes basically the same amount of fuel to generate that hoursepower. It does not matter whether it is a twin or single. The single will be a little more efficient because of less weight and less drag.

If you want to run at 50-55 all the way in a stocker and run offshore then a twin might be the answer. If you could find one well dialed in with a 500 EFI that would work as well and be slightly more efficient. Undertaker is right that you can't do that in a stock 502. If you are okay cruising around 45 you can do it with a stock 502

I have known Bill (Fasttrucker) for a few years now.. Nice guy to run on the bay with.. I have been telling him for a while now he should have me hook him up with a blower shop or whipple set up in that thing & be done with it.. :D Jamie / Lakeside


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If thats all you want & you dont care about twins look for a 26zx.. Same boat less 14"... They have the same amount of cockpit & cabin space. The interiors are the same as the 28. The only difference is in the engine compartment. The 26 is a wave crusher as well.. I love mine, especially with my new blower motor.. Now I just have to finish propping it out.. Then I can load it with tits & ass this coming summer..lol :D :D :) Jamie / Lakeside

.

I guess that my point is that a properly setup (non stock)28 runs fine.


I agree 100 percent....
If ya buy a 26ZX or 28ZX or 33ZX or 22 classic you can not go wrong because they are Donzi's and are great boats:d

Jaime, I HOPE you get your boat on the bay with us next summer...I promise to keep you & fasttrucker behind me at all times:D


Undertaker

We plan to go boating on the bay with you guys this coming year.. I really missed not getting there this past summer.. I guess I will have to just go away twice as much this year to make up for missing out last year.. :D

As far as keepin behind you?? Sure if ya have some eye candy on board I will stay behind ya all day.. lol :) Boating is not all just about goin fast, you have to take in the sights as well.. Tell Kim to get her Bikini ready, Maybe her & Kristin can match.. :)

Jamie

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fuel consumption...
 

In an Active Thunder 28 w/350mag/MPI's I get 2.8mpg at cruise,32-3500rpm's; this is better than a single 500hp, 500 or 525 efi....Probably 496 too. We run with a guy from NJ in some pruns in his 28ZXO, nice boat but is not able to handle the rough stuff quite as good as the AT. Not quite as deep, little less freeboard and more side to side rolling in the crosswake "washing-machine" type stuff. The boat is 1-2 mph faster than my AT 28 with same power though. Nice efficient hull; great all around boat; very capable compared to most 28's.
The twins are the way to go if you plan on going offshore though...think about it.
The 350mag/MPI's are turn key, fuel misers with no issues. The 377's & 6.2's have had some issues.
I have almost 400hrs with no upgrades except Stainless Marine exhaust; added 150 rpms.