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cherry82482
06-17-2008, 01:24 PM
I'm currently running a 23 pitch mirage plus prop. I'm looking for more top end speed. What pitch is recommend? Running 22 ZX with 502 EFI.

Mr X
06-17-2008, 02:06 PM
I'm currently running a 23 pitch mirage plus prop. I'm looking for more top end speed. What pitch is recommend? Running 22 ZX with 502 EFI.
Bravo One 24 Lab

cherry82482
06-17-2008, 02:14 PM
Yes it does have a bravo one outdrive but what does the LAB stand for?

BlownCrewCab
06-17-2008, 03:29 PM
He's talkin about a "Bravo 1 " Series Propeller....The LAB, Means Lab Finished, the blades have been calibrated, Thinned, Polished, Etc

BlownCrewCab
06-17-2008, 03:37 PM
What RPM/ Speed do you get with the 23 3 Blade? A 3 blade is easier to spin and usually provides more top speed, BUT, The newer props that are out some 4 blades are pretty quick too, especially if it has been Lab Tuned/Finished. So Tell what you Get (Speed and RPM) and I'm sure someone here will know what you need.

blackhawk
06-17-2008, 04:25 PM
I'm currently running a 23 pitch mirage plus prop. I'm looking for more top end speed. What pitch is recommend? Running 22 ZX with 502 EFI.

As blowncrewcab stated provide your current rpm and speed to see where you're currently at.

cherry82482
06-17-2008, 08:13 PM
Current RPM at WOT is 4,800, top speed with just me in it and 1/4 tank of gas is 67 MPH.

Mr X
06-17-2008, 08:30 PM
Then you will not be able to turn that 24 Bravo One Lab.
You might want to get that Mirage tweaked a bit and stick with that.

The Hedgehog
06-17-2008, 09:00 PM
What X said. You might be able to hit 70 but that is about it. Maybe a little more with a chop but not much more. I hear about guys in a 454 Mag bumping on 70 but not seen it yet.

Put a blower on it and you will fly!

cherry82482
06-17-2008, 09:07 PM
Thanks for all the help. I think a blower is the best idea!!

kramsay1234
06-17-2008, 11:29 PM
I have a 22ZX with a 502 Mag. The stock prop on that boat is a 26 pitch Bravo 1 - 4 blade prop. I just put it in the water for the first time this past weekend and got 68 mph on GPS with 3 guys in the boat at about 190lbs each and 3/4 tank of gas. It didn't seem to react or increase speed any with trim so I will have to play around with the trim to see how to tweak some more out of it. My 23 Scarab loves the trim and definitely breaks loose with trim and speeds up.

Anyone with this boat that can shed some light on how best to trim it out for top speed it would be appreciated.

I have a 23 Mirage Plus Labbed that I didn't think to put on the Donzi, but I could try it. But I figure if its slinging a 26 four blade to 4900-5000 rpm, I can't see a 23 pitch 3 blade working very well.

I am still in trial mode with this boat as it hasn't been tuned-up or anything as yet. I figured the boat has to do low to mid 70's with a 502. I know it does low to mid 60's with a 350 mag. I can't imagine that the 502 Mag won't give it another 10mph over the small block. Also, they sling a 24 pitch Bravo 1 prop with the 350 Mag, so again, a 26 pitch for a 502 seems reasonable.

BigGrizzly
06-18-2008, 10:22 AM
Actually I can shed some light on this. First is that your tabs are dragging. They all seen to be set too low. I had to shorten the rams on my son's. Remember that a 7.4 MPI is only good for 64 on that boat. The 350 has the same power and is lighter. Baby Donzi has that set up ask him what he turns speed wise. the 23 marage is too small.

kramsay1234
06-18-2008, 09:34 PM
Griz - thanks for the info. Are you saying that adjusting the tabs with the switches won't help me because I am battling a setup issue? That seems strange that Donzi would sell the boat that way. Is there any adjustment I can do without literally removing the tabs and shortening the ram? Not that I don't believe you because I do. The fact that trimming the boat out wasn't really speeding me up was crazy.

I heard from Rip that he was getting mid 70's out of the box on GPS with this setup.

Maybe Baby Donzi can chime in as well. I need some help winding this boat out. I upgraded from the Scarab to this so I could do 75 instead of 65. So needless to say 68mph is just not going to cut it...:garfield:

osur866
06-18-2008, 11:41 PM
Kramsay, look under the tech section and look a the thread "Bennett trim tab modifications" and you will see what Griz is talking about. This is one of many mods I did over the winter to my 18 and yes you will or at least I noticed a difference. Can't help with the prop selection on the zx but take a look at your tabs and the modification thread . Good Luck Steve

kramsay1234
06-19-2008, 12:02 AM
Interesting and thanks for the thread reference! No reason not to do this as a start. I have the same tabs on my Scarab so I am going to look at where they are mounted relative to the hull bottom. All I know is right now I seem to not get the effect out of trimming out the drive that I would expect. As I said, I only use the tabs to plane with a lot of people or balance excess weight. Never for a top speed run.

This boat better do 75 or I will be very disappointed.

BigGrizzly
06-19-2008, 09:24 AM
Your going to be disappointed, That boat is heavier and taller than a classic hull. I would be surprised if you do 75 even with one of my props. My son's 22ZX with the wipple did 82 mph on a good day but settled on 78 to 80 on normal days. We set that boat up right too. Like Steve said Look at the tech section on the tab subject, and yes it was set up wrong from the factory, Like most of them from the 80s and 90s and even later.

kramsay1234
06-19-2008, 05:15 PM
Griz - Thanks very much for the tip on the tabs. I read all there was and now will contact Bennett for any additional input. This will be my first mod. Very much appreciate all the help that these forums provide and am looking forward to many more tips.

I actually think I got pictures of your sons boat when he was selling it. When I bought mine, I saw his a week later and I passed the info to my uncle. But I know he sold the boat already, but looked like a good package.

What are "your props" you speak of? I spent more than my share of time on going through different props for my Scarab. Would love to eliminate all that and just have someone tell me which was that right prop. I was emailing one guy on here a few months ago that had the 99 with the 502 that said he got 80mph and I know he was running a 26 p Bravo labbed prop.

I really want to see this boat do 75...

Boiler56
06-19-2008, 05:30 PM
I can tell you that Big Grizz walked me through the mod to shorten the tab height. It only takes about 10 minutes per tab, and I did notice a legitimate 1 mph increased top end on the GPS. He has also been great helping me find the right prop for my 22ZX. The one thing he has showed me, is that the only way you can find the right prop is through trial and error. Grizz, I still need to try one of your three blades for the days when I just want to wind it out. I'll give you a call soon.