prop help

[DAULEY]

I just installed a bravo on my 1995 blackhawk le meed help on what prop to use

[Ranman]

eek! eek! eek! eek!

[DAULEY]

need help

[Fish boy]

I am not an expert but I will try. First, did you remove the duo-prop drive that came with the boat for some reason and replace it with a bravo that now uses a single prop application?

What engine/horsepower do you have? What gear ratio? What are you using for a prop currently and what speed @WOT, RPMs?

SOrry for the 20 questions, but the info will be helpful to try to figure out what is best.

[DAULEY]

engin 502 415hp have not tried any props yet donot want to buy wrong one changed drive to make it easyer to dock have a new in crate blackhawk drive also broke the one that came on boat and bought bravo 1.50 gear ratio any help in chosing prop would be helpful
Thanks bob

[riverrat]

I would go to the mercury web site and find a loaner prop dealer nearest you & try a few props before I bought one. maybe a "25 mirage plus to start with or a bravo four blade??

[Greg Maier]

Bob,

I certainly am not a prop expert but here is my advice. I would shoot for a target speed of 70 MPH. With a WOT RPM of 5000, 10% prop slip, 1.5:1 gear ratio, that would give you a required prop pitch of 24.64 inches per rev. I would try to get a prop that gives plenty of stern lift since the Blackhawk has plenty of natual bow lift. I think the cleaver type props give the stern lift. Also, I think that more blades give you stern lift, i.e. a four or five blade prop versus a three blade. It will probably be a lot of trial and error on your part to get it right.

[Ranman]

I think that your average, run of the mill 22 Classic with 415HP 502 and 1.5:1 Bravo likes to spin a 25P Mirage Plus. This would be the most common setup. I don't know exactly how this combo will handle due to the rocker in the hull used in the BlackHawk application. You will not know what the best prop is until you try several. The Bravo one four blade is not the best choice in this application as it has been documented here to be ill-performing on Classic hulls. Some report the Bravo One four blade to be down right scary. Another good option for your boat would be a 25P Turbo One from Precision Propellers www.turbo-props.com. (http://www.turbo-props.com.) This is a great company that has gone out of it's way to support the Donzi Registry Members. The Turbo prop typically will give you a bit better handling and a slightly higher top speed over a standard Mirage Plus, but it is a very "Mirage feeling" prop. One more choice for your boat might be a Hydromotive Intimidator Quad IV. The QIV props are typically a couple of MPH slower than the Mirages/Turbos in the order of 2-3MPH, but generally provide a significant rough water handling improvement. On my 18 Classic, I have been running a Mirage Plus for 3 years. I recently tried the Hydromotive and although the top end was slower, the prop is a much better choice for my boat so I am switching.

Again, I have no clue as to how these props will perform with the rocker in your hull, but they are good performers on the non-rocker 22's. This should give you a good starting point, but by no means is the end all answer. To find the best prop you must test, test, test. Good luck and let us know what you end up with.

[Fish boy]

Cant add too much to what Randy had to say, especially with the Rocker catch- good point. More blades= less speed, plain and simple.

Do any other members live near by or do you have any friends in the area that might have some props you can try? It is not hard when at a lake or beach to just swap them for 5 minutes and see what you like better.

Personally, although my hull is a little different, I switched from the mirage to a turbo finding that the turbo did what the mirage did, only a little better and a little faster. My brother just picked up a 24 turbo for his 22- will let you know how it runs as soon as it gets wet.

[boldts]

Anyone who has talked to me or ridden in my 22 Classic before and after knows how I feel about Turbo 1 props. My Classic came with a Mirage 23" (Not the Mirage +) Boat porposed like a BlackHawk boat all through the RPM ranges. At the suggestion of a fellow board member, I bought a Turbo 1 in a 23" pitch. You can not believe how much better the boat performed both in the speed area and in the handling area. No more porposing and now I can trim the drive out to gain additional speed. Did I mention the boat went from 65 GPS to over 67 GPS? Easiest 2 MPH I have ever found for under $400! Due to still turning to few RPMs, I traded the 23" for a 22" Turbo 1. Boat topped out at 68.7 with a stock 454 and Bravo 1 with 1.36:1 gear.

My next question would be where is your prop shaft in conparison to the boat's bottom? The BlackHawks as I remember ran a higher X demension. In other words, you may be able to run even more pitch because of a higher X demension.

One of the neat things about the Turbo is it's smaller diameter of 14 1/4". This greatly improves the boats handling because you don't have a big 15" + prop trying to paddle wheel the boat every time it goes around.

I have to disagree with Randy's remark that the Turbo basically works like a Mirage. Not on the 22 at least! I'd be glad to let you drive mine with the 23" Mirage back on her and then the 22" Turbo. No likeness at all wink

E-mail or call Scott Morgan or Steve McLelland at Turbo. You won't be wasting any money on the 22 Classic hull. :)

[Ranman]

Boat porposed like a BlackHawk boat all through the RPM ranges. eek! eek! eek! :D :D


Scott, I think you are making a slight mistake here. The Mirage Plus cannot be considered equal to a standard Mirage. Did you ever run a Mirage Plus on your boat? I found the Turbo to be very similar to the Mirage Plus (not std Mirage). I have run a Mirage+ for 3 years on the 18 and and also ran the 25 Turbo 1 last weekend at Cumberland. \

Granted the 22 may be a whole different story, and I was comparing a Mirage Plus to the Turbo (vs a standard Mirage, which I have heard are less than desirable). On the 18 Hull the Turbo 1 and Mirage Plus are VERY similar with a slight edge given to the Turbo in my eyes. Now I know we are comparing apples to oranges as the topic in question is referring to a 22 hull and my testing was on an 18 hull. I just wanted to clarify that I was comparing a Mirage Plus to a Turbo 1. Lastly, I don't know if you've tried the Hydromotive QIV, but after running all three props on the 18, the QIV is DRAMATICALLY different from the Mirage Plus and Turbo 1. This dramatic difference put the Mirage Plus and Turbo even closer to one another compared to the QIV

I just wanted to clarify my point and re emphasize the boat and equipment I compared/tested. So in my case and opinion, on an 18 Classic the the Turbo 1 is very similar to the Mirage Plus. Furthermore the Hydromotive QIV is very different than the Mirage and Turbo.

In your case a Turbo 1 is very different (and more desirable) than a standard Mirage on a 22 Classic.

[boldts]

Sorry Ranman :D I missed the (Mirage Plus) in your comparison. I've not had a chance to run the Plus or the Hydromotive Q IV. Sorry, my bad frown

[Ranman]

Scott,

No need to apologize. :D You weren't wrong per se, I just wanted to clarify my own experiences with the props. Again, I can only speak for the 18 Classic hull, not the 22. I've just heard that there is quite a bit of difference between the Mirage and Mirage Plus with the Plus being much improved over the standard.

[MOP]

So I learn some more, I think you did not modify the X demension which is higher than a standard drive. Does'nt that make it possible to run a higher pitch. On the issue of trying props there was a post last fall about one of the companies that had a try before you buy policy. Not sure if it was one of the above mentioned.

[Ranman]

If the X dimension is higher, generally you can swing a larger prop. My guess is that the BlackHawk cutout is no more than 1"-2" above a standard Bravo install. If it can be verified that the X is indeed higher, maybe I'd start wit a 26P over the 25P in a 3 blade application. If looking into a 4 blade, reduce the pitch 1". It's hard to say how the possibly higher X and hull rocker will react and thus alter the optimum prop setup. I would think a 25P or 26P (if X is raised) would be a good start. You just have to bolt something up and see what happens.

[Rootsy]

when it came time for my shallow pockets to do prop testing i found my wishes fullfilled by none other than E-BAY!!!!! you have to know what you are looking at... check part numbers.. and keep an open eye and be patient sometimes but it can really be worth it... and generally if you don't like the prop you can get AT LEAST what you have into it out of it when you sell it.