Hydromotive results...

[Last Real Texan]

Test conditions
1997 Donzi 27 ZX twin step
Merc 500 EFI Blue motor
Bravo I drive
Temp 98 degrees
Humidity 85 %
wind calm
water smooth , no chop at all but not glass
Boat 1/3 tank of 100 gallon load
me 220 lbs




MIxed at this point. I went to my little local lake today and gave it a try. Blistering top end compared to my Bravo I .
Bravo I 24 pitch = 5400 @ 67.1

Hdromotive 26 pitch = 5050 @ 72.2

Cruise was much better
Bravo = 4000 @ 48-50 consistant
Hydro = 4000 @ 58-59 consistant

out of the hole good with the Bravo I
with the Hydro better but not great.

Bravo blow out at will.3-4000

Hydromotive worse with the blow out at the same revs.


The hydomotive seems to be a great prop out of the box....But it needs a longer more subtle diffuser ring to get hooked up better under 4000 revs... a real pain in the ass....Also it tends to porpoise more than the Bravo I , actually a lot worse, in all fairness it seems that my test conditions were not that great, no boats on the water , small local lake 6 miles end to end, and smooth water, not glass but smooth, no chop at all just a slight breeze. I am guessing that with a little chop maybe a foot or so and I will pick up a little on the top end and the porpose will subside, all this acording to Tom from Hydromotive.


Am I happy? maybe , I will have to test it in better conditions over the weekend if I get a chance, just wish it would hook up better between 3-4000 for testing , it makes it kind of a pain because you have to get to the other side of 4-4500 and then come back on the throttle.... but I want to test in chop to verify the porpoise problem gets better.

On a side note the Bravo likes to chine wald at WOT and really sucks... I have been able to setlle bot the chine walk and the porpoise with the K- planes but until I get indicaters for them I don't like to mess with them too much, don't like not knowing where they are.....

I am thinking if I can get it not to porpoise in the chop it may be the prop for me, once the prop is swapped out for one with a longer diffuser ring, then Lab it http://www2.hotboat.com/ubb/graemlins/idea_2.gif pick up another 200 revs puts me at about 74-75 MPH in the chop......Not to bad for a hull that is 28' and weighs over 7000 lbs and is running a single bone stock Merc 500 EFI....

Thanks for your attention.


Bryan

__________________
27' Donzi ZX
HP 500 EFI

[The Hedgehog]

You are killing me. My need to be testing seventy + mph props is still tied up in a house that I no longer occupy. :angryfire . Hopefully I can sell it an another month or two and recoup some of my equity. Then it will be time to add some serious Hp and I can dole out one of these :sombrero: if you know what I mean.

Enjoy Sinclair. We will be hitting the lake tomorrow. Remember not to spend all of your boating goodwill until after the Lake Eufaula Indian Summer Tequila Party on Rabbit Island!

[Chili 18]

When I first went to the Qiv OT, had some blow out issues. This was on an A1. Added a nosecone from hydromotive and it eliminated that issue and helped achieve that 'solid feel'.

Many would say its not needed at less than supersonic speeds,,, But it helped my situation.

[Havent tried the ss drive yet]....

5MPH gain... Nice!!!

[Last Real Texan]

You are killing me. My need to be testing seventy + mph props is still tied up in a house that I no longer occupy. :angryfire . Hopefully I can sell it an another month or two and recoup some of my equity. Then it will be time to add some serious Hp and I can dole out one of these :sombrero: if you know what I mean.

Enjoy Sinclair. We will be hitting the lake tomorrow. Remember not to spend all of your boating goodwill until after the Lake Eufaula Indian Summer Tequila Party on Rabbit Island!

Sanchez with a reach around wearing a wool suit in 5 'O clock traffic in 99* heat with 100% humidity and no A/C driving a 1970 Pinto...like the stinky finger.....:kaioken:

[fasttrucker]

Too bad your not from around here, would like to swap props for a test run.Iam running 26-pitch throttle up lab on my 1998 28zx 500hp+ set-up.I seem to be going a lot faster then you hit 78 last weekend ,boat with low fuel.

[Last Real Texan]

Too bad your not from around here, would like to swap props for a test run.Iam running 26-pitch throttle up lab on my 1998 28zx 500hp+ set-up.I seem to be going a lot faster then you hit 78 last weekend ,boat with low fuel.

GPS or speedo in the dash?
Salt or Fresh Water?

You stated 5300 Revs & 78 Puts you slip At 10% pretty good for a V- hull
Ever figure out how your Drive was set up in relation to Prop shaft below keel?

Great #'s I need more info

Bryan

[fasttrucker]

Iam heading to boat today Ill try to look at things The measurement of the outdrive to bottom?My boat really runs fast on low fuel.I let it go to dead mty on the gauge last weekend because of fuel prices.They are now lower,I run speedo which I checked against a gps.Gps lies :rolleyes: and says that my boat is running 2 or 3 mphs slower then my speedo.

[fasttrucker]

Back from my morning run! wash...wax.. :superman: ..add oil.....drain water....launch,,,Boat ran great no fuel :crossfing ,just me.. :checkered ..79mph :shocking: 5400rpm.Then went to buy fuel put in 82.5 gal.Donzi says 94gal tank?...Then ran 75.maybe.76 mph 5300rpm.....As far as my lower unit the cavpitation plate is even with my bottom of my boat.like I said before we did a switch to a low water pick-up unit.I think it is mounted correctly.I dont know if you have read about my hook in my hull. :chilipepp Ive posted about this before it really keeps the boat riding flat and slows me down. :(