hydromotive Q-4 vs bravo 1

[over board]

I am running a 27 pitch hydro. Q-4 @ 5200 rpm. I have seen 78.5 mph on gps. I have been told that a bravo 1, 4 blade is a faster prop, I have tried several mirage's and a turbo they were 3 blades, but liked the quad 4 the best. Any opinions?

 

[over board]

I am running a 27 pitch hydro. Q-4 @ 5200 rpm. I have seen 78.5 mph on gps. I have been told that a bravo 1, 4 blade is a faster prop, I have tried several mirage's and a turbo they were 3 blades, but liked the quad 4 the best. Any opinions?

 

[Dave's ZT260]

Some specs on the boat and motor would help. But generally speaking the hydromotive is very stable at high speeds 75+ but not as fast. Did the mirage make the boat unstable? It should run faster, but it could be a handful. Do you have hydraulic steering?

Scotty, I need more power!

 

[over board]

my motor is a 454 mag efi mp with a m1sc pro-charger running 6 lbs. of boost, on the gauge, also have inconel exhaust valves and fel-pro marine head gaskets and arp bolts. also a arizonia speed and marine extrude hoaned lower intake. My ecu was reprogramed @ persision marine in LA by Mark Booze. My rev lmiter is set to 5400.
You are right. The boat was a hand full with the mirage, compared to the Q-4. I plan to install ext steering this spring. Is the bravo 1 faster than the Q-4? witch one responds better to labbing? I saw on this site a guy with a 253 who lost 4 mph when he tried a Q-4 compared to his bravo 1 (running the same rpms.) If I go with a bravo-1 and have it labbed what pitch do you think I should use? I was thinking a 30.

 

[Dave's ZT260]

Don't make any decisions until you install the full hydraulic steering system. Are you experiencing chine walk? I am assuming your running a 1.35 ratio in the outdrive given the specs you provided. The boat model would also be helpful. If you’re after top speed the mirage is the prop of choice, but you need to be able to control the boat before you can make that decision. I went though this same situation with a persuader running 80+mph. Now I’m running over 90mph in a ZT260 so I have already made and corrected all these mistakes. If you have a dyno reading on the engine that would also help. I'm figuring you must have at least 550+HP to be having this kind of handling trouble. How fast could you run the mirage before you had to back off? You will probably be running 28-30 pitch when your done but, don’t waste money on props just yet. With a little more testing I can help you pick the right prop.

Scotty, I need more power!

 

[over board]

the boat in question is a 96 253 convincer. running a bravo 1 outdrive w/ 1.50 ratio. I also forgot to mention that I have gil exhaust on it.

 

[over board]

The boat really doesn't handle bad it's just where I boat we have ALOT of confused water and my wife freaks out if the moves around to much.

 

[Dave's ZT260]

The GPS reading of 87.5 must have been a fluke. Unless you turn over 5200rpm, your top speed would be around 80mph. To get to 87mph you would have a prop slip of only 2 percent. (not really possible)

As far as speed is concerned, the mirage is the fastest then bravo then hydromotive. But the hydromotive is most stable followed by the bravo then mirage.

Put the steering on, try the mirage (without your wife) and see if it's stable enough for you. You will not believe the difference hydraulic steering makes. If it's still to wild for you, and you want more speed try a Bravo. If you like it, have it labbed.

Just be careful with the rpm. Once you know what a 27-pitch mirage turns we can select the correct prop.

I would also up your rev limiter to 5600rpm. At 5400 it might be cutting in at a bad time and giving you bad feedback. My motor turns 6000rpm and the rev limiter is at 6500rpm. Just watch the tach.

Scotty, I need more power!

 

[Brian]

Overboard I would call the builder of the motor before I raised the rev limiter. Big blocks have alot of steel swinging in them, althought I don't know what you have completly done to it. As far as props go listen to ZT260 he know's what he's taking about, he's had a few checkmate's, he know's.

 

[Dave's ZT260]

I'm not saying he should overrev the motor. Just make sure the limiter is not hurting him. My rev limiter will begin to shut down the ignition one cylinder at a time before I hit the cut off. Just don’t go over 5200rpm on the tach. The limiter is just a precaution, if the drive breaks or you get out of the water, the motor doesn’t hit 7000rpm before you can back off.

Scotty, I need more power!

 

[over board]

Just to set the record straight. I stated that I ran 78.5 on gps not 87.5. I wish the latter was true.
Well, I'll have to wait until June to try a new prop, here in mich. the is hardly off the water til then. I'll keep you posted.

 

[Dave's ZT260]

Sorry, about that. 78.5mph is a more realistic number. You’re at 13% slip, higher than I would like to see with a four blade. Do you keep the boat in the water? If so, that could have been hurting the slip factor. You might want to consider putting a nose cone on the drive over the winter, if you don't have one. Blow out will ruin your whole day, and cost you some speed.

Scotty, I need more power!

 

[Dave's ZT260]

I just noticed you mentioned June. I would get out there sooner than that. Cold air and cold water are the best times to make horsepower. I notice 2-3+ MPH when it’s cooler.

Scotty, I need more power!

 

[over board]

I have been told that adding a nose cone will make the boat "hunt" thus harder to controle

 

[Dave's ZT260]

Overboard-

It may hunt with standard steering, but not with hydraulic. Test this principle yourself, have someone hold the steering wheel while your try to move the outdrive side to side by hand. You will notice a lot of play in the drive. At 70mph+ the drive will sway uncontrollably and cause a handling problem known as chine walk.

Mercury recommends hydraulic steering on any boat exceeding 70mph. Now you know why.

Scotty, I need more power!

 

[over board]

Who makes the best nose cone?

 

[Dave's ZT260]

If you want to install it yourself, hyromotive among others makes them. Bobs' Marine in FL (800) 645 3966 will install one that's welded on perfectly strait. If it's not installed perfectly strait you will have more problems that when you began.

Scotty, I need more power!

 

[Brian]

Over Board I know BOB's sell's nose cones installed on drives with low water pick's installed and nose cones not installed, some other places you might try are Lakeland Marine 928-453-1155(www.mercspeed.com).Rex marine also sells nose cones.909-392-3722(www.rexmar.com).Good luck, and if you do it yourself make sure the thing is on there strait or you will have lots of problems.