throttleup

The quad IV tends to lift the stern more than a Bravo 1. There are some boats that like stern lift and some that don't. Those that do like stern lift benefit from prop that lifts the stern. Fountains typically like stern lift and for many years came from the factory with Hydromotive Quad IV's on them. There were reasons that Fountains started to come from the factory with Bravo 1 props but it wasn't because of an increase in top end, we won't go into that any further.

The 35 likes the stern lift and that's why you will get a better top end speed with the Quad IV. There are disadvantages with the Quad IV compared to the Bravo 1. Usually the Bravo 1 gets on plane better and has a better cruise speed. Sometimes the top end speed can be made up by lab finishing the Bravo 1. The problem with that is you will lose some of the cruise speed and the plane-off ability and the lab finishing will cost you almost as much as a set of Quad IV's so what's the point. Just buy a set of Quad IV's and you have two sets of props. One for top end and one for cruising. The Quad IV's can be worked to get a little more on the top end as well.

Due to the different blade geometry of the Quad IV and Bravo 1 it's not really practical to expect both props to perform equally well on all boats. Each prop will have it's strong point.

Also keep in mind that Mercury has to make a prop for the masses. The prop needs to work, out of the box, on everything from a 22 Baja to a 36 Spectre and everything in between. The Bravo 1 prop has done that, it has to be the most versatile high performance prop on the market. It can't be expected to be the fastest prop on every boat made.

Matt

Rebel_Heart

Matt - thank you for the explanation, specifically to our boats. What is your trial and exchange program? What are the costs, etc? How long can you test try a prop because I was thinking about going to shorties, depending on how the standard length bravo perform? Thanks.

throttleup

We have a full line of Bravo I props for testing. We have some Hydromotives for testing. The program is quite simple actually.

There is a $100.00 fee for joining the program which is placed on your account as a credit to be used towards the purchase of new propellers. You pay for the shipping of the test props to you and back to me. You will have a pre-determined amount of time for testing with a due back date allowing others to test.

Julie

mmwalters

Julie I am working on a 96 42' fountain with triple 500 carb motors currently running 29'
mirage 3 blades What is your recommendation hydro's or bravos? thanks

Ran-Dom 32

My .02 is to try & see what works on YOUR BOAT - my '99 35 Single step came with 27 Hydros & swapped to 28 Labded B1 (from Throttle-Up BTW) & gained solid 2 MPH top end. I'm currently running -2 lowers & 30P B1's (stock) this seems to work well in my situation. Again the only thing I recommend is taking your GPS along & testing.

RaggedEdge

Thanks Matt. To take this to the next level let me tell you where I am now with my present props.
1) 26 stock Hydros - 5300, 81/82mph,solid top end maners,a little slip with heavy load when breaking over.
2) 28 Bravos,Lab by Merc Racing - 5300,81/82mph,not quite as solid on the high end,Great cruise and low end maners. The better of the two as all around props.
3) 28 stock Bravos - 5000, 80-81mph,just so-so all around. Act like Bravos, just not as good as the Lab set.

Questions:
1) What can be done with the Hydros for more speed ? They are my favorites in rough water and at speed. Or do I need to start with maybe 28's and work from those ?

2) In that there is some RPM potential in the stock Bravos, what could you do with them ? That would make them better than the generic Lab work done by Merc Racing.

3) What effect does cutting the diffuser off have on speed and handling ? This is obviously only in respect to the Bravos.

4)This one is for a few that are in the same position of considering the short drives. Which props would work best in that scenario ? Based on your experience.

RaggedEdge

Have we been deserted by the prop wizzards on this one ?

throttleup

It's hard to tell what could be done to the Hydro's for more speed until we see them. If they are stock there is some speed potential there. It also depends on how true the Hydro's are now. This is true with any prop. The performance results are going to vary depending on the condition of the props prior to working them. If the Hydroo's happen to be a very true set of props you will see less of a speed gain than you would if they were a set of props that were not true.

The Hydro's could be up pitched depending on their current condition. You would not need to buy a set of 28's if your current ones are up pitched.

As far as your stock Bravo's there is some potential for speed. Generic Merc lab props vary from prop to prop so it's hard to say exactly what speed gain you would see if we were to lab finish them. I will never tell a customer that they will gain a certain amount of speed based on prop work. Our philosophy has always been to under promise and over deliver. It would help to see both the stock Bravo's and the Merc lab finished Bravo's. This would give me an idea of what modifications to your stock props would work best for your application.

The diffuser ring, in your application, could be cut off with some potential speed increase. The main purpose of the diffuser ring is to help the boat get on plane by reducing the prop ventilation (blowout) when getting on plane. If you have no problems getting on plane with the Hydro's with no diffuser ring you shouldn't have any problems with the Bravo's and no diffuser ring.

As far as shorties go on your boat; you have good performance numbers now. I don't know how much more speed you may pick up if you sent to shorter lower units. This would require an in depth conversation where I could get a lot of data from you regarding the boat.

Matt

mmwalters

Matt what about your OLD Buddie here 42 fountain 1996 step bottom triple 500 carb motors currently 29' mirage props what is the best 4 blades?

throttleup

Mike,
You may be an OLD buddy, but your not OLD.

Your boat also does well with the Quad IV props. It probably came from the factory with Quad IV's on it. The Bravo 1 really is a nice prop for cruise speed. If you don't mind losing a couple on the top end the Bravo ! is a great all around prop on your boat.

PS. will we see you at any of the races? Sarasota?
Matt