Mercury Maximus
 

I am considering trying the new maximus and was wondering if anyone had some advise? I have an Advantage 32 victory with HP 500's. I am currently running Bravo 1 30's and am looking for more top speed. Any input?

The Maximus is pretty heavy compared to the Bravo's. You'll probably have to drop a couple sizes so it may not be your fastest option.

Personally, I have not found the box stock Maximus to work well on anything. Out of the box, you are buying the raw material. They really need to be labbed for the application. Brett @ Bblades does a fantastic job with the Maximus.

Kurt

On my boat a Maximus out of the box gives better mid-range than the other props I've tried, but the top end is not there. I guess because you have to drop down in pitch. My slip (10% ?) is lower with the Max.

I'm getting a Max labbed by Brett right now. I'm expecting to increase top RPM and speed, but I'm not expecting to beat the top end I've got from a bravo.

The Maximus is just a better "everyday" prop for my boat.

The Maximus is just a better "everyday" prop for my boat.

Same here for me, great cruising prop, and the slip is lower with the maximus also, = better MPG!

My Maxs were labbed by CEP.
Dean

seanmcg,

Going from the Bravo 1 propellers to the Maximus propellers is pretty much a guaranteed cruise speed and fuel economy enhancement. How much of a increase depends on multiple variables.

Making this move can produce speed gains at the top end only if the boat has set up issues with 4 blade props. This could be X dimension or weight distribution issues.

In 2003, Dennis Cavanaugh and I wrote the original recipe for Labbing the Maximus propeller. Since that time we have created numerous versions of that recipe to be used specific to specific hulls and their current performance numbers.


seanmcg, if you are looking for more speed, supply me with the current rpm and speed at wide open throttle and we can offer some suggestions as to your options. Also, we have test propellers to help you try before you buy.

Brett

Thank you for the input/advise. I will contact you shortly.

Bb

Lower slip does not guarantee better MPG you can be lugging the motors to get that lower slip and that makes the MPG worse. My experience with them has been better cruising MPH at a given RPM but worse MPG than a Bravo at the same MPH. On my current boat stock 24p Maximus and stock 26P Bravo give the same top end, Bravo is better on MPG, but the Maximus will hold the boat on plane at a lower speed and gives more bow lift, but you hear the drives clunking a lot more than with the Bravos around the docks. I have been looking for a set of 24P Maximus that have been labbed to see how they compare.

Every application is slightly different.

However there are some generalizations you can make between 5 and 4 blade propellers. Here are some of the generalizations.

4 blade props are faster on top end. This is true if the prop is hooked up well/slip is low. This is due to less drag as there is less metal in the water.

5 blade props will have better planning ability, stay on plane at lower speeds, cruise at higher speeds creating better fuel economy and have slower top speed. This is simply because there is more blade area to stay loaded with water on the face of the blades and there is more drag at WOT.

These statements are true simply from a physics standpoint. You can't argue these statements.

However, when you through in variables like aerated bottom designs and prop depths and torque curves etc., these physical attributes can change. For instance, a 5 blade propeller will tend to have better fuel economy at 3500 rpm than a 4 blade at the same rpm in "most" cases. Especially on vented bottoms. But, if you are accelerating hard to reach the 3500 rpm range, the 5 blade may consume the same or more fuel than the 4 blade. Likewise very low slip numbers with 4 blade set ups can cause a slightly higher fuel consumption with 5 blades (kind of rare though).

Again, the physics are hard to dispute except for the fact that we are dealing with boats and motors and propellers and drives and CG's and fuel loads and people and the list goes on.
So, every application needs to be looked at as its our scenario.
This is why BBLADES has a test program. Most often, using your performance numbers and set up description, we can be spot on with 3 versus 4 versus 5 versus 6 blade performance responses. But, the test program allows the boater to try variations before buying. Using these numbers we adjust Lab Finishing recipes from a standard set of numbers to get you where you need to be. We use all the physical knowledge as well as 80 years of combined experience to get you there.

So I guess I turned this post into a little advertisement. I guess I have a habit of that. By the way, we sharpen the blades on all Lab jobs (LOL). However, there are even different level of sharpening depending on the usage. Seriously.

Thanks,
Brett

brett did my maximus props . and they destroy my bravo s .. they just plain hook up and get you there . not like my bravos that took well longer to reach top speed .. must be my boat design and my higher x demention .. they dont seem to carry my bow as well . i believe they are a better stern lifting prop . but i know chit about props .. but i like my maxies rett i need 300 rpm more can you achieve this with a adjustment ???

It looks like th epost above yours by ericwinters was edited by a moderator, therefore I believe that response was for ericwinters, not you.

Did look funny !

Correct.

OK,
So I've got Bravos now with a high X, prop shaft is 3 inches below bottom of straight bottom hull, boat is an old Fountain 8.8 meter measuring just over 30' 6" from bow to transom. Boat came back with 28' Bravo 1 and now it will not plane with full tanks and the tabs down, have to have the tabs up to get it to fall over, and it just doesn't like having so much of the prop out of the water. Thinking a 5-Blade is the way to go 28" pitch. (with deep TRS, it would pull a 29" hydromotive to 4500 and 70 mph, and at 2600 it was hooked up and efficient at 30 mph). Comments? Running about 525 to 540 HP at the props.

Good luck. As with anything changing scenarios will need adjustments. Try Brett's program on props. I'd go with more bade surface if you're cavitating. 4500 is way to low rpm. Might want to drop a couple pitches. Maximus props are big mofos ,, you might have to drop several pitches to achieve rpm levels. The real question is you're slip numbers. That will tell you what prop to run. I love my Maxie's.

4500 was with one (1) sick motor (bad rings) run on 7 sometimes, had other issues to keep it from top speed, had drive set at '3' when it should have been at '6' with TRS, good engine carb grabbed bit of gunk in the secondary needle valve cut testing short, so the 4500 at 70 was just what it got to, and did not have time to test further as it was headed to the shop on that run. With drives trimmed, running on 8 both sides, folded Bimini's off boat instead of in the breeze, it would have pulled 5 to 55 rpm easily.

Brett,

When does it make sense to remove the diffuser ring? Is this more for planning than anything? I have a 30' cat with prop shafts even with hull so they are definitely surfacing. When I went from bravos to p5-x it was night and day difference in planning. I feel simply the 5 blades had this affect. I do have porpoise at mid range now and when accelerating. Too much bow lift? I talked with Bob leach and he said I need the maximus props for best results. I asked if I should use the short tube or standard version. He said short Tube. Then a day after that I talked with a fellow member here with almost same boat setup and he went with the standard maximus with great results. Sounds like the maximus is the way to go but don't which which style. Also I believe the diameters are larger than p5-x props. If so how much more and how does this affect pitch selection when comparing the two? Would it be a wise move to lab these props to a specific boat such as my daytona or are they geared toward my type of high x boat already in either model? Thanks!!!

Eliminated572,

These are all great questions. They also require a bunch of explanation and discussion. I would request you contact me at the office to discuss this in depth. I can cover more ground quicker that way.

But until then............
Diffuser rings were introduced many years ago for through hub exhaust set ups. The divergent tube created high pressure which isn't attractive to the high pressure on the prop blades and prevents blow out upon planning.

There up pros and cons to the diff. rings. Some cons are drag, stern lift and reduction to trim reaction. Some pros are better planning and stern lift.

The Maximus is 15 5/8" diameter out of the box. The P5X is 15" of diameter.

The diffuser ring/tube was not intended to be as long as it is when we began development in 2002. This development was a joint venture between us at Merc Racing and the main plant Merc Propeller Co. In the end with the large diameter and large rake angle we needed a long diff tube to aid in production. It was that or build new pouring fixtures for the foundry. Longer tubes was the best option at the time.

We have been cutting the tubes off the Maximus since the props inception. Mercury Racing decided to offer this as a actual part numbered option a couple years ago rather than a custom option. The down side is you only have one option. We offer various lengths of removal determined by the actual set up.

I've written volumes of information on these props on this forum over the years. Search back if you have time to learn more or call anytime.

Oh, by the way, the correct Labbed Maximus will most likely out perform the P5X.

Brett

Thanks Brett! I will be calling this week. I've been trying to search and the search feature on the forum has not been working the past few days....leaving me frustrated and lacking intelligence ;) Talk to you soon

Brett will the maximus be faster than a p5 all around? not the p5x

T-Mone,

The P5 is a completely different anima than the Maximus and the P5Xl!.
We'll need to know a bunch more about your application. In the majority of set ups the answer is yes. But, every application is specific to itself.

Brett

Morning Brett, I will call you today.

Ron

Thanks for talking with me today Brett. I feel quite confident we have the golden ticket with these new Maximus props! Thanks again for your assistance. I am a previous, current, and future bblades customer!

I recently bought a set of Maximus 30p props used. They are very clearly labbed, and maybe cupped a bit? Brett, what markings am I looking for to know if you did them? They have a number stamped into the hub area that I do not believe is stock. It starts with 2 Capital B's, the first one is backwards.. is that your mark?

That is a BBlades number. Brett can look up the number and tell you what exactly was done to them.
More than likely he is busy at the boat show now.

Thanks Griff, I kind of figured as much, I appreciate you verifying!!