SUCCESS !!

[BULLET FAN]

To add to the success thread! I did a little experiment with the Hydromotive P-5 prop that I sent back. After a long talk and a little analysis on what has worked and what was not working we decided to try a odd modification to my 28 P-5. We cut the diameter down to 14 3/8 to see if I could turn the prop better on the bottom end and spin up quicker for a decent hole shot. Well I am happy to say it freaking worked! Not a 2-4 second break your neck hole shot but with empty wells and half tanks it was a good 5-6 second hole shot and with full wells I was getting 6-8 second hole shots. Huge improvement over past results. So it was the same or better than the 26 Bravo I had been running in tournaments. Top end was better also. Now I had crappy conditions and very short areas to push it but I did get her up to 84.8 with plenty left. It does drive very different than the Bravo FS so I have a little learning curve. I also think that i should not of had the barrel trimmed but Hydro suggested it before we trimmed the Diameter. I really think that I will get 86-87 out of the prop under good conditions. The mid range was also much better than when it was a 15 inch diameter prop. I am not sure that this will help everyone that is having hole shot problems but it was a small success that could lead down a trail of many successes and I did not lose any speed going down to a smaller diameter. I will post more results as I run the boat and get better water to push some of the limits. Cheers

Glad this worked for you!!

[happykamper]

I have a question for all you prop gurus, what is the difference in the promax pro finish and the lab finish ? i know the pro finish is way heavier built, what would be the difference in performance ? If I am running a 25.5 pro finish would I need the same size in the lab finish ? Just curious because i may want a non tournament prop or prefishing prop, you know, a go fast prop.

[alli ss]

Lab finish is thinner and a bit sharper so more fragile. It has the as ground finish for less surface tension than polished finish. They are lighter so you may can spin a bit more pitch but its not guaranteed.

[happykamper]

Lab finish is thinner and a bit sharper so more fragile. It has the as ground finish for less surface tension than polished finish. They are lighter so you may can spin a bit more pitch but its not guaranteed.

Ok , I still need to see what this prop will do, conditions have not allowed it, probably be October before i really get to air it out, still not convinced that I am getting WOT.

[alli ss]

Have you took it by a dealer to see? Do you have an advanced enough smartcraft or vessel view that you can see throttle position? Have you had a friend push the pedal down while you see if the linkage on the motor is hitting the stop and the intake butterfly is open?

[happykamper]

Have you took it by a dealer to see? Do you have an advanced enough smartcraft or vessel view that you can see throttle position? Have you had a friend push the pedal down while you see if the linkage on the motor is hitting the stop and the intake butterfly is open?

Took it by a dealer, he checked it and said it is 100%, but I had another guy ask me if he checked it to see if it was at zero when the pedal was let off, i do not recall him doing that, was told if it is not at zero then i am not getting 100 % . No on the smart craft, was told you had to hook up to the computer to verify if you are getting WOT.

[Elwood]

From what I understand or rather what Mercury Racing says.......a lab finish will turn an average of 200 extra RPM with the same pitch.

[kllr bee]

sowwenssw, A stock 250R could not have 325hp. A motor must be within 10% of designated hp by law when manufactured. Have you modified a new motor that is in warranty?
Richard

[sowenssw]

sowwenssw, A stock 250R could not have 325hp. A motor must be within 10% of designated hp by law when manufactured. Have you modified a new motor that is in warranty?
Richard

I'm aware of the 10% requirement, I've been building and running Mercury race motor's for 28 years. Its has been flashed, its not stock. The flash is by Simon Performance technology and the motor is currently 325hp. Yes, it voided the warranty. I also know that Mercury does not support the use of the flash and has been putting the squash on installing them.

[crank68]

To me a warranty is just a suggestion....I’ve been voiding warranties on my stuff for 30 plus years.....

[jr 22]

I'm aware of the 10% requirement, I've been building and running Mercury race motor's for 28 years. Its has been flashed, its not stock. The flash is by Simon Performance technology and the motor is currently 325hp. Yes, it voided the warranty. I also know that Mercury does not support the use of the flash and has been putting the squash on installing them.

Do the new v8 4 strokes have variable cam timing? Active cam timing? That is the only way I can think of to get a 75 HP increase by flashing a computer. You can't get 75HP by tweaking on fuel mixture and ignition timing alone. IMO

[sowenssw]

Do the new v8 4 strokes have variable cam timing? Active cam timing? That is the only way I can think of to get a 75 HP increase by flashing a computer. You can't get 75HP by tweaking on fuel mixture and ignition timing alone. IMO

I'm not certain on the variable cam timing, and I agree, timing is going to have to be changed to see that much of a hp increase. I'm also not aware of anyone putting one on the dyno after it was flashed to see if its actually producing the 325hp. I would think the actual gain would vary engine to engine to some degree. I'm only going by what the Simon tech told me and what a highly respected mercury race tech told me who installed it for me and who has been a member of a mercury factory race team for 27 years. I put 10 hours on the motor before it was flashed, and after the flash it was night and day difference, changed the tone, the attitude, over all made the motor much more aggressive, gained rpm's and I'm happy no matter what the actual hp gain is. I ran a highly modified 2.5 drag on the same boat for 14 years, so that's my baseline, so far I'm impressed with the v8 engine after the flash.

I would think that Simon company would be hitting pretty close to what they advertise, knowing at some point someone is going to dyno one of these things after the flash. I've considered it myself just so I know for sure.

[rocketmanjp]

Think about it like this. The 250 & 300 are exactly the same except for some minor bolt-on parts. Merc took something out of the programing to decrease the 300 to 250. The flash just puts the HP back plus adds the same they can add to the 300.

[jaxbass]

Happykamper - have you had a chance to air it out yet? What are your final numbers with this prop?

[happykamper]

Happykamper - have you had a chance to air it out yet? What are your final numbers with this prop?

No I have not, I still feel like I am not getting WOT, going to take to dealer soon to have it checked out and a couple of other minor things done. I really want to try a Max 5 but dang that is an expensive ordeal, wish I could find someone with a 25 that would let me rent it for a day.