AppSysCons

What follows below, is my opinion, based on my testing. You should consult a professional, before attempting any of these tests or changes yourself.

This past weekend, I tried the Throttle Up CNC 14.75 x 31 4 blade props, on my boat, 30 Skater T/300XS. Compared to the 3 blade props they worked better at getting the boat on plane, quicker, easier, less vibration, they had better midrange acceleration, and wot performance, was 0.4mph faster. They do cause some additional stern lift, over 3 blade props, which makes the boat feels a bit looser, but it is manageable and water pressure is above 10lbs.

In total, we have tried 8 different propellers:
Merc Racing 14.5 x 32, 3 blade cleaver, lab finished
Merc Racing 14.5 x 34, 3 blade cleaver, lab finished
Merc Racing 15 x 32, 3 blade cleaver, double lab finished
Merc Racing 15 x 32, 3 blade cleaver, lab finished
Throttle-Up CNC 15 x 30, 5 blade, cleaver
Throttle-Up CNC 14.75 x 30, 5 blade, cleaver
Throttle-Up CNC 15 x 31, 4 blade, cleaver
Throttle-Up CNC 14.75 x 31, 4 blade cleaver

We have also tried 8 different setups:
Props turning in
Props turning out
Prop shaft height, 7/8 above bottom
Prop shaft height, 1 1/2 above bottom
Prop shaft height, 1 5/8 above bottom
Prop shaft height, 1 3/4 above bottom
Toe out 1/4
Toe 0

The best setup is, 1 3/4 above the bottom, toe 0, props turning in, and a bottom modification “water ramps” to get the necessary water pressure.

The 5 blade props just have way to much stern lift for my boat, which leave the best 3 blade and the best 4 blade prop. They are the MR 15 x 32, 3 blade cleaver, lab finish, and the TU CNC 14.75 x 31, 4 blade, cleaver.

Here are the back to back runs for the 2 best props:

Weather underground, NOAA, National Weather Service, and Weather Channel, reported the following at the time of my runs:
Air temperature low/mid 90s
Humidity 67% - 90%
Heat index 105-110

MR 15 x 32, 3 blade cleaver lab
TU CNC 14.75 x 31, 4 blade cleaver

PORT STBD AVG MPH SLIP
MR 5837 6005 5921 97.3 9.32%
MR 6025 5909 5937 97.9 9.46%
MR 5994 6009 6002 99.7 8.32%

TU 6029 6216 6213 99.2 10.59%
TU 6042 6257 6150 99.4 10.80%
TU 6072 6261 6186 100.1 10.44%

I scored each prop in 4 categories; getting on plane, mid range acceleration, wot speed, and handling, giving 1 point to the prop that won each category. The final score

3 points = TU CNC 14.75 x 31, 4 blade, cleaver
1 points = MR 15 x 32, 3 blade cleaver, lab finish

For me, the Throttle-Up CNC 14.75 x 31, 4 blade cleaver, are my propellers of choice and will remain on my boat.

Bobthebuilder

100.1 MPH - Congrats Frank on turning triple digits. I'm sure the info you posted will be helpful to others here. Interesting and thanks for sharing.

On a side note I met with 4 of 5 FMO board members last night and we will soon have a schedule of runs together for 2009 / 2010. Couple of exciting new destinations and will circulate the info hopefully with in a week to 10 days. See you on the water soon.

Bob

AppSysCons

Thanks Bob. It runs faster in the cool winters here in FL, but I guess 100 and a fraction is the best I should expect in the blistering heat and humidity.

Can not wait for the FMO season to start up again!

Here is the best run from this weekend, and one from December, with the old MR 3 blade props. I am expecting to break the old record, this winter.

marylandmark

Awesome Frank and thanks for being so diligent and willing to share.

Throttle Up- sweet!!

BenPerfected

I like your approach to maximize your top speed. The last 5 MPH is expensive...but fun! You can't stop now, what's next?

AppSysCons

I am at an honest 100mph in crazy heat and humidity, and maybe 103 in the winter here in FL (70s-80s, low humidity).

I am done fooling with this one, now it is time to run this boat and have some fun! She is for sale, now you too, can get a 'professionally' dialed in 30 Skater. The next boat will be a

Maritime_Eng

[QUOTE=AppSysCons;2918888]
Can not wait for the FMO season to start up again!
[QUOTE]

We can not wait either! I have spent all summer working on the motion making it a reliable fun boat.

Enjoy the boat Frank, it is one heck of a nice ride.

stainless

It would be interesting to see how they compare to a set of mercury racing 15x 32 4 blades that have been worked by bblades. ( They turned out to be my fav props on my old 328 cob skater)

AppSysCons

That would be interesting; however, Throttle-UP has provided me with such a high quality level of service, I would not even consider going somewhere else for props, now or in the future. They have earned my business for life.

The hi-perf boating industry can learn something from Throttle-Up in this area.

Having said that, I know that Bret also has an excellent reputation. I had dealt with him way back at MR when he was working for Dennis.

Maritime_Eng

I am running a modifed set of 15X32 MR 4 blades that are actually 31's. If you ever want to try them let me know and we can meet up at the beach and try them on your boat.