[mzuck]

Looking to find out which 4 blade prop I should run on my 2001 225Z CD 7.4L MPI Aplha1? I just don't seem to be getting the speed I should be getting

[mikeyt]

What prop is on it now? What are your RPM's at top speed? What is your top speed?

For a little self-education, please read the STICKYS at the top of this forum.

[badjudgement]

I will bet you Wil end up running a 4 blade 21 pitch, you will want the rpms to be between 4600 to a max of 4800 at WOT with your normal load of fuel, passengers gear etc. My 2350Z with a 454 Bravo is running a 21 mirage plus at 4700 rpm with a top speed of 53.72 mph on GPS. Your boat is smaller with the same power so I'm GUESSING that you will use a 23 3 blade or a 21 4 blade but only testing will tell you the answer.

[ColoradoDiablo]

If your after speed you need to be running a 3 blade prop no matter what pitch you use.

As mikey stated , take a look at the "sticky's" , there is lots of info in them.

[mikeyt]

"Guessing" is of no value. We'll wait for the OP's information before offering up any advice.

[badjudgement]

Agree with better speed from a 3 blade, give a 21 mirage plus a try, the plus will he he you better stern lift and more speed. This is a very popular prop so you should find someone with one that will let you try it.

[badjudgement]

You have to start somewhere and I will bet a dollar to a donut he will be running a 21 or 23 3 blade...this is not my first rodeo.

[badjudgement]

Not trying to start an argument with you mikey but if you read my entire post I state that only testing will tell the truth...I offered GOOD rpm info to him which no one else did.

[mikeyt]

This might surprise you but this isn't my 'first rodeo' either.

Your 'rpm info' is contained in the STICKYS mentioned in post #2. Before the OP wastes time & effort by guessing or testing , you have to establish a baseline by knowing exactly what rpms and speed your present prop is making before you make any changes.