More top end??

[Jay Gadsby]

Hey gents, I have an 86 pachanga with a 350 alpha one set up (22 foot). I have a 14.25 x 21p aluminum prop on right now. My top speed gps confirmed is 52 @ 4700rpm with a full tank (63 gal). I may be answering my own question, but I was thinking about running a Quicksilver mirage 23p. I know stock is 14.75 on the pachangas, and I am assuming its a right hand pitch. Anyone have any experience with this? Good bad or ugly? Thanks guys!

 

[CIRRHOSISOFTHERIVER]

With that motor package that is about all your going to get. YOu may gain a MPH on the top but lose it out of the hole. Try it for the heck of it.

 

[EricW]

You will lose a ton of WOT RPMs going to a big SS Mirage AND bumping up pitch 2 inches. The bump in pitch will drop RPMs about 300, and going to the Mirage will drop another 100-200. A 23" pitch Mirage should only let your motor get to 4200-4300 rpms.

A 21" Mirage should give you about 4500 rpms and give you a decent speed increase. The Mirage has a big diameter and large blade area, and slips a lot less than what you have now.

A 19" Mirage might work well too --- it will likely let your motor hit 4800 and should give a decent speed increase as well.

A 21" Vengeance is another option. You'll hit the same 4700 rpms, and should see a speed increase due to SS thinner/stronger blades and less slip.

I don't think any 23p prop is a good idea. You're already hitting a good WOT RPM number.

 

[Jay Gadsby]

The RPMs I post now are about 4900ish at WOT, so obviously a little more prop could help. So a larger diameter prop with the same pitch would be more helpful? I will have to shop around some now. It is sad that the 350 isnt enough to push it farther up in the speed range, but I plan on addressing that this winter with some engine upgrades.

 

[EricW]

An SS prop of some type will definitely get you more speed. A Mirage in the same pitch will possibly get you more speed and DEFINITELY drop RPM's due to larger diameter/more blade area. The Mirage will bite hard and provide a lot of traction.

Since you now are hitting 4900, a jump to 23" pitch might be a good idea -- but NOT a 23" Mirage. If you want to try a 23" pitch, get a Vengeance or Silverado.

So, based on your new 4900 WOT number, I suggest 2 props to try:
13.5x23" pitch Vengeance or Silverado OR
15x21" pitch Mirage or Thunderbolt

Both should be an improvement, but I can't say for sure which one will perform the best.

 

[Jay Gadsby]

Well I opted to try out a 23P 13.5" SS Vengeance Prop. It will be here tomorrow and I will post results afterward. Thanks for the info!

 

[Jay Gadsby]

Prop is in, installed and going to be tested on the lake tonight

 

[EricW]

Sounds good, I hope the results are good. Maybe 54 mph on GPS and 4500 on the tach. Keep me posted!

 

[Jay Gadsby]

Eric, I was quite pleased with the prop. I topped out at 58/59ish GPS with 4700 on the tach, pretty spot on The conditions could have been better, there was a head wind one way, and the current flowing the other way, so either way I had a pull on the boat lol. I also have 5/8 tank of fuel as well. We will see about getting to 60mph GPS soon

 

[EricW]

Wow. 6+ mph improvement on the top end! Yeah, knocking on 60 now. Way more than I would have guessed. Pretty much perfectly propped now. I bet that much of a difference was really noticeable without even looking at the GPS. You must have been smiling ear to ear --- I know I would have been!!

 

[Jay Gadsby]

Wow. 6+ mph improvement on the top end! Yeah, knocking on 60 now. Way more than I would have guessed. Pretty much perfectly propped now. I bet that much of a difference was really noticeable without even looking at the GPS. You must have been smiling ear to ear --- I know I would have been!!

It is a huge difference for sure, the whole package is revamped (cornering, planing, top speed). I am definitely a happy man now Thanks for the advice Eric!

 

[EricW]

No problem. Glad it worked out. Dammit, now I kinda want a Pachanga 22!!

 

[Jay Gadsby]

No problem. Glad it worked out. Dammit, now I kinda want a Pachanga 22!!

I wanted one for a long time and finally got one of my own, here you see mine on top and my parents boat from when I was younger on the bottom I guess I am a Pachanga Enthusiast lol.