Lab My 242LS Prop???

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06-10-2008, 10:05 PM

#11

hoozeyurdaddy

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Quote:

Originally Posted by chewymalone

I have a 1990 Formula 242LS with 454 magnum (365HP)/Bravo 1 power. I'm currently spinning a Mirage (not +) 23P. WOT gives me 4400 RPM at 55-56 MPH. The boat is slow to plane with a load but otherwise rides and turns great with my current set-up. I would like to get into the manufacturer's recommended WOT RPM range of 4600-5000 and gain some speed doing it.

From what I've read, I might be able to cure the planing problem, increase WOT RPM's, and increase my top-end by labbing the Mirage. Any advice? What props are other 242 owners running?

For what it's worth, I also have a 23P Rapture that I'm thinking of trying this weekend. I kept it when I sold my Baja and I'm thinking what the heck. Anybody compared Mirages and Raptures back-to-back?

If you lab the 23P Mirage, you may gain about 2-300 rpm, that will give you a speed increase, but may cost you on cruise, A 21P will give about the same rpm, It will improve hole shot, get the engine closer to it's operating rpm, but will stay about the same on speed, maybe alittle less. If you have the raptor, try it, what do you have to lose, all props are different, its not the quality of the mirage, but may perform for you. No offense Julie. But am I correct on my thinking?

06-10-2008, 10:19 PM

#12

hoozeyurdaddy

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Quote:

Originally Posted by Monaco20

Hi
I have a 242 SS 454 genv 330 hp with mirage 17P , the prop is to small. Rpm is to high
So I was am looking for a new propp, I was thinking of mirage 21P-

Today we where 5 adults and 2 13 year olds teenagers.
7 people, and I struggeled to get tha boat to plane, even with the 17 P prop. I got it on plane without using tabs but it took
some time*S*

Maybe the mirage 19P will be the correct prop for me??

What do you guys think??

I have two copy of tests on the 242 LS with mag 454

Powerboat Magazine:
Quicksilver mirage 14 1/2 x 23 5000 rpm Radar top Speed 57
(Speedometr 59 mph)
Motorboat (Magazine):
Quicksilver mirage 21 4900 rpm (speedometr 60 mph)

What I find very strange are that the 23 pich has higer rpm then the 21????

I will asume that the Test in powerboat mag is the most reliable of the two

If anyone would like two have a copy of the tests i can send by email.

you need to prop for how you use your boat the most, 7 people with fuel is a good size load, is that your normal boating trip? what was the rpm then? you say it's to high, how high is that? as far as the tests go, was it the same boat? alltitude? air temp? water temp? dry climate, Humid climate? These all make a difference on propshaft HP, Look at them as a starting point and go from there, Each boat and how that boat is used is different, use the tests as information, not for how yours should be set-up.
Larry

06-12-2008, 07:47 PM

#13

cliff3466

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I have a 1989 242LS I just replaced the 454Mag with a 454Mag MPI. I just tested a Bravo 1 24P last weekend. It was a little slow out of the hole but I saw 65mph (speedo) 5mph faster than my old motor with a 21P Mirage. I have my old Mirage on eBay if you are interested.