242 twin prop selection
#13
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Re: 242 twin prop selection
I have the same boat and found that the 21P Mirage props worked the best with the alpha drives. The 4 blade props will give you too much stern lift and make the boat unpredictable. If you have counter rotating drives, don't bother trying to spinn the props towards the center of the boat, this will result in too much bow lift.
#14
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Re: 242 twin prop selection
23p mirages did not work? That has been what most shops seem to lean towards.
What are you getting for cruise speeds and RPMS and wot speeds and RPMS ? With my cleavers cruise is 35-40 @35-3800 wot 63-65 @4800
What are you getting for cruise speeds and RPMS and wot speeds and RPMS ? With my cleavers cruise is 35-40 @35-3800 wot 63-65 @4800
Last edited by twin242ls; 11-08-2006 at 08:42 PM.
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Re: 242 twin prop selection
The props I have are 21P mirage plus. My engines are massaged to 355HP. With the alpha drives non counter rotating 69MPH was achievable if you put the trim tabs down a hair. This will lift the back of the boat. The back end feels a little lite, but manageable. My boat has a hook built into it, don't know if it came from the factory like that or not. Engine RPM was 5000-5100rpm. Cruise speed is 42mph @3000, 50mph@3500, 57@ 4000, 65mhp@4500. The speed numbers are off of the GPS.
#16
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Re: 242 twin prop selection
that is a factory hook which is why I have been looking into the q4x not as much stern lift as the q4's get that out of the water and you can make some speed. So you never tried the 23p plus? or where happy with the21 and stopped?
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Re: 242 twin prop selection
Originally Posted by twin242ls
that is a factory hook which is why I have been looking into the q4x not as much stern lift as the q4's get that out of the water and you can make some speed. So you never tried the 23p plus? or where happy with the21 and stopped?
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Re: 242 twin prop selection
I stopped with the 21P Mirage plus because the RPM is right. These are and older solid hub version and are different then what is on the street now. I like the mirage plus better than the standard mirage, because it doesn't blow out as easy. I did try a laser II prop, but it gave too much bow lift and cavitated too easy when riding in rough water. I have switch out my drives to Bravo ones. The old alpha drives were worn. I didn't gain anything making the switch other than a little more reliability and counter rotation. With this setup I made a run with a set of 22 pitch Bravo ones. I couldn't turn them more than 4200 rpm @ 57mph. There was so much stern lift with these props that the boat would slid to the side when a gust of wind would hit you. Not a comfortable feeling. If you have trim tabs on your boat, get it going at WOT and tap the tabs in. This will lift the back of the boat slightly and gain you a couple mph. I haven't tried the hydromotive quad 4's on this boat. Since they are more of a cleaver style prop, they may work better than the bravo ones. My guess is 21 pitch prop would be a starting point. These props have a bigger diameter than the Bravo ones and may not cause the sideways slid I experienced with the Bravo's. I have run hydromotive quad fours before on a 31 scarab and found them to have good bite and very hard to cavitate. GOOD LUCK!