Phantom 25 1985 - 450R
11-17-2020, 04:16 AM
#1
Gold Member
Gold MemberThread Starter
Phantom 25 1985 - 450R
Hi!
I hope everything is ok with you all.
I am going to buy a 450R next year. Currently I have a 400R on my Phantom 25. The boat runs 88-89 mph spinning a Max5 25 standard tube prop at 7,040 rpms. The propshaft is 2 inches above the bottom. In all approx 8 inches setback incl notch. The boat ran 81 mph on a good day with a 350 Sci spinning a REV4 25 prop at 6,500 rpms. Propshaft 2 inches below the bottom.
I am not sure how much gain I will get with the 450R, but if I am correct the 400R is pulling 390 HP and 450R 450 HP. So maybe 94-96 mph at WOT.
I plan to buy a Max5 27 pitch prop. What do you think? I presume its wise to test out the Max5 25 first but I expect it to hit the rev limiter hard then. Do you have other suggestions? A CNC 5 blade cleaver could also be the thrick, although its a very expensive prop. In Norway we need to buy to test ....
Have a good day.
Cheeers, Toffen
I hope everything is ok with you all.
I am going to buy a 450R next year. Currently I have a 400R on my Phantom 25. The boat runs 88-89 mph spinning a Max5 25 standard tube prop at 7,040 rpms. The propshaft is 2 inches above the bottom. In all approx 8 inches setback incl notch. The boat ran 81 mph on a good day with a 350 Sci spinning a REV4 25 prop at 6,500 rpms. Propshaft 2 inches below the bottom.
I am not sure how much gain I will get with the 450R, but if I am correct the 400R is pulling 390 HP and 450R 450 HP. So maybe 94-96 mph at WOT.
I plan to buy a Max5 27 pitch prop. What do you think? I presume its wise to test out the Max5 25 first but I expect it to hit the rev limiter hard then. Do you have other suggestions? A CNC 5 blade cleaver could also be the thrick, although its a very expensive prop. In Norway we need to buy to test ....
Have a good day.
Cheeers, Toffen
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bulletbob (11-19-2020)
11-17-2020, 06:26 AM
#2
Registered
Referencing the high cost of marine parts and products in the EU, you can use the Max5 25P as your break in/ base line prop with the 450R.
From your base #'s you can dial in closer to the proper pitch combo... may not be the perfect answer but it keeps from spending your $$$ twice on a prop with no base line #'s to begin the dialing in the bigger power
From your base #'s you can dial in closer to the proper pitch combo... may not be the perfect answer but it keeps from spending your $$$ twice on a prop with no base line #'s to begin the dialing in the bigger power
11-17-2020, 01:01 PM
#3
Gold Member
Gold MemberThread Starter
Hi!
Thanks
Good point. I will check out with the Max5 25 and see the rpm and speed. Most likely we will hit the rev limiter hard, but then we have a baseline how many rpms less we need. The peak power rpm is 6200-6400.
Cheeers, Toffen
Thanks
Good point. I will check out with the Max5 25 and see the rpm and speed. Most likely we will hit the rev limiter hard, but then we have a baseline how many rpms less we need. The peak power rpm is 6200-6400.Cheeers, Toffen
11-18-2020, 01:29 AM
#4
Charter Member # 55
Charter Member
It will be hard to tell how much you need to reduce rpm if its banging the rev limiter.
400R has a 1.75 gear ratio and 450R has a 1.60 gear ratio. Theoretically that will about 3" prop pitch difference and would equal about a 600rpm reduction with just the ratio change and assuming the same hp. With a 60hp increase, that equals about a 400-500 rpm gain. The 450R lists a WOT rpm of 5800-6400 so I think you are on track going with a 27" in the same make of prop.
400R has a 1.75 gear ratio and 450R has a 1.60 gear ratio. Theoretically that will about 3" prop pitch difference and would equal about a 600rpm reduction with just the ratio change and assuming the same hp. With a 60hp increase, that equals about a 400-500 rpm gain. The 450R lists a WOT rpm of 5800-6400 so I think you are on track going with a 27" in the same make of prop.
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Toffen (11-18-2020)
11-19-2020, 06:19 AM
#5
Registered
Toffen talk to Randy Coursen "Wildman" on Scream and Fly. He is is setting up a 2nd Liberator with a 450r. The first ran into the 120s'. They have done extensive prop testing on the 300R, 400R and should have some insight and suggestions for the 450R. Randy is a great guy and is always willing to give good advice on setups. He helped me with my Talon setup.
Cheers Bob
Cheers Bob
Last edited by bulletbob; 11-19-2020 at 06:21 AM.
11-19-2020, 07:04 AM
#6
Gold Member
Gold MemberThread Starter
Toffen talk to Randy Coursen "Wildman" on Scream and Fly. He is is setting up a 2nd Liberator with a 450r. The first ran into the 120s'. They have done extensive prop testing on the 300R, 400R and should have some insight and suggestions for the 450R. Randy is a great guy and is always willing to give good advice on setups. He helped me with my Talon setup.
Cheers Bob
Cheers Bob
Will do ! Thanks Bob !
