More power from My 7.4MPI´s
#1
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Hi. I just went from Mirage Plus 23´s to Bravo 24´s on my 29 OL. The top speed is exactly the same, 61 miles because it wont reach 4.600 rpm with the bravos.
I did gain around 5 miles at 3.500 rpm wich is great but it would be nice to get just a little more power out of them so they reach 4.600 rpm with the bravos in an easy and sheap way.
Is that possible somehow with other exhaust or something or should I just forget it?
Sorry about my english, I´m from Sweden.
/Teo
I did gain around 5 miles at 3.500 rpm wich is great but it would be nice to get just a little more power out of them so they reach 4.600 rpm with the bravos in an easy and sheap way.
Is that possible somehow with other exhaust or something or should I just forget it?
Sorry about my english, I´m from Sweden.
/Teo
#2
Those motors are RPM limited to 4850 I think. I would expect the same speed out of the two propellers as they are both very close in pitch.
The gain you saw at 3500 RPM is typical of a 4 blade propeller. They tend to increase cruise speed more than top end.
I think that the 24p Bravo 1 would get you a few more MPH by having it lab finished, but for the HP you are running I wouldn't expect much more than 62-64 mph out of that boat with that power.
The gain you saw at 3500 RPM is typical of a 4 blade propeller. They tend to increase cruise speed more than top end.
I think that the 24p Bravo 1 would get you a few more MPH by having it lab finished, but for the HP you are running I wouldn't expect much more than 62-64 mph out of that boat with that power.
#3
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Those motors are RPM limited to 4850 I think. I would expect the same speed out of the two propellers as they are both very close in pitch.
The gain you saw at 3500 RPM is typical of a 4 blade propeller. They tend to increase cruise speed more than top end.
I think that the 24p Bravo 1 would get you a few more MPH by having it lab finished, but for the HP you are running I wouldn't expect much more than 62-64 mph out of that boat with that power.
The gain you saw at 3500 RPM is typical of a 4 blade propeller. They tend to increase cruise speed more than top end.
I think that the 24p Bravo 1 would get you a few more MPH by having it lab finished, but for the HP you are running I wouldn't expect much more than 62-64 mph out of that boat with that power.
Do you think it will drink much more gas with the bravos?
Last edited by Teo; 05-22-2011 at 05:41 PM.
#4
#5
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From: www.bajaboatowners.com
Hi. I just went from Mirage Plus 23´s to Bravo 24´s on my 29 OL. The top speed is exactly the same, 61 miles because it wont reach 4.600 rpm with the bravos.
I did gain around 5 miles at 3.500 rpm wich is great but it would be nice to get just a little more power out of them so they reach 4.600 rpm with the bravos in an easy and sheap way.
Is that possible somehow with other exhaust or something or should I just forget it?
Sorry about my english, I´m from Sweden.
/Teo
I did gain around 5 miles at 3.500 rpm wich is great but it would be nice to get just a little more power out of them so they reach 4.600 rpm with the bravos in an easy and sheap way.
Is that possible somehow with other exhaust or something or should I just forget it?
Sorry about my english, I´m from Sweden.
/Teo
It's also possible altitude or elevation is effecting it. You should be able to spin 24's with 7.4L MPI's
#6
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Thanks.
#7
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From: Northern, KY (Cincinnati) Lake St Clair, MI Norris Lake, TN
I ran 62 MPH with 23" mirage on my old 29OL with 7.4s. It would flirt with 63 every once in a while. I also had 22" 4 blades and it was quicker, but would bump the rev limiters from time to time with a light load. I think labbed 24"s would be perfect on that setup. You only need to pick up about 200 RPM.
#8
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From: Bucyrus, OH.
I ran 62 MPH with 23" mirage on my old 29OL with 7.4s. It would flirt with 63 every once in a while. I also had 22" 4 blades and it was quicker, but would bump the rev limiters from time to time with a light load. I think labbed 24"s would be perfect on that setup. You only need to pick up about 200 RPM.
#10
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From: www.bajaboatowners.com



