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bajabob 718
04-07-2010, 11:31 AM
this is a 1992baja with 136 bravo drive runnig a 21pitch prop from the factory. so if they put a 23pitch trunnig5600rpm .how fast do you think you will go??????:cheers2:

ThrottleUp Props
04-07-2010, 01:06 PM
Based off the original data report with 1.36 gears, 21P propeller at 4900 RPM at 69 MPH the boat has 4% slip. So that being said a larger pitch propeller will spin less RPM approx 400 RPM less than the 21P propeller. But if you just looking to get a theoretical you would use the same slip (unrealistic as only cats are capable of that low of a slip number or percentage). But even so if you could get a 23P to spin 5600 with the same 4% slip you would see 86 MPH.

My .02 cents!

Julie

bajabob 718
04-07-2010, 04:10 PM
thanks julie i put this up because some guys said they dont run the 136gears this is what i have i put a 540 dart motor pumping 622hp last year and i was trunnig 5600rpm with 23mirage .i dont think these guys beleave me ? i find my old powerboat mag .so i thouth i post it . now i had the motor redone again with more ponys :cheers2:

fixxxer22
04-07-2010, 05:02 PM
Hey baja bob.... That magazine... think you could scan that whole article and send it to me.. That is my boat! (well kinda) its neat to see it brand new in the pages of a magazine. You wouldnt happen to have it in the 1993 version would you? anyways that is a 1992 24 outlaw and the only pic is the interior. would be cool to see the rest.

fixxxer22
04-07-2010, 05:06 PM
i see it says 69 wow. mine came with the 502 and th 1.36 and she went 61 on gps. must have been tired. hmmmm i thought it was weird to have the 1.36 on it but i guess they came that way.:cheers2: i still cant wait to see what the 1.50 does:cheers2:

bajabob 718
04-07-2010, 06:55 PM
i see it says 69 wow. mine came with the 502 and th 1.36 and she went 61 on gps. must have been tired. hmmmm i thought it was weird to have the 1.36 on it but i guess they came that way.:cheers2: i still cant wait to see what the 1.50 does:cheers2: thats cool i try to tell you .i found my mag on that boat i have a nother one i cant find it . i will try to copy this for you . it took me a long time to do this . and remember the mirage prop works the best for this hull . i try all kinds of props on my boat so safe your money and buy a mirage prop good luck :cheers2:

bajabob 718
04-07-2010, 07:04 PM
try this

ThrottleUp Props
04-07-2010, 08:23 PM
Except there is one problem with this....Vee Bottom hulls are not capable of 4% slip.

Julie

bajabob 718
04-07-2010, 08:45 PM
julie i did get 80mph all the time with 75gallons fuel and 4people and 84.6 good day2people on the gps that was with 622hp :cheers2:

ThrottleUp Props
04-08-2010, 07:29 AM
At what RPM?

Julie

bajabob 718
04-08-2010, 09:23 AM
5600rpm . i n 3 weeks i will be tested my new motor . i cant wait . i will post the speed i get from that motor

fixxxer22
04-08-2010, 09:37 AM
That article is pretty cool. like stepping back in time. Thanks for posting it.

with that 1.36 on my boat and the 23 with 500hp and running 73 my slip is 19% so good deal on getting the low numbers.

I still have the 24 (23) bravo 1 and i also have a 25p mirage plus. hopefully it is enough prop. Rm builder estimates that i will now have between 560 and 570 hp and i really want to send one out for labbing. so hopefully i ave a good prop.

ThrottleUp Props
04-08-2010, 10:10 AM
5600rpm . i n 3 weeks i will be tested my new motor . i cant wait . i will post the speed i get from that motor

If that was with the 23P, 1.36 gears, 5600 RPM at 84.6 you then have 6% slip which is as low as it gets for a Vee Bottom boat. You sure about all your numbers....we usually have to run at least 5B props to get slip numbers that low.

Julie

PS: If all your data is correct I would recommend that you not change a thing because it just isn't going to get any better than 6% slip in the real world. Let me know how things go with the new motor.

bajabob 718
04-08-2010, 02:54 PM
julie yes this is wt i came up with . there is one thing i run in the river so my top speed changes with the tide and wind . now i am going with the wind and tide wish help me get that speed . i get 80mph all tjhe time .i will post my new motor soon thanks bajabob

bajabob 718
04-08-2010, 03:10 PM
That article is pretty cool. like stepping back in time. Thanks for posting it.

with that 1.36 on my boat and the 23 with 500hp and running 73 my slip is 19% so good deal on getting the low numbers.

I still have the 24 (23) bravo 1 and i also have a 25p mirage plus. hopefully it is enough prop. Rm builder estimates that i will now have between 560 and 570 hp and i really want to send one out for labbing. so hopefully i ave a good prop. thats good you got Rm builder to help you he very good makeing horse power. with that hp you are going to run good. 1 would start with the 25 and see wt numbers you come up with . then have julie twek your prop to your rpm that you want to run ? like my motor is set up for 5600rpm that work the best for my motor . good luck :cheers2:

Real Baja
04-08-2010, 05:46 PM
My math was incorrect. sorry! Used 23 not 21 pitch, my bad.