Drive change now what?

[fixxxer22]

I have a 1993 Baja Outlaw with a 500hp. I had a 1.36 drive on it (for some reason) I was running a 24p bravo1 and it did well. It was in thee 5400rpm range. Now that i have the 1.50 I need a starting place. What prop would you reccomend and i need lots of bow lift

 

[jeffswav]

Have you measured your propshaft depth? What was your GPS speed? Doing the math you would have been at about 79 MPH. You have a similar setup as mine and I was hitting 70 MPH at 5000 RPM with 25p mirage labbed for my boat. I could hit 69 MPH at 5400 with a non lab 23p mirage. I changed my x this year and I am not sure if I will be able to use my mirage, may have to switch to Bravo. I will not know until I try it.

 

[jeffswav]

Try this website. http://www.rbbi.com/folders/prop/propcalc.htm

 

[ThrottleUp Props]

Its about a 10% difference in the prop pitch so you will need to run about 26PBravo I propeller.

Julie

 

[fixxxer22]

Its about a 10% difference in the prop pitch so you will need to run about 26PBravo I propeller.

Julie

I was thinking a 26. thank you for the info. i will look for one to start at. anyone got a RH with the flo torque hub?

 

[fixxxer22]

Have you measured your propshaft depth? What was your GPS speed? Doing the math you would have been at about 79 MPH. You have a similar setup as mine and I was hitting 70 MPH at 5000 RPM with 25p mirage labbed for my boat. I could hit 69 MPH at 5400 with a non lab 23p mirage. I changed my x this year and I am not sure if I will be able to use my mirage, may have to switch to Bravo. I will not know until I try it.

Got 71 on a gps handheld with little gas and good chop water and it took a really long time to reach it. bet it is running around 65-68 for normal running with other people and more fuel

 

[fixxxer22]

I was told that the b1 24p is actually 23.5 pitch though. I have a mirage 25p and it did not like the 1.36 drive. Only could get 4700 rpm in it wiht a good ammount of gas and alone.

 

[ThrottleUp Props]

All Bravo I props are one inch less than stamped. So if your running a 24P Bravo I then you will need a 26P Bravo I with the new gears. Or in a 3B you will be in something like a 27P ish Mirage Plus. (This is not the same as a Mirage)

Julie

 

[fixxxer22]

I have had a hard time getting enough bow lift to keep from a pourpoise (if that is how you spell it) Do you think that im going to gain speed to push through that with the 1.50 drive and the 26p bravo 1? i was told that the Mirage will produck more bow lift and be a little faster but harder plaining. and the B1 is a better all around prop wit good bow lift and better plaining. I did find a way to trim through it. i would get on plane then run the drive up until the prop let go. then i would drop the drive until it grabbed and then throttle up from there.

 

[fixxxer22]

All Bravo I props are one inch less than stamped. So if your running a 24P Bravo I then you will need a 26P Bravo I with the new gears. Or in a 3B you will be in something like a 27P ish Mirage Plus. (This is not the same as a Mirage)

Julie

And if they are one less on the B1 models wouldnt i want a 25p mirage plus then?

 

[bajabob 718]

i got the same boat but it 1988 i have 540dart 624hp last summer i put both drive on i like 136 and i run a reg mirage not a plus 23pitch .i am runnig in the low 80mph on gps . the mirage is the best prop for your boat . bob teague put a 500hp in the baja with a 150 drive 23mirage prop did 68 mph at5100rpm. now powerboat mag did your boat brand new the same boat you have came with 502fuel inj 136 bravo drive 21mirage at 4900rpm it ran 69mph. just from my testing i put the 136 drive back on and run the 23mirage . i f you are runnig to 150 i put the 25mirage and twik it to your max rpm ? my motor was dyno .so i prop my boat 5500rpm 3000rpm she doing 40mph i hat it up to5600rpm 83.6 . all i no is i did all the things you are trying now and this is wt i came up with no bs i hope i help you :cheers2:

 

[jeffswav]

I am not sure how you could have possibly turned a 24p prop with 1.36 ratio to 5400 RPM. Your tach may be off, or how do you know you had the 1.36 ratio. Your boat should run the fastest with the Mirage prop with double "Baja" cup, this holds the bow up, reduces blowout, lowers slip at the high trim angle. This will also cure that porpoise problem you are having. The Bravo props are better for boats with a higher x dim. The next thing you need to know is what is your target RPM? I assume you built the engine with forged internals so this is mainly determined by your cam. If your target RPM is 54-5500 then a 23p mirage, if your target is 5000 then a 25p would work best.

 

[bajabob 718]

I am not sure how you could have possibly turned a 24p prop with 1.5 ratio to 5400 RPM. Your tach may be off, or how do you know you had the 1.36 ratio. Your boat should run the fastest with the Mirage prop with double "Baja" cup, this holds the bow up, reduces blowout, lowers slip at the high trim angle. This will also cure that porpoise problem you are having. The Bravo props are better for boats with a higher x dim. The next thing you need to know is what is your target RPM? I assume you built the engine with forged internals so this is mainly determined by your cam. If your target RPM is 54-5500 then a 23p mirage, if your target is 5000 then a 25p would work best.

jeff i agree with you:iagree: i put a 24trubo prop on my boat 4900rpm and i ran 75mph. if he had 136 drive i can t see him trunig 5400rpm with that prop ?????INLESS HE HAS MORE PONYS THEN HE THINKS??????

 

[fixxxer22]

I am not sure how you could have possibly turned a 24p prop with 1.36 ratio to 5400 RPM. Your tach may be off, or how do you know you had the 1.36 ratio. Your boat should run the fastest with the Mirage prop with double "Baja" cup, this holds the bow up, reduces blowout, lowers slip at the high trim angle. This will also cure that porpoise problem you are having. The Bravo props are better for boats with a higher x dim. The next thing you need to know is what is your target RPM? I assume you built the engine with forged internals so this is mainly determined by your cam. If your target RPM is 54-5500 then a 23p mirage, if your target is 5000 then a 25p would work best.

I could sometimes see 55-5600 on the tach if i let her wind up. I tried to make a 500hp. Had to bore it due to staining in the bores. so she is a 509 now. Has the 500hp intake and carb. has a 525efi cam in it. and some other goodies. 540hp dyno

 

[fixxxer22]

I am not sure how you could have possibly turned a 24p prop with 1.36 ratio to 5400 RPM. Your tach may be off, or how do you know you had the 1.36 ratio. Your boat should run the fastest with the Mirage prop with double "Baja" cup, this holds the bow up, reduces blowout, lowers slip at the high trim angle. This will also cure that porpoise problem you are having. The Bravo props are better for boats with a higher x dim. The next thing you need to know is what is your target RPM? I assume you built the engine with forged internals so this is mainly determined by your cam. If your target RPM is 54-5500 then a 23p mirage, if your target is 5000 then a 25p would work best.

Keep in mind that the 24 bravo is a 23p. The drive is stamped 1.36 and its for sale. my traget rpm is 54-5500.

 

[bajabob 718]

i could sometimes see 55-5600 on the tach if i let her wind up. I tried to make a 500hp. Had to bore it due to staining in the bores. So she is a 509 now. Has the 500hp intake and carb. Has a 525efi cam in it. And some other goodies. 540hp dyno

540 hp is good what speed did you get5600?????

 

[fixxxer22]

71 gps. mostly gets like around 65-68 i would assume with people, beer, toys, and fuel.
I never did like the 1.36 it was poor planing, harder on my engine and bad with a load. I did not have enough power to push that 1.36 Many Many Many people told me to get rid of it to improve my boat on all of those problems ann increasing my top speed. Even Mr. Gadgets said that the 1.36 was an incorrect choice for my boat.

The speed run of the boat was when i saw 5500-5550-5600 on my crappy fariah gauges. Jeff may be correct. I do have a complete set of livorsi mega rim gauges to install before the start of my season. The tach seems to agree with my $400.00 digital snap-on timing light with tach. I have not taken it up to that rpm but they were in agreement at 3500rpm for checking my advance.

Now, Bob I am not trying to poo poo the 1.36 I feel as though that i do not have enough nut to push that thing. But since you like it so much lemme know if you blow one up..... I may just have one waiting for you:cheers2:

 

[bajabob 718]

I dont think that a 136drive the rpm and prop your are runnig you shuold be in the 71speed.trun the shaft 1 full trun on your drive and then see how many trun the prop shaft truns??? They no way you are trunnig a bravo i 24 prop 5500rpm with 136 gears . A 24BRAVO PROP IS A 25PITCH 3 BLADE NOT A 23! PS I HAVE 1600HOURS ON MY DRIVE I MAYBE LOOKING FOR A DRIVE :cheers2: GOOD LUCK

 

[fixxxer22]

the drive is for sure a 1.36 and the prop is a 23. the bravo1 likes to lie to us. and like jeff said i may have a bad tach but i doubt it. And it will be hard to decifer 1.36 of a turn to a 1.5 of a turn. I know it is incorrect. Brett at bblades reccomended me a 25-27 pitch prop last year and i told him i had a 1.36 he said the B1 24 would work. I own a 25 mirage and it was awful on the 1.36. I am 100% certain that it is a 1.36 the boat hit a little over 70 with a bravo1 24p on it and it was for sure turning over 5k rpms. 1/8 tank of fuel no passengers no cuddy no proti potti no stereo so cushions just ropes, fenders, saftey equipment, garmin and me in a vest. My boat is like a poker run edition i stripped the cuddy to help the bow lift

 

[jeffswav]

I would say you have a erratic tach. I have the faria gages also, sometimes I get a high reading and I can tap on the dash and it drops back to normal. I would try the 25p Mirage you already have. See what that does then bring the thread back up and post your results. A 23p Mirage may be better to get you in the 54-5500 RPM range. I would look for consistant speeds of 68 to 69 with normal conditions, on a lucky day you may see 70 or 71. Now all we need is some good weather.