HELP!! prop for a 28 scarab with a blown 525sc????
 

Hey my buddy just got his 28 scarab that had a 454 in it and he has now just put a 525sc motor with a teague superchiller and blower on it running 7lbs of boost and has a bravoI drive with 1.36 ratio in it. He currently had a 4 blade 20pitch prop but theres no way that'll work now. and suggestions will help I'm thinking a 3 blade 24 or 25? possibly a 5 blade?? thanks!

i have a 24baja 540dart with 622 hp 136bravo drive i was runnig a 23mirage prop at 5600rpm runnig over 80mph. i just had the motor redone bigger cam and head work i am going to try a 25mirage prop .they work the best for me . i try 4blades do not like them on my boat hope that help you

Ok thanks for the input.

anyone else have anything close to this setup??

I have a 28' scarab with a 540 making around 645hp. It has an XR outdrive with a 1:50 ratio. I am currently running a labbed 28 Bravo and getting about 80 out of it. I know your ratio is different but the boat and power is similar. You can do the math and figure about what prop would work best for you with the 1:36 outdrive. Hope this helps some. p.s. with that power be careful with that Bravo.

Only one thing to do...........bolt on what you can and get a base line. Post that, we will have the answers to do exactly what is needed. Let's not guess. Let us know if you want to test any of our propellers.

Brett

I would start with a 24 or 26 Bravo 1. Those should be about 72-80mph props with proper slip and a 1.36 at 5200rpms.

I have a similar set up in mine.
28 Active Thunder with a 502, dart heads, cam and Procharger @ 7#
XR with 1.5 ratio Max 5 blade 28P untouched
The boat so far runs 87 GPS.
The ratio is the factor for your set up. It will require a special set up.

My buddy tried my 26p 4 blade bravo prop and said at full throttle it was at 3100 rpms? He put his 20p 4 blade prop bak on and ran 5100 rpms at around 60mph? Something isn't making sense. Can anyone help?

are you useing a gps for speed???????the other thing i would use is 3blade prop . wt is your red line on that motor if it 5200?i try 21mirage .now if its 5400rpm i try a 19mirage . with i 136 drive you have to you a small prop . like i said i run a 23mirage at 5600rpm and i am runnig over 80mph all the time i ran a 21mirage at 77mph i ran a 24pitch only got 4900 rpm 72 to 75 tops no good .i put that 23on my rpm went to 5600 and the motor runs the best . so the only thing i can tell you is look what your red line is on your motor prop it at that rpm and use a gps for your speed if that dont work then you got maybe fuel promblem ??