prop ?
 

36 spectre cat what prop is everyone turning on here with 600 hp around there ..

example 34 b1 labbed is this a good starting point.

Seems as if a 34 Bravo 1 with the diffuser cut off is best. Brett at B-Blades knows the recipe if you want it labbed correctly. The 36b1 is a good kilo prop if labbed but the 34 is best all around.

I have 575 SCI with Arizona Speed and Marine pully and reprogram of ecu. I am running 1.35 gears and stock 36P Bravo's with 1/2 to 5/8" of diffusers cut off. Running 120 MPH on GPS at 5600-5700 sometimes on rev limiters. With Sportmaster lowers. Standard XR's with nose cones were at least 5-7MPH faster, but lower cases cracked around retainer rings. Just got a lab set of 36 bravos back from BBlades with more trailing edge cup, but it got too cold to test them. I am hoping to regain some lost MPH.
Gary

props
 

Thank you to all i will start with 34 b1

dumb question but what is stand xr with nose cone.

I have an xr with speedmaster lower i think .. the bottom is metal finish with nose cone..
i'm new at bravo's

would you guys spend an extra 1500 per motor to gain 40hp a side and go from 600 to 630 tto 640 dyno..

I think Gary uses Hydromotive nose cones on stock xr lowers, but the cases crack. Thats why he uses sportmasters.

Yes I think they were hydromotive cones. They were installed at Spectre. Sportmaster lowers are plain metal finish and a thicker casting than the standard painted XR lower. More mass, more drag=less speed, but are stonger. All XR upper cases are the same with different gear ratio selections and some updates done to the newer ones, such as a new top cap design. As for spending the money. You wouldn't want my financial advise. :drink:

The extra hp will be worth the extra expense,the 36 spectre loves 650-700hp the extra power helps the boat run thru the mid range porpoise in flat water,just give it some gas flattens right out,you don't want to run the boat porpoising long as it loads and unloads drives,drive reliability won't be any different from 600 to 640hp just need to learn how to run a cat with bravos.I had one 36 spectre with 600 hp ran about 115, we built several with 650+ spectre 36 a lot more fun and all seemed to run at least 120 with awesome acceleration running 1.36 with bravo 34 props turning around 5900-60000,Garys boat was the fastest one which ran close to 130 with my 650hp,the original owner wanted merc power so i installed a set of 575 mercs in it.

thanks for everything

going find the power ...

dyno
 

well went the engine shop today . it was great
motor ran great put dart intake and 1050 great power 642 hp 5500 rpm nice i'll take it.. there a catch no sea pump or alternator belt .. should this be a good 25 ponies extra.

all my test have been no alt or sea pump..