LTZCrew

2003 shockwave tremor closed bow
merc ITS with standard lenght bravo 1 XR
re worked 575sci - 825~ hp limiter set at 5900rpms

so far ive tried a labbed 28 B1- spun it right to the limiter
B1 31 pitch*labed 30* with the ring cut down - ran right to the limiter at 89mph
tried a max 5 32pRH 15.75 - wicked cruse but had to run heavy. full fuel and 4 people or the boat would act weird and you could hear the motor load/ un load over the smallest of ripples on the water and had a wicked vibration if i come onto or off plane to slow
max 5 32p LH 15' no weird vibrations and less issues with the loading/unloading but seems to have way more lift, boat wants to walk all over the place as soon as you lean on it

looking to get my slip down and break into the 90's
thinking a 34 or 36B1 is the next bet?? or can a 5 blade be worked to calm this down
seems like the 5 blades just have to much over all lift and get her to be to squirmy.

smokediver

You have a nice prop collection going ! I would throw a -2 imco on it. Especially if you added the its at the factory opening. Hate to spend your money but I would guess the standard lower is your issue , especially with the speeds you are running

LTZCrew

I was thinking a shorty. But im not sure after running the big diameter 5 blade. With how it reacted to small changes in the water im guessing i was surfacing part of it.
or was that it unloading and spinning to its desired slip?

F-2 Speedy

iTrader: (6)

Where is the prop shaft depth in relation to the hull bottom.

boostbros

what is the hull like?steps or non? can you spin the engine up to 6500? we run a bit less power but turn it up higher with stock bravo xr on a non stepped 25 foot hull it rips to the high 90s and is stable and predictable and an absolute blast to drive

boostbros

we also run a stock bravo 26p prop 4 blade

LTZCrew

ill have to measure, i dont remember off the top of my head

24* V, single small step - maybe a inch in depth no pad no notch, full length strakes(?) as for RPM never ran it up that high, Dyno shows it started to loose huff at 6k, its still using a modified TBI set up so that's probably all she can breath. there is no lack of power, i can run inot the limiter pretty hard with everything ive tried so far.
im trying to find a out of the box 36p to try but they seem to be imposable to find
is there a way to keep the 5 blade Bite and have its lift more inline with a 4 blade?

LTZCrew

Well the 32L 5 blade had to much bite. Couldn't get the rpms up. Ran 81. Didnt seem to carey the boat. Back on the hunt for a labbed 34

SecondWind

I would start with a non-labbed 34. If you want a labbed prop lab it for characteristics you desire on your boat.

LTZCrew

one thing i did notice and forgot to ask/ mention. with a 4 blade i get some wicked torque lean till i trim out - a lot. the 5blades never did this when matching speed for speed. wouldn't more blades put more "twist" on the hull?