scarab39

what size prop should i start with? 850 hp, #6 dry sump, 1.35:1 ratio drives, 600ft elevation on smooth to 1ft lake in texas?

Orthobam

I have a set of Mercury's that sound like a great starting point

16.75 x 33 five blade

$3500

bbladesprops

16.5-16.75 diameter with pitch in the low to mid 30's depending on variables and goals.

Current performance numbers would help to make the decision.

Brett

scarab39

I'll be running 17 x 34's this weekend, I'll post results

thanks
Chris

scarab39

17 x 34's aren't enough , im at 6000 rpm too soon and 16.5 x 39 5 blades don't grab. I'm around 1200 hp with turbos. When the turbos spool up the 39's just spin out. Both props will get me to mid 130's but the 17 x34 prop works better. I'm thinking I need the the bigger diameter and more rake. Can someone suggest a prop for this boat with 1200hp ? I'm thinking 17 x 38 5 blade with about 18 rake, any suggestions / thoughts would be much appreciated

wgg

That boat with with 16.75 X37 16degree Herrings should run high 140's at 6200 RPM's
you should see 150 with 38's Assuming 8% slip Not Techs dont like high rake props

scarab39

Thanks for the info, is 16.75 preferred over 17 for this boat? It was odd how the 16.5 x39 would just blow out but I know very little about props.. Was 18 degree high and 16.5 low the reason? That's my guess anyway

bbladesprops

What props and who's props and where have they been props etc......
Didn't you say 850 HP earlier.............now we have a different level.

Now you think bigger diameter .. Your mixing stuff without learning stuff......
Stop, regroup and call me when you can.
Before you go wacko. If you haven't already.

Or. pay to play and get pissed off.

Brett

scarab39

yes, i added turbos. I have two sets of props. mercury racing 16.5 x 34 850 hp and hering 16 x 39 1200's. I like how the 34s work except I'm on the rev limiter too soon. I'm curious what other people use on their nortech 3600 with similar power. I'm still screwing around with the motors, once I'm happy with them I'll focus more on the props but in the mean time I'm trying to gather info on what others use. I went wacko a loong time ago

PRIMECUT

Listen to Brett he will get you where you need to be