Props in vs. out
 

What's the difference between running the props in vs. out? I have a 04 35 Lightning side by side, switching to -2 imcos. I plan on trying new drives and several props turning both in and out.... But I'm not sure what to look for and not sure how each configuration affects bow lift, stern lift, getting on plane, speed and stability.

Docking and speed it the most you will notice, Spinning IN will get you more top speed, OUT less speed.... IN not good docking manners, OUT Great docking manners. I run the same set up and run mine out, I'd rather loose 3mph then put a scratch in at the dock for eveyone to see.

I chose to rotate mine "in". Better stern lift, but you do certainly sacrifice driveability and backing up around docks.

I do more alot docking than running at WOT, so I spin them out.

In is definitely faster & the boat will still maneuver well around the dock.

Spin them in, faster.. The dock thing is iffy. Yes there might be some difference, but it is not like the boat is undrivable, esp if you have half ass knowledge on driving a boat..

John jr

What about high speed stability? Could turning them in cause any issues getting on plane or chine walking?

I recently turned mine in after having them out for almost a year. To me it seems to be more stable at speed. Docking is not that different and definitely not bad. Getting on plane no noticeable difference either.

Agreed. And the handling characteristics of the boat are better as well. Far as the docking goes, once you get your head into how the boat reacts it is somewhat a non-issue. Admittedly might be a little better if turning out, but not something one can not master with a little thought. My last three boats, over more than a decade, have been turning in and not a mark on a one of them, I have more trouble now with ones that turn out.

Fountain sent them out the door turning in for a reason, and my guess would be it was not for ease of getting it back on the dock.

What effect does turning the drives in have around the dock? Would I still turn the boat around the same way?

I spin them in and docking is easy...The boat handles and feels way better..Plus who wouldn't want 3-4 mph for free!!!!

If I got .5 mph more, I would run them that way. It's probly the boat racer in me.
After mastering, docking manuvers on my 27 single and an old owens 27 cruiser single, (IN THE WIND) I feel I can do anything.

I LIKE inward rotation better, nut here the other day, I changed the rotation from out to in on a 1994 35 Lightning (non stepped) with 2x720 hp, and that boat was slower turning them in. So we switched back to OUT.. Strange?!?!?!

Call me new, but what is involved in changing from out to in? Simple answer will suffice for now. Thanks!

Just to make sure I understand in vs out. Is rotating in when your Port Prop rotates Clockwise and your starboard counter clockwise?

For a short term test you can simply change props from one drive to the other, then place shifters in reverse position to move foreward, into foreward position to move backwards. Longer term just change the cable location on the shifter unit.

This deal works on a Bravo set up, Bravos do not really know what direction they are running in.

In ..........................

Ok so mine must be spinning out. My Port prop spins counter clockwise and my Starboard Clockwise. I may look at switching mine to see how the boat reacts.
When you change the cables at the helm what exactly do you do? I have the Gaffrig 4 throttle controls. Right now I push the drive levers up to go forward. If I wanted to get the props turning in what would I need to do with the cables to get the to make the boat go forward by pushing the controls up like I do now? Do I also need to swicth the props from port to starboard and starboard to port?

Just swap the props around and leave the cables where they are for now. Forward will then be reverse, and reverse will be forward. if you like it, then swap the cables around.

On mine, I started out in and switched to out. Turning in pulls the stern down, turning out lifts the stern. On a 32 with twin big blocks, there is an awful lot of weight aft, so at everything under about 50 or so, the boat needs tabs down. Also, in rough ocean conditions here in the Pacific, the boat almost always needs some tabs down.

I found that by having the props turning in, I needed a little less tab, so it ran faster at partial throttle.

I could not measure a difference at top end, but It was easy to see the improvement at partial throttle.

Also, I found that its now much easier -- automatic really -- to turn the boat on a dime. Less radical turns are basically the same. However, moving the boat sideways when approaching the trailer to haul it out is a little tougher.

I am sure that Reggie set them up for max speed, so I'd stuck with what he did originally if you are all about max speed.

But try it: its easy to experiment if you've got Bravos.

I think you have that backward props spinning in will give you more stern lift , helps on the twins to get all that a$$ out of the water, I also run mine in , took a bit to get it right at the docks but you get the hang of it..

That's what I'm looking for. I've been trying a pair of Herring 33p 6 blades that are giving me a lot of stern lift. It want's to chine walk around 95 if trimmed up to 4 and it gets dicey past 100. When I get the -2 lowers on I want to try them both in and out. I'm also trying a pair of 5b Maximus to try and settle the stern. Hopefully with a little trial and error I'll figure out what works best for my boat.

Thanks to everyone for the input!

Mike

Spinning "IN" gives you bow lift. Spinning "out" gives you stern lift. Period.

Spinning in can substantially increase top speed on big boats, like say a old 38 Top Gun, 42 Fountain, etc. Mainly because it helps carry the nose out of the water, with less positive trim, and reduced wetted surface.

Rarely does spinning out net a greater top speed on most V bottoms, stepped or not. Spinning out made my old 38 Fever run flat as a pancake, even at top speed the hull was wet. Spinning in, is quite a bit faster, and the boat will run on its pad.

Nice numbers! What are you running for power?

Thanks!!!

Randy at Cobra just rebuilt my 525's and added Whipple's. They hit 784 on the dyno. With stock Bravo XR's we had a best of 103. Hopefully with the -2 Imco lowers and find the right props we should pick up some speed. I'm planning on sending it boat to RF over the winter so Reggie can make it really fly.

SWEET!!!

Keep us posted on the -2's. Do you know what your X is now?

Will do..... Should have some numbers next week. My X is 18.25 and I think the drives are currently around 4" below the surface