In or out?
 

I know I know we have been over this a thousand times. But in just curious as to why fountains turn in? For instance in turning in creating stern lift but my boat loves trim. Hustlers turn out and is about 5' longer then my boat ( 35' fountain /388 hustler) same power. Hustler is faster? I am thinking of swapping drives but I'm looking for someone who has experienced it both turning in and out. And what power and props.

What do you have for drives? If bravos just switch the props and run in shifters in reverse. A lot of factors can figure in here. Propshaft height? Steps? 35's are fast if set up right.

Turning in creates bow lift not stern lift. I believe in is about 3 mph faster on average but a lot of people say its harder around the docks and can cause loss in stability in some boats. My donzi turns in and I think its great all around but never ran them out. I was thinking about trying it but my boat runs extremely flat with the bow lift from the props couldn't imagine how low it would run with out it.

I have 1:5 bravo factory set up. 600hp at the motor 600ish t and running labbed 30 bravo props. If I don't switch the drives forward will be reverse and Vice a versa . I know I'll slam that sum ***** into the dock. But it's a good idea just to get some top speed data. Thanks

Also you r trying to compare two totally different boats. Even if they where the same length and weight the steps r completely different. Shaft heights probably not the same so even with the same power could still run different mph. Need to compare apples to apples not apples to oranges.

The drives rotate the same forward and reverse is decided by cable movement under your shift controls. My 35 is a twin step with standard bravos p5x hydro's 550 hp ran right at 88. And I believe turning in creates stern lift.

I know you will have a lot of fountain guys getting u good info from there experience with there 35s. My donzi with 500efi's spinning 28s that are stock I see on average 78 to 80 wot and seen 83 once. If I try out and get some #s I will post it up but won't baby any time soon thow lol.

I get that much. But your talking about a pad bottom boat ( fountain) to a non pad ( hustler) boat step bottom boats an mine is small. I have 600 hp he has merc 525. I'm turning 30p he is running 32p . I will say this. I have not fully broken my motors in before winter set in. But by rights I should be seeing close to 90mph with the right conditions.if my boat is running little trim as 50-60 mph she will start porpoising unless you give it more throttle.once you brake 70 it is gone. My belief is its because I turn in?

I think it causes stern lift also. I just can't see how props turning out could cause stern lift. Turning in the props are pushing in the same center below the pad. Turning out would have the adverse effect.

What year is your boat single or twin step. Do you know where your propshaft is in relation to the bottom. What is your wot with the 30's?

Stock set up on the drives. Don't actually have the dementions for the drives. And it is a single step boat. I haven't had a chance to go wot . I was breaking it in and always had the wife and kids with me. Also ran out of summer. But that being said. Stock 35 run 85ish. Stock hustler run 88-90.

So how are you trimming your drives at various rpms and speed ?

Usually depending on water conditions I'll be trimmed to about 2-21/2 on the drives at a cruise speed of 50mph at 3100 rpms. If I trim more then that it will porpoise . But if I lay into it a little more she like a little more trim. Again this post may be a tiny bit premature due to the fact I have no wot numbers. I did run it up to 78mp at 4700rpm for a brief moment.

You might be under propped. You might wanna try a 32. You'll know better after you get some wot #'s.

You think? Not sure. Dyno is 600 hp at 5500 and 625t at the same. I guess we will see in the spring. What is your setup?

I am a little confused, you say the husler is faster but you have only ran yours up to 4700 rpm? The motors will pull 5500?

Either way over the winter find out where neutral is on your drives and tabs and Mark your indicators. Typically it is 3 and as you trim drives out the number goes up. So if that is the case you are plowing at 2.5.

You may also try calling fountain to get the original performance report, it will at least tell you what they trim to. They may also be able to tell you the x dimension. They gave me mine.

When I had bravos on mine I ran a 32 labbed, my engines at that time made 550 hp. I ended up with 30 pitch p5x's. The 5 blades gave me much better midrange,cruising speeds than the b1. My prop shaft was 4" below the bottom.

600 hp you should be right about 90.

You had five blade on bravo?

Ya b1 uppers with the big xr shaft in the lower. Now I have scx-4's.

My 2000 twin step with 500efis would run 93 with labbed 32 bravo's. Props turning in.

Mine turns in with 34 bravos. ...my biggest gripe is the 34's seem to be so fast around the docks (at idle speed). The boat moves quite a bit of distance / pretty quickly.

But don't worry about maneuvering around the docks - if you pay attention, you will learn what works and what doesn't.

Stock 500's? GPS?
That seems fast for a 500 boat.

Not if he had it dialed in. He could get that # with 32's and still have 12% prop slip.

I'd suggest trimming the drive out more once you've on plane and raising rpms. 2.5 is a drive in condition, 3 is neutral.

Yes, gps and radar at the loto shootout. I spent a ton of time on setup on that boat. Lots of fun though.

So I just went down to the shop where I tinker all winter on my boats. The guy who owns the place only takes time off to go to proformance schools " just to tell them there doing it wrong". He work 7 days a week 365 days a year till midnight every night. he has 35+ years making shi t go faster. Certified in almost everything. Builds boats mold up. Nick named the guru. So I asked him a learned engineer what happens if you spin in or out. .... Final answer ( like I thought being a hydronic engineer myself) causes stern lift not bow. So the interesting point is that the hustler turns out causing bow. Perhaps this is how the lesser the wetted surface. I have not compared the distances of the steps to the stern. Being its a ventilated hull I think turning in could be the reason for spin-outs on some of the twin step boats. Not to mention that the lifting strakes on a fountain are rounded a bit for speed but not stability. The hustler has very sharp edges causing great stability . So if I'm wrong with the in or out science please show me the detailed proof because I'm still just listening to someone TELL me something. I want science until I can try it for myself

Without owning one I know the phrase is "spin in to win" everything I've read fountains run a few mph faster spinning in.

[QUOTE=Drew555;4386762]So I just went down to the shop where I tinker all winter on my boats. The guy who owns the place only takes time off to go to proformance schools " just to tell them there doing it wrong". He work 7 days a week 365 days a year till midnight every night. he has 35+ years making shi t go faster. Certified in almost everything. Builds boats mold up. Nick named the guru. So I asked him a learned engineer what happens if you spin in or out. .... Final answer ( like I thought being a hydronic engineer myself) causes stern lift not bow. So the interesting point is that the hustler turns out causing bow. Perhaps this is how the lesser the wetted surface. I have not compared the distances of the steps to the stern. Being its a ventilated hull I think turning in could be the reason for spin

See Bret and Bob's answers

http://www.offshoreonly.com/forums/o...questions.html

http://www.offshoreonly.com/forums/p...s-outward.html

The easiest way to understand this is to look at what's going on with the prop blades in the area between the outside of the gear cases and the chines...the low pressure side of the blade is down, drawing the transom down when rotating in ( stern leverage,)...outside rotation, the low pressure side is up, creating stern lift

Thanks jaay they almost had me thinking I was wrong lol...

It's hard to to beat that. I am looking at the prop from the force side of it instead of the negative side. ( the lift side) like a airplane wing. I would love to see a drawing if this as a example. That's only because I'm retarded! And want to learn

You running in fresh water or salt? Are your speeds GPS? just picked up a 98 35 lightning, 596hp@5800, stellings extension box's all the up (which is a 2" raise from what i have gathered), -2 imco's, and props are 1.75" below bottom. 30p bravo's 88.5@5700. 50mph@3500. This is in fresh water. From what I have been told spinning in does give bow lift.

The Hustler may not have a "pad" bottom, but it has the most aggressive lifting strakes on the planet. Its relatively dry and and very fast hull, and hydrodynamically speaking it runs like a very aggressive pad. Also the construction of the hustler is honeycomb, advanced vacuum formed composites. I don't care what the title says, tow a 388 and you will see how light it is.

The lifting strakes on a 388 become an issue when the boat nears triple digits. They get loose and dance, you fountain is designed to handle those speeds just the way that it is. Pick your poison. The 388 set the world on fire when it was released and could break 80 mph with 500s, its fast to a certain point. Most breaking 100 remove the strakes to make the 388 more stable.

I see many have questioned what hull you have, but I don't see an answer. What year 35 are we talking? There is a big difference from single, twin, small step twin and big step twin boats. Also the removal of wood in the later models made for a lighter ride. We are simply guessing without info.

Another note is a 525efi is not 525hp for the way that most dyno "home made" engines. It will spin a crankshaft dyno quite close to 600hp in dyno trim. The "525" is more a prop shaft number with boat accessories and wet exhaust. What are the specs of your "600s"?

That's an awesome number for that boat - although it appears others above disagree with me.
In practical use, I've not seen or heard of that speed with that era hull and engine in stock trim. Congrats on your work!!

He has the same hull as you. You have 575"s correct? You should be easily over 100 with that set up. Nice boat.