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splashandburn
05-16-2016, 07:42 PM
What are you guys running for drive height on your BT's? Anyone know the approximate depth they are below the running surface directly in front of the drives? Any help would be greatly appreciated.

Ratickle
05-16-2016, 07:59 PM
Are you still running at this depth?


Here's a photo. I did measure it again from the bottom of the boat directly in front of each drive to the centerline of the prop and its actually closer to 6" below that point.

75968

splashandburn
05-16-2016, 08:10 PM
Yes. I never got the boat dialed in last year - ended up blowing a motor @ less than 30 hours. Both motors reworked (again) and pushing even more lower now. I'm getting extremely high slip numbers running a 32P Bravo I prop. Just received new drive couplings to put the drives back to stock depth which looks to be close to 4" below the running surface.

Ratickle
05-16-2016, 08:17 PM
Don't know why the photo didn't come across in the quote. Here it is:

http://i730.photobucket.com/albums/ww310/ptrose/splash%20and%20burn%20drive%20height.jpg (http://s730.photobucket.com/user/ptrose/media/splash%20and%20burn%20drive%20height.jpg.html)

splashandburn
05-16-2016, 08:32 PM
Yup that's it with the spacers installed. Removed now and IMCO SCX uppers installed.

Coolerman
05-16-2016, 08:35 PM
Ever tried 5 blades? Seen several 460's that like, not sure what 5 blades they were.

splashandburn
05-16-2016, 08:44 PM
I haven't. I do think the boat needs bow lift though I can almost feel it plowing at speed. I'm wondering if the spacers were pushing the bow down?

Coolerman
05-16-2016, 08:47 PM
Spacing the drives down usually leverage the bow higher.

endeavor1
05-16-2016, 08:54 PM
My 02 46 with KE675s or as dyno proven 699s ran BMAX drives with standard XR lowers with Hydro P5X props. Boat handled good, carried the nose and was enjoyable with minimal tab. Same boat with 4 blades became an absolute turkey. Try no spacers and P5X props.

Btw, my first 43 had -2 lowers and when I put standards on it it slowed and completely changed for the worse its handling. John P with No-Comp (trip 850) 46 saw gains after we discussed -2 vs std lowers.

Short drives/more prop... Have fun

splashandburn
05-16-2016, 08:56 PM
Hmmm....not sure what I've got going on then. I was thinking that having the drives that deep was increasing my slip numbers. I'm running close to 30% slip @ WOT.

splashandburn
05-16-2016, 09:01 PM
New motors dynoed at 890 hp. Boat seems to hit a wall @ 74 mph. How is it getting on plane with -2? I seems to really blow out the 32P props WITH the spacers installed - can't imagine what it'd be like with 4" less in the water

Coolerman
05-16-2016, 09:01 PM
Are you running the props that came on the boat, or do you know the history on the props before you got them? Or has anyone worked on them?

Ratickle
05-16-2016, 09:03 PM
When I look at the tab locations on your photo I'm confused. Are they mounted within a half inch of the bottom? And is the port lower than the starboard, or is that a visual mirage?

endeavor1
05-16-2016, 09:07 PM
4 blades on my 46 blew out, my current 43 did too until b blades worked them. 5 blades on my 46 hooked up and rolled on plane no issues.

If I had 890hp and hit 74 I'd be crying. I hit that Friday night late under the community bridge @ Loto with my catastrophe of power I call engines...fWIW, when my engines were procharged they were odd to understand the power and along with finicky. 775hp per dyno.

Call me if I can be of any help to discuss my setups.

Ratickle
05-16-2016, 09:08 PM
Also, with your spacers installed, I have to believe the cavitation plate was running in the water even at WOT. They were just too low.

Typically the water starts to rise to its normal level as soon as it leaves the transom. Your cavitation plates appear to be lower than the bottom of the boat in the photo. I think they were displacing water and aerating the water to the prop also.

splashandburn
05-16-2016, 09:15 PM
Are you running the props that came on the boat, or do you know the history on the props before you got them? Or has anyone worked on them?

I have a set of stock Bravo I 28P props that I know are untouched and a set of Bravo I 32's that were Mercy labbed.

splashandburn
05-16-2016, 09:20 PM
When I look at the tab locations on your photo I'm confused. Are they mounted within a half inch of the bottom? And is the port lower than the starboard, or is that a visual mirage?

Yes both are close to 1/2" down and at the same level. Must just be the pictures angle. .

endeavor1
05-16-2016, 09:26 PM
My 43 with PC'd motors ran 32 b1 props as info.

splashandburn
05-16-2016, 09:35 PM
My 43 with PC'd motors ran 32 b1 props as info.

The 32's seem to be the right size as I spun them to 5100 rpm but it seemed to be dragging. I could actually feel (and see) the speed increase if I turned the boat slightly. The water was dead flat though.

endeavor1
05-16-2016, 09:36 PM
Saxman... Why are these boats turkeys to dial in?:icon_bs::cuss::seeya:

endeavor1
05-16-2016, 09:37 PM
The 32's seem to be the right size as I spun them to 5100 rpm but it seemed to be dragging. I could actually feel (and see) the speed increase if I turned the boat slightly. The water was dead flat though.

Wow... That's interesting. Any chance you could bolt some 5 blades on to try? I don't have any otherwise I'd loan you a set

There's a set for sale p5x 32 s on oh so slow. John P knows the owner of them if he can help

splashandburn
05-16-2016, 09:41 PM
I'd love to try a set of P5X. Had them on my Sonic and loved them - should've kept them when I sold the boat

Nevr2nd
05-16-2016, 09:43 PM
I'm not gonna be much help on this...simply because I run SSM 5's and Five blades. (17 1/2 X 30) On my BT.
However I will harass Saxy and Enis the Penis( Endeavor). 😊.

endeavor1
05-16-2016, 09:44 PM
Don't ban me Rat...:biggrinjester:

http://www.offshoreonly.com/forums/swap-shop/336953-hydromotive-p5x-32-left-right.html

endeavor1
05-16-2016, 09:46 PM
I'm not gonna be much help on this...simply because I run SSM 5's and Five blades. (17 1/2 X 30) On my BT.
However I will harass Saxy and Enis the Penis( Endeavor). ��.

Keep it up and you ll have a spite baby too... Lol

Btw.. Called about my lift and got that Jewed back where it was supposed to be #winning #maga

TRUMP 16'

Coolerman
05-16-2016, 09:58 PM
I'm not gonna be much help on this...simply because I run SSM 5's and Five blades. (17 1/2 X 30) On my BT.
However I will harass Saxy and Enis the Penis( Endeavor). 😊.


Enis the penis and his dog Tacoooooo? Make sure you get doggy bag fo carry out.

https://www.youtube.com/watch?v=3G9MnGqG9vI

endeavor1
05-16-2016, 10:00 PM
:sifone::smash:Thread derailing in ...3....2...1...

splashandburn
05-16-2016, 10:02 PM
So does drive height of approximately 4" below running surface seem about right for factory?

Coolerman
05-16-2016, 10:04 PM
That's too low for any boat imo......

splashandburn
05-16-2016, 10:12 PM
I'm guessing there's nothing special about how BT set this boat up though right?

endeavor1
05-16-2016, 10:15 PM
Doubtful. 03 was a design change year iirc and your boat was originally a 500efi that had PCs added later in life. Not sure if any BT was ever cut the same. Lol

FWIW, my current 43 is a bit deep on the X.

splashandburn
05-16-2016, 10:18 PM
How deep would you guess?

endeavor1
05-16-2016, 10:22 PM
I'll measure tomorrow. That way I'm spot on but iirc 2 1/2

splashandburn
05-16-2016, 10:24 PM
Thanks that'll at least give me somewhere to start from. Just curious - why did you remove your PC's?

endeavor1
05-16-2016, 10:32 PM
Thanks that'll at least give me somewhere to start from. Just curious - why did you remove your PC's?

Headaches. My boats plumbing was so F'ed up when I bought it you wouldn't believe it if I told you. That, popping drives and widely varied EGTs didn't give me any warm fuzzys. Really would like to go back with blowers, just gotta spend the $$$ and that's hard for me to do. Lol

splashandburn
05-16-2016, 10:47 PM
I completely understand. My PC's actually caused my engine failure. $20 flame arrestor broke apart and was sucked thru the motor - destroyed everything. Needless to say they're no longer there

Ratickle
05-16-2016, 11:21 PM
I also believe your tabs are too low. At only a half inch above the bottom, they will be active at almost any speed unless they are trimmed up past horizontal. Take a look at this recent tab thread: http://seriousoffshore.com/forums/showthread.php?t=24849

If you can, put a go-pro or other video camera on your boat to watch the transom while underway. If you can see what's going on back there it will help with corrections. However, I believe that removing the spacers will make a huge difference.

And, before you test, make sure you have your indicators on both the tabs and drives set properly so you know where zero is at to start from.

You'll want to know where the tabs stop being active and where the drives give you the best speed.

Just set the drives at neutral once you get on plane and raise the tabs all the way up. Go to your top speed, then tap the drives up a little at a time until they blow out. Then down a tap or two should give you the best overall top speed. You need to know where blowout occurs, and where neutral is. After that, everything in between is your working range and you will want to note your speeds at different rpm's.

That boat should not need any tab at speed unless there is a crosswind, really rough, or a whole lot of passengers and fuel.

http://seriousoffshore.com/forums/showthread.php?t=24849

splashandburn
05-17-2016, 03:34 PM
Are you guys spending props in or out?

splashandburn
05-17-2016, 09:01 PM
Anyone?

Ratickle
05-17-2016, 11:23 PM
Out for all around control and handling. In for top speed.

I always say start with out. If the boat handles and does everything perfectly, you can always try in for a loss in handling but more top speed.

splashandburn
05-18-2016, 06:43 AM
Bblades is telling me that they always recommend spinning in on BT's for more bow lift. Saying that too much stern lift is an issue with these boats.

Ratickle
05-18-2016, 08:44 AM
Well, Brett certainly knows a lot.

The good thing is you have Bravo's. Changing to test takes about 10 minutes......

splashandburn
05-18-2016, 08:19 PM
I'll measure tomorrow. That way I'm spot on but iirc 2 1/2

Were you able to get a measurement of your drive depth? Please let me know. Thanks

Ratickle
05-19-2016, 07:40 PM
Did Chris answer you?

endeavor1
05-19-2016, 10:05 PM
Sorry... Busy as hell. Mine are 3 under. Interesting that's what BBlades told you bc I was told the exact opposite by them when they did my props last year. Lmfao...:smash:

I ll try it though

endeavor1
05-19-2016, 10:07 PM
Also... Looking for a 741 crane cam or 525 EFI takeout cam. Had a gremlin find a home in a lifter:boxing_smiley::cuss:

splashandburn
05-20-2016, 07:31 AM
Sorry... Busy as hell. Mine are 3 under. Interesting that's what BBlades told you bc I was told the exact opposite by them when they did my props last year. Lmfao...:smash:

I ll try it though

Thanks for the info.. You're running stock drives not -2 shorties right?

endeavor1
05-20-2016, 09:59 AM
Correct. Std length lowers

splashandburn
05-20-2016, 11:25 AM
Thanks that gives me somewhere to start from

Coolerman
05-21-2016, 02:31 PM
Regarding adding bow lift vs stern lift, I know the later 46's had stern lift built into them and they handled muuuuch better, however, some people argued that it slowed them down a few mph. On some of the earlier 46's like Bingham had, I believe he had 5 blades and the boat ran good as it was. I know John P's trip eng 46 ran better when he put on shorties. There area lot of BT's out there as well where the bow runs too high, more so some of the 43's....

One thing is for sure, each BT is unique and they all run just a bit different. A lot this can do with motor options and other weight distribution factors (IE: if the boat had a generator, fridge, big stereo, heavy blower motors vs stock power, etc). The last style hull from BT with 700's and NXT's was the ticket, ran 90mph and handled great.

On our boat (a completely different setup, 43 flat deck and 6's), we don't have enough bow lift spinning in at slower speeds, but it flattens out as you get going faster. Spinning out is great up to about 100 or so (rides like a caddy and handles like a go-cart with sticky tires), then it gets too much stern lift at 100+.

If it were up to me and I had a 46 with Bravo's, I'd probably try -2's with 5 blades and adjust the hull for stern/bow lift as needed. Making hull adjustments really isn't that hard to. That way you can run an off the shelf merc or hering prop so it is easily replaceable if it gets damaged, and it isn't hard to match.

splashandburn
05-22-2016, 05:46 PM
If it were up to me and I had a 46 with Bravo's, I'd probably try -2's with 5 blades and adjust the hull for stern/bow lift as needed. Making hull adjustments really isn't that hard to. That way you can run an off the shelf merc or hering prop so it is easily replaceable if it gets damaged, and it isn't hard to match.

I'd love to try a set of shorties but a pretty big investment without knowing how the boat would run with them. I think I'm going to pull the 2" drive spacers and try a set of 5 blades to start. What type of Hull adjustments can be made to adjust bow/stern lift?

Ratickle
05-23-2016, 05:32 PM
I'm curious on that too Jason.

Ratickle
05-28-2016, 12:17 AM
Come on Jason...:toetap05:

:)

Any tests yet Craig?

Coolerman
06-08-2016, 11:35 PM
You can add some turn downs or widen the strakes on the front pad of the boat to add bow lift, or do the same on the first strake in on the outside chine on the back of the boat to add stern lift.

endeavor1
07-05-2016, 12:59 AM
Turn down for what?

Ratickle
07-05-2016, 10:38 PM
Any test information yet?

endeavor1
07-15-2016, 04:36 PM
My boat seems to run better downhill :smash: