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ryan9154
12-21-2011, 07:27 PM
Does anyone know the ratio of the 46 700 nxt boat that they tested for powerboat mag changing over wondering if i want to go 1.5 or 1.36

Coolerman
12-22-2011, 03:07 AM
The 700 boat had 1.5 gears

torrent
12-22-2011, 10:25 AM
Do you know what props they were spinning?

Ratickle
12-22-2011, 11:36 AM
When was that test? I thought I had every one ever done on a BT in my folder.....


Now you're gonna make me dig.....

Coolerman
12-22-2011, 04:06 PM
The 700 460 EC boat had merc cnc cleavers.... not sure on what size. Low 17" diameter I think, but that boat had the updated hull with more stern lift, so an earlier model BT might want a little more diameter and possibly raise the drive a bit. The 700 boat also ran 89mph on the limiters. Still had room left to dial it in more with props and x.

The 850 460 EC boat (also had a 1.5 gearset) ran 95mph on the limiter with more room to dial in as well with x and props. It had merc cnc props with low 17's on the diamter, but this boat also had the updated hull with more stern lift.

Regarding the merc CNC props, we bought a set a returned them before even running them. It looked a monkey had machined them, and they were damaged to boot. The merc Pro-Finish CNC props are supposedly a big step up and are comparable to the herings.

We currently run hering props and we are very happy with them. Just ordered some prop covers from Jeff Johnston today. If any of the BT guys need props (bravo or cleaver/ssm), give Jeff @ Hering a call. Let him know I sent ya.

Also, for anyone with a 460 and an SSM setup, the 17X.." 6 blades work really well on our boat. I would recommend them on a 460.

ryan9154
12-22-2011, 05:22 PM
Does anyone know what the prop x at neutral was on the 700 and the 850 boats

Coolerman
12-22-2011, 08:26 PM
Ryan, not sure where the prop x was on those boats, but I wouldn't put them any lower than even with the bottom of the boat. Our boat has them 2.5" above the bottom of the boat, but it's a little different with the staggered. What drives are you going with?

torrent
12-22-2011, 09:41 PM
Ryan, not sure where the prop x was on those boats, but I wouldn't put them any lower than even with the bottom of the boat. Our boat has them 2.5" above the bottom of the boat, but it's a little different with the staggered. What drives are you going with?

How did you come to the conclusion to place the prop X at 2.5"? With different spacers and trial and error?

offshoreexcursion
12-23-2011, 12:38 AM
I keep telling Ryan to go with the Arneson Conversion but he likes the IMCO SCX4

I keep telling Jason, torrent, to stagger his boat, but he wont listen either!

I need some Black Thunder lovers to back me up here!

Coolerman
12-23-2011, 02:32 AM
Most fast vee's have the x set anywhere from 1.5" at the lowest to 3.5" max above the bottom of the boat (depending on what type of water they are running in), but usually in the 2"-3" range. Our boat was originally rigged with them 2.5" above, we've had them as low as 1.5" above depending on props. The boat is the best now with the 6 blades and 2.5" x-dim.

Coolerman
12-23-2011, 02:33 AM
I keep telling Ryan to go with the Arneson Conversion but he likes the IMCO SCX4

I keep telling Jason, torrent, to stagger his boat, but he wont listen either!

I need some Black Thunder lovers to back me up here!

If you can do the staggered setup (don't mind the re-rig and glass work), it's the way to go. The only down side is the boat is less maneuverable around the docks.

Also, there may not be room to do a staggered in 43 straight bottom, as most 43 stepped hulls had a built in extension box that gave you 1 foot more room in the engine bay. Not having tranmissions might make it workable. It also depends on your header/exhaust setup. Could be tricky on torrents boat..........

torrent
12-23-2011, 10:55 AM
I keep telling Ryan to go with the Arneson Conversion but he likes the IMCO SCX4

I keep telling Jason, torrent, to stagger his boat, but he wont listen either!

I need some Black Thunder lovers to back me up here!

I thought real hard about staggering my current setup when I was putting it together. For the first go round I am glad I didn't. I am thinking when I purchase new drives I will then go staggered. It will be alot easier if I start the project in the winter this time as well.

I will be able to go staggered if I stay away from any drive that needs a trans. This makes drive selection limited.

ryan9154
12-23-2011, 09:20 PM
Ryan, not sure where the prop x was on those boats, but I wouldn't put them any lower than even with the bottom of the boat. Our boat has them 2.5" above the bottom of the boat, but it's a little different with the staggered. What drives are you going with?I'm going with the imcoscx-4 it will put my x about 1.5" below we run in the great lakes which is rough more than calm with the lower drive should get more bow lift and with herings magic with 17"x18 rake should be able to get stern lift if i have to go higher i can add a -3 box but i think with props we can get perfect

ryan9154
12-23-2011, 09:29 PM
I think jason (torrent) has pics or maybe a vid of my boat running see if he can post it runs very flat the way i had the props set up they are 4 blade 15.5" with heavy heavy cupping and 29 pitch

torrent
12-24-2011, 12:38 AM
I think jason (torrent) has pics or maybe a vid of my boat running see if he can post it runs very flat the way i had the props set up they are 4 blade 15.5" with heavy heavy cupping and 29 pitch

7244372444

endeavor1
12-25-2011, 08:33 AM
7244372444

That really looks no diffetent than my 02 46. It ran real flat and nose down compared to my 43's. The faster I went, the more the nose dropped

torrent
12-25-2011, 11:20 AM
That really looks no diffetent than my 02 46. It ran real flat and nose down compared to my 43's. The faster I went, the more the nose dropped

Ryans boat is a 02 46. Thats probably why they look similiar.

Ratickle
12-26-2011, 09:18 AM
That really looks no diffetent than my 02 46. It ran real flat and nose down compared to my 43's. The faster I went, the more the nose dropped


Ryans boat is a 02 46. Thats probably why they look similiar.

Could be.......

offshoreexcursion
12-27-2011, 01:49 AM
Ryan wants to run 1.5" below and the worlds fastest black thunder recommends 2.5" above? Sounds like those boxes will be needed or you could just go with arnesons which come with a box and can be adjusted to any height you want!

offshoreexcursion
12-27-2011, 01:51 AM
The answer of prop height on the 08 700 boat would help. Would it be posted in the powerboat or hotboat test?

Coolerman
12-27-2011, 02:24 AM
For Ryan, I would start at even with the bottom of the bottom because the drives are further apart.

Ratickle
12-27-2011, 09:07 AM
Are you redoing the transom? Or just using the current setup with shorties to get the height you are thinking of?

ryan9154
12-27-2011, 09:57 AM
Using the current setup The reason I'm not big on the arnesons is the tranny for one reason found out it takes about 15% more hp to spin arnesons than a bravo and I can't find out if the helm change are the same size 37 degree swivel fittings and line diameter if not all new lines no fun with a inner liner I wish bill from xpower wasn't on crack (35,000)those drives would be perfect -5 that would put me about even and a great guy to talk with hope he's at maimi boat show so we can talk

Ratickle
12-27-2011, 11:45 AM
So you are saying if you go with the minus 4 IMCO, (Which would be the minus 3 lower and minus 1 mid), you will still be 1 1/2 inches below the bottom of the boat directly in front of the drives???????


Or am I reading your earlier post wrong??????

offshoreexcursion
12-27-2011, 01:19 PM
Where did you find out that a arneson takes more hp to spin than a bravo? Does a bravo take less than a SCX4 then? So what is the SCX4 vs the Arneson? Yes X-power is sweet just overpriced. Why hate on trannies, all new fast boats have trannies.

Coolerman, What is your opinion on trannies?

Coolerman
12-27-2011, 05:11 PM
A trannie will eat up more power (not sure about that 15% # tho....), but I haven't heard of anyone putting arensons on and loosing speed unless the boat was improperly setup/dialed in. As far as drive heights go, it sucks, but you just have to try everything if you want it perfect. Staggered boats will set them higher than side by side boats.

Ratickle
12-28-2011, 10:08 AM
I'm doing some double checking, hopefully will get some very accurate input but, from everything I recall reading (and can find quickly to back it up):

A typical transmission in a V-Drive or Stern-Drive boat loses about 3% to 5% of the engine power.

The single 90 degree drive direction change in an outboard loses about 7% to 10% of the engine power.

The double 90 degree drive direction change in a stern-drive loses about 12% to 20% of the engine power. This is one of the reasons you see a 525 Merc engine dynoing at around 600HP at the crank. Merc rates them at the propshaft.

Now days, the wet drive vs the dry sump drive is reducing the parasitic loss of a stern drive. The parasitic power loss from the wet drive is almost the same as the loss from a real good transmission (allegedly).

Outboards and stern-drives have an advantage from the thrust angle vs an inboard or Arneson. But not that much advantage over the Arneson. So, the Arneson (or comparable surface drive), has the least total loss of any current system. Less changes in direction vs outboard or IO, closer to optimal thrust angle vs inboards or V-Drives. The total loss of an Arneson with a crash box has to be almost nil.

Now, pick me apart........:)

Ratickle
12-28-2011, 10:25 AM
From BAM.

With the success of dry sump drives, and almost universal use of dry sump oiling in all forms of motor sports it became obvious to us that a dry sump transmission was the next logical step. By separating the lubricating oil from rapidly moving parts, dry-sump has been proven to increase prop shaft horsepower, increase boat speed, reduce temperature and extend operating life. Testing on our digital transmission dyno confirmed an additional 36% reduction in parasitic loss (at 6500 RPM) over the %38 improvement provided by our regular CYBORG. The most extreme application to date has been the 4 engine Nor-tech cat "Warbird". Two engines on each side are coupled together through 1 CYBORG Dry Sump and a Mercury #6 drive, 1700 Horsepower per transmission!

Coolerman
12-28-2011, 11:20 AM
Nice find Paul! Here are some more #'s that merc recently published.

http://www.mercuryracing.com/blog/sterndrive-losses-less-than-you-think/

Ratickle
12-28-2011, 11:31 AM
Nice Jason......

Coolerman
12-28-2011, 01:26 PM
From BAM.

The most extreme application to date has been the 4 engine Nor-tech cat "Warbird". Two engines on each side are coupled together through 1 CYBORG Dry Sump and a Mercury #6 drive, 1700 Horsepower per transmission!

I think we'll need some better transmissions with the new motors this year...... lol

Ratickle
12-28-2011, 04:23 PM
I think we'll need some better transmissions with the new motors this year...... lol


Call Mark and tell him he's roughly 1000 hp short per side. Should be a good test for the trans capacity......

Coolerman
12-28-2011, 06:34 PM
Call Mark and tell him he's roughly 1000 hp short per side. Should be a good test for the trans capacity......

Marc has the 72-LPH. Supposedly good for 2500ft lbs..... I haven't seen anyone using them yet or heard of any feedback whatsoever.

Rik
01-17-2012, 02:38 AM
Using the current setup The reason I'm not big on the arnesons is the tranny for one reason found out it takes about 15% more hp to spin arnesons than a bravo and I can't find out if the helm change are the same size 37 degree swivel fittings and line diameter if not all new lines no fun with a inner liner I wish bill from xpower wasn't on crack (35,000)those drives would be perfect -5 that would put me about even and a great guy to talk with hope he's at maimi boat show so we can talk

I do not know where you got your figures but they are not in the ball park. The BAM tranny consumes about 9 hp and the Arneson consumes about 1. Not bad at all. As for the helm unit, all helms are physically the same (in this genre of steering systems) and use a standard dash 6 hose so there would be no need to re plumb the boat.

Ratickle
01-17-2012, 05:38 PM
Hey Rik,

How did you get the numbers on the Arneson?

Rik
01-19-2012, 03:35 AM
I called and asked BAM what their dyno says the transmission requires and I know the rolling torque the Arneson requires.

Ratickle
01-19-2012, 08:22 AM
I called and asked BAM what their dyno says the transmission requires and I know the rolling torque the Arneson requires.


Thanks. Their machine is sweet. I'm not sure anyone else measures the losses like they do.