drive ratio

ryan9154

New member
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
 
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.....
 
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.
 
Last edited:
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?
 
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?
 
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!
 
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.
 
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..........
 
Last edited:
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.
 
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
 
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
 
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!
 
Back
Top