I just got back from running my tunnel with 18 gp3700's a 10XL on a modded K&B lower unit and a Barra 125 ESC. I plugged in the whatts up meter to see the amps and it was 88 AMPS with a X440 prop...then i tried a 1440 back cut (my sport 21 tunnle prop) and holy **** did it fly then!!
There is a current thread going on about FE tunnels, its about 8 pages long and can be found HERE , Although you will have to weed through a page or two of bitching and moaning, its got some good stuff.
I am using a REK/Irwin composite lower unit with a Neu 1512 brushless on top.
here is an older picture from when I was setting it up.
I just got back from running my tunnel with 18 gp3700's a 10XL on a modded K&B lower unit and a Barra 125 ESC. I plugged in the whatts up meter to see the amps and it was 88 AMPS with a X440 prop...then i tried a 1440 back cut (my sport 21 tunnle prop) and holy **** did it fly then!!
the boat looks good - btw the new software for the esc is definitely a winner I dont know how they did it but it is transformed and I cant fool the esc by stabbing the throttle and the lags when puching it are non-existent
The current reader is a good tool - what you will find is sometimes the biggest peaks are as the boat gets on plane the first time - then after that they are say 20% lower (thats a guess but its lower).
I have a 9XL dyno test too. The logger readings help to select props to put the amp draw at max efficiency for the voltage. Also if you know your amp reading you can tell what rpm your motor is running at as the two coincide in the top half of the rpm range. This means you can work out a figure for your hull efficiency which will let you work out speeds more accurately and asses how props are going. It also lets you check pack voltage when it matters most
I took the boat out on Sunday i took the tunnel out again, but the speedy was knackered because i shorted out the Rx red wire in another port on the Rx and made a chip on the power board is burnt :lol:
But that was my fault of course.
Anyway I got a reading of 108amps for the 1440, but the controller didnt seem to be getting full power probably due to it being stuffed so i think that the AMPS might drop with the controller working properly.
So i think i might drop back to an 9XL and 16 cells so i can pull the 21 tunnel props better...
Just what you need Ronald, another FAST boat. You already have one boat over here that is so fast that you will need to re adjust your hand-eye coordination to drive it!
where can i pick up that gold mount for the transom. I got the lower unit and everything else i just need the mount. also can some one post some links to some boat kits and hulls, mines going to fast as it is already (brushless on an abs academy f1 :blink: )
Just what you need Ronald, another FAST boat. You already have one boat over here that is so fast that you will need to re adjust your hand-eye coordination to drive it!
