Anyone running a tranny on their jets?

[copperrat20]

I was thinking about putting a 2 speed trans. on my jet. I have the room, I just haven't seen anyone else running one. Pictures?

[Hallett19]

from what I understand, that is impossible. reason being, the impeller is only effeicient up to about 7k rpms, and unless you had like a AAAA cut impeller, hmmmm, even then, who knows. I dont think its worth it. If it was worth doing, someone would have done it.

[BrendellaJet]

I think this will work if you want to underdrive your impeller, but not if you try to overdrive it... And there are a few people that are turning their impellers well past 7700 rpm efficiently...
Problem is, if your motor can only turn your impeller 5k rpm, putting a tranny in between them may result in less power applied to the impeller since the motor will be operating at lower RPMs and may not make enough power to turn the impeller the same RPM as before.
I think if you designed a motor/tranny and jet together, you may find some benefits, such as lower operating rpms... Lots of money and work though.

[Hallett19]

that and parasitic loss of power through the tranny. we jets need all the power we can

[copperrat20]

Well I saw this guy with a leinco 2 speed all polished up and for a good price I might add. Well I was thinking that the impeller is going to turn the same speed and then some. The tranny just brings the rpm's down on the motor and I'm sure that in 2nd gear I could wind it back up. I was just mainly wondering if an impeller would take that kind of power. I mean in theory if your motor turns 5000 in 1st and 5000 in 2nd, then when tached out in 2nd you would really be turning 10,000rpm. :idea:

[flat broke]

That's like saying that you have a 300hp small block that revs to 7k in 5th at 1:1 with 3.08s in back and then when you shift into a 1:2 overdrive(a little tall dont ya think) is still gonna pull the same 7k.... NO WAY IN HELL
If your mill can't pull the RPM without the tranny, it certainly aint gonna do it with a higher gear(larger impeller) out back.
Build the motor to spin the RPM that your impeller or desired impeller works best at. If you can't afford to do it that way, then cut the impeller down and live with the consequences of not having enough HP.
The only bandaid relating to gearboxes is when you have a mill that pulls big #s at High RPMs, and the HP gained by getting to those RPM is greater than the paracitic losses associated with puting a gear box in front of the pump. Once your in that situation then you would UNDERDRIVE the setup to keep the Rs up on the mill and keep you in your powerband. Of course if you can afford to build a nice prostock mill that puts out those kind of numbers, you could probably also afford just to have your motor setup to build its peak HP at a lower more useable RPM.
Chris

[SANGER-RICH]

Well I saw this guy with a leinco 2 speed all polished up and for a good price I might add. Well I was thinking that the impeller is going to turn the same speed and then some. The tranny just brings the rpm's down on the motor and I'm sure that in 2nd gear I could wind it back up. I was just mainly wondering if an impeller would take that kind of power. I mean in theory if your motor turns 5000 in 1st and 5000 in 2nd, then when tached out in 2nd you would really be turning 10,000rpm. :idea:
:cool:
How much for the Lenco and where can I find it?? PM me