Twin Stick Transmissions and Modern Powerplants

There are plenty of folks that run them behind higher horsepower engines.

They won't last as long as new transmissions and need to be driven with care, like avoiding full throttle at lower rpms, but they can work.

 

There is an interview on big rigs videos from 3 Bar C and he runs 1000hp cats in his two trucks and that 79 KW has twin sticks.

 

We run quite a few twin sticks behind Cat 3406s. We've had good luck with them lasting but most of the drivers know how to handle them without tearing anything up.
If you're getting sticks just because you want them you'll probably be okay. But if you have somebody else drive that truck you better make sure they know what they're doing.
No shame in getting an 18 spd.

 

Like many other things with these trucks, what you do with your right foot has a big effect on the longevity of the transmission.

There’s a few guys out here still running sticks, and with bigger HP, it’s just knowing when to use all them horses….

 

Just go by the numbers. 1406A and 1241C, that one of the over-over 6+4 sets. 1400ft/lb main and 1200ft/lb auxiliary. And they sold them to us screwed to 3408’s and KT’s with 38k rears. With the a-box in the low hole I’ve wound 1810 shafts up tight enough to pull the slip yoke out and never hurt the boxes. The truck I have now has had an RTO14715 in it for 8yrs, on a C15 that puts up about 2100ft/lb. It’s all in how you drive them, truck drivers didn’t have many problems. Now you give people 2000ft/lb clutches and transmissions with 46k diffs and they still manage to smash the #### out of everything. It’s not the torque rating of the components causing that, they’re more about warranty liability than anything.

 

There's a couple members here that are running Twin box's behind some serious Hp motors..
As @Oxbow said you better know what your doing and when too & when not to shift otherwise your gonna have a pile of toasted scrap metal
There's little tricks and improvements that need to be done with higher hp motors in front of them .. but thats a whole different subject of another day
I ran a 5 & 4 behind a 3408 for years .. got along well with that combination

 

And the number one reason why the big carriers are going to autos and detuned gutless engines.

The stronger the engine, the most finesse is required from a driver.

 

Those guys never learn. Remember when they bought all those 290’s for the fuel mileage? That worked out well for them.