Like the title says.

Does anybody have any experience on how much TQ\HP an NA DS can take?

A friend had the front yoke break on his NA vert and it broke the shifter turret off the tranny. It looked to me that the yoke had been nicked at some point which caused it to break. especially because a stock S4 vert does not have enough torque to break the yoke IMO.

The reason I am concerned is I recently finished an NA to turbo swap on an S4\Auto and used the driveshaft from the auto.

My combo is putting about 250hp\230tq to the wheels.
Ported 6 port keg
9.4 rotors
TII intake
S5 hybrid turbo 8psi creeps to 10psi
680cc sec. injectors
HKS FCD
RB turbo back exhaust
ebay FMIC

 

A quick search reveals that the auto driveshaft is a little too short. Whether the yoke will handle it or not, I'm not sure, but any driveline movement could cause the DS to pop out. And I don't think I'd be so concerned with the yoke, but those 20 something year-old u-joints instead. They're probably going to be your weakest link.

 

my shaft jet snapped at the u joint. last week just got her fixed.. so i guess its possible..

 

I did the same thing once. broke the yoke which in turn cracked the rear housing and broke the shifter linkage area.

 

It's a full 2" too short. It sticks out nearly halfway. Using the auto driveshaft is a horrible idea, yet I still see it get suggested here.

Get the driveshaft extended 2", or use a Mazdatrix custom shaft w/ the TII yoke and an NA flange.

 

i had the same thing happen to me on my vert

 

What I meant to say was I used the auto yoke on the NA driveshaft.

 

Wait, you didn't specify if your NA/Auto Turbo-swapped car was converted from an NA/Auto to a Turbo/Manual or Turbo/Auto.

What exactly are we dealing with here? If it's a Turbo/Manual, and you had a driveshaft shop replace the yoke of the NA driveshaft with the one from the Auto, then it'll work because it's going to be the right length.

I wouldn't worry about snapping the yoke, just make sure the U-joints are good. If they need to be replaced, search RotorWiki for the procedure on how to do it. Otherwise, unless you're putting down some CRAZY torque (lol... torque in a ROTARY... pff) then the yoke is going to be fine. Your friend's ds probably snapped because the u-joints took a poop long before, causing a cyclic stress on the yoke.