Well they are rated at 300lb-ft. I am putting almost 500 into mine and it has lasted through a lot of WOT and some strong shifts. Anything over 300 is on borrowed time though.
Shaun is right. I might add that it depends upon the driveline - if you run slicks and a clutch that will take more abuse than the trans can take, the trans is the weak link. If tires can break loose, that saves the trans; if the clutch slips when gobs of power go through it, that helps save the trans.
I think its all in how you drive it. I DO know that powershifting the T5 at any power level, even stock, is asking for a new TKO.
Ford put commands into the computer to actually pull timing (IE Power) during shifts to prevent shocking the tranny. This is why your cay will fall flat on its face when grabbing a gear the stomping on it. Powershifting bypasses this effect and WILL break your T5.
I think its all in how you drive it. I DO know that powershifting the T5 at any power level, even stock, is asking for a new TKO.
Ford put commands into the computer to actually pull timing (IE Power) during shifts to prevent shocking the tranny. This is why your cay will fall flat on its face when grabbing a gear the stomping on it. Powershifting bypasses this effect and WILL break your T5.
Anytime you beat on anything you take a chance that you're going to break it. The worst thing you can do is try and powershift and miss the gear, then jam it in. The synchros won't be able to match speed and you'll eventually wipe out bearings and the shift sliders. I've been powershifting mine, basically everytime I drive it, for over two years. Like was posted above, street tires on asphalt spin pretty easy so you're not eating up the abuse in the tranny so much. Just remember that borrowing time is only fun until you have to pay the car back (think more $$), but it's sure been fun so far!!!
Dont power-shift and you will be alright. My stock trans went 200 miles after a King cobra clutch was installed with power shifting. On a bone stock car with ntto street tires.
I've got a V-6 T-5 behind my 418 (500+FWTQ), and it's holding up pretty good. I'm using a Spec stage II clutch that is starting to slip a little, and I don't power shift. I also have trouble getting traction . I can tell that it won't last long if I abuse it tho.