Hey all so I just recently rolled 100k in the 8. I have plans to shoot for 400-450whp, maybe 500 eventually. Is it even feasible for the motor to last long at those levels with high mileage or should I rebuild first?

 

It's feasible but no one can tell you what your motor has been subjected to in the past.

 

be good with maintenance and smart with your driving. I am at 118k miles and about 440 whp. I bought the car with 24k miles completely stock from a middle aged man who babied the car. I kept it stock (minus exhaust) till about 50k miles. From there, the power just kept climbing hp by hp and ft-lb by ft-lb.

Talking with a lot of evo owners and shops, 450 hp seems to be the general consensus as to where things start to get iffy on stock parts. I have seen them push into the 150k mile range no problem with good maintenance. There is a dude here in the Bay Area that is over 200k and he is a maintenance genius.

It also has a lot to do with the history of the car and the driver. If the car was beat to **** by the first owner during the first 50k, then I wouldnt expect much. That being said, I would aim to be in the 400-450 hp range only if you feel that when (not if) the motor goes out, you can handle the down time and the cost to get her back up and running. Also, I would say to save the rebuild for later and ride things out on the current motor.

Edit: It is torque that kills motors and drivetrain components. You can always ask your tuner to tone things down and be conservative in that area of your tune. My current setup is easily good for 500+ and it made a few mustang dyno passes around there, but I asked my tuner to ultimately keep it conservative.

 

410 ft/lbs on a dynojet is not exactly conservative from everything I've heard man (and definitely not on a mustang). Depends on where you make peak torque though, I'm guessing with your turbo is pretty late.