Looking to get an MP-8 and was wondering how much smoke/power/throttle response?

 

The MP8 adds 100hp/200tq. These have been very popular with the 6.7L and CR Cummins.

 

I know that the Smarty and pressure box stack was popular when the Smarty didn't do pressure but now that it does it's not so popular. The nice thing about the pressure tunes is the pressure comes on at lower RPM's which is where it really helps to get turbos spooled along with a lot of acceleration increase but it doesn't drive your max pressure past more than about 25k PSI or much over stock. Most pressure boxes will allow you to increase the rail pressure too much which will cause premature wear on your fuel system and can etch the rail pressure relief valve which is a $350 part. You may want to ask the guys at Smarty about the pressure tunes first. JMO.

Having said all of that I have been running an Edge EZ pressure box since driven off the showroom floor. I've had it off to send it in for repair and I hated every minute without it. It helps so much in spooling my turbo off the bottom that I couldn't imagine life without increased pressure but I don't have a Smarty either...............yet.