I thought I would post my thoughts on the stock/reman motor with increased boost levels. From looking at my old dyno pull vs new, and some others I have found, it seems that at stock levels the power curve is pretty flat and the more you up the boost it seems to pick the mid range up more than high rpms. The low rpms do come up but not alot due to turbo lag and what not. So it seems to basically go from a flatish curve to a more of a mountain/hump. ex. 3000rpms it may gain 30 rwtq, 5000-5500 it may gain 80rwtq, and 7000+ it may gain 40-50rwtq.

I'm guessing this has to do with port size and airflow. Once you get to the upper rpms it seems that the stock ports seem to become a good bit less efficient and you can't get the air in and out like the motor would like. Comparing stock vs. street port dyno sheets the street ports seem to keep torque up in the upper rpms while the stock drops off a good bit. Any thoughts are appreciated.

 

What you just explained is the whole concept of porting the motor. Just enables the motor to flow more, especially at the top end. You can sometimes expect slightly less hp down low than stock ports also on a streetport.

 

Yeah I know, it is just annoying to look at street ported motors that make less peak tq. but alot more hp due to the drop off not being very noticable. Hopefully within a year I'll have a ported motor.