Quote Originally Posted by RobertISaar View Post
the answer to why is one that requires you to be familiar with the way GM calculated a BPW from the BPC based masks.

the short answer is that moving the BPC is one direction will cause the table values to spread out more than reality while moving it in the other direction will cause them to group closer together. let's say with a stock VE table and stock BPC value that you see 20% VE in the weakest part of the table and 80% at peak torque. based on what you've stated, moving the BPC upwards will cause the values to spread apart(now something like 15% and 85%). a small decrease should change them to 25% and 75%.

again, that's the short (and simple) answer, but it's accurate.
Robert, I've never fully understood the BPC vs. VE workings. Thank you, your explanation helps!

dave w