You're right Jim, these aren't SOHC Neon numbers. No Sean, I'm not changing classes next year but who knows about 2014.
The "Before" is a theoretical car, but there are at least three cars with a similar weight/power ratio who can run 1:17.0 at Waterford. Granted each is tops in their class.
I was guessing a 0.5 second reduction on the weight decrease and a 1.5 second reduction on the power increase to get down to a 1:15.0 at Waterford. I thought this was too optimistic but based on Alex's weight/power ratio with a 1:16.0 lap time, I think a 1:15.0 is acheivable with the "After" spec's I'm assuming.
I know there is a lot more to this than the weight/power ratio, but it's something to start with.
Spec Neon #9