Two different cars is still a huge variable.

 

Two different drivers is a bigger variable

 

We both had 60 ft and et within 2 tenths so the driver factor is irrelevant. Different cars isn't a 3 mph factor unless one is a factory freak. It's possible, but less likely IMO than the car simply responding to mods better than people think. I actually don't think I've seen a before/after dyno for a DP of a GMS1 car, let alone one on the same day. Is there one showing less than 10 hp? If so, I'll admit that it's simply down to the car although it would make me regret selling it lol.