Again, that just doesn't fit my data.
I typically see 225~230whp / 300~305wtq from cars I tune stage1 and 230~235whp / 325~330wtq from stage 2.
I don't see any great or even repeatable differences from cars with catbacks over these numbers. I've had cars with complete stock exhausts do better than those with catbacks. Last week I had a '12 with a full TBE which needed 10% more WGDC to hit the same boost targets as other stg2 cars did with a stock CBE.
Terrible things like this don't happen where I come from. Other terrible things happen instead.
Obligatory 'build thread