Hi guys, im new to this site, but not new to the modded car world

any ways, ive just bought me 1st Audi ever.
A6 1.8T Quattro Se 2001 Y

ive been looking at home remap for these. ive got some good prices aswell best being 225. just wanting to know if any on has remaped thier 1.8t ??
couple of questions i have are ....

what was the impact on fuel consumption??
what sort of gains did u manage to get ??
What RPM is the turbo kicking in ??
and does the turbo ever decide to clonk out and stop spooling(working) because it kicks in at low revs or any thing like that??

reason im asking is one of me mates got his passat remaped and his turbo was kicking in at 1600rpm and used to stop working evry now and again when it was in continious use.

any info would be much appriciated
thanx