how much hp is possible in an MKIV n/a?

including all the bpu's as possible? turbos, engine mods...etc?

ps. whats the best e.t. for 1/4 mile?

Hmm, you could do 11's probably for sure.
About HP....I would say around max 450. Hp is not that all that matters in a 1/4 mile...its traction, road conditions, torque and DRIVER SKILLS!

Well the best 1/4 time i seen is 8 sec...but thats on a turbo. On a N/A....not sure.

i costs about $6000 to 8000 to put a single turbo on if the n/a isn't fast enough but you don't want a new car