well, you made the wrong decision since the downpipe is the most restrictive part of the car. now the most restrictive part is your motor. i would say switch it for a 3", but you'd be pissing away money at this point. your next step is what i listed there.
the catback (stock) is good for ~300whp which you are very far from.
Yeah i hear ya. Yeah i knew that, ill never make 300whp, this is just the dd. Just want to see some 14.5s out of it.