i have a 92 rs tbi, i know that stock it has 170hp and 255 torque, but i have added an open element, flowmasters and the engine was bored out 15mm i believe, so how much hp and torque does that put me up to
thanks

 

Complete exhuast?

 

no, its just the muffler thats a flowmaster, the rest is stock , 2.5'' y-pipe

 

your not gonna get the full effect with a stock exhaust and a good muffler you need to start with a good catback which wakes an engine up pretty nice, the muffler is not going to provide alot of power untill you get good flow to it and out of it, the open elements do provide a pretty good step. throttle body spacers ive fell in love with them, my 2003 s10 vortech v6 falls on its face when its taken off, when the poweraide spacer on it, itll light the tires up pretty nicely. which i have the series 10 one chamber flowmaster on it and its loud but thats about it untill i open the exhaust up a little and let it breath.

 

I have a question i have headers 2.5 inch all the way back with no muffler and the pipes T's then goes dual pipes am i losing alot of power because it seems like it

 

bored 15mm ???? thats more than 9/16" , i think you might mean .015" . .015" is enough to just clean the bore up . considering everything else is stock i would say zero increase in hp/torque . open element will help it breath a little better , flowmaster sound a little better . sorry . good luck .

 

the gains will be very mild, pretty much unnoticeable as stated already. the gains might at best compensate for a simple tune-up of the ignition components.. virtually nothing, you maybe picked up some throttle response. i'd say get some nice full exhaust at least!