Originally Posted by jezeka777

Hi guys I have a GTM 1.5 SC 370z and live in Long Island. I'm currently making 481whp and 364tq with stock exhaust. I just recently changed my exhaust to Fast Intentions with 18" res and the car sounds like a beast but seems to be running a bit different. Low and mid end TQ has improved but high seems like its dying down. This was the total opposite when I was running stock. Think I need a retune????