Hi guys... just wanna to ask if any1 noe abt it.. i hv a 4g91 lancer auto tranny ya... i wanna change the exhaust.. currently i hv a kakimoto r straight flow given by my frend.. same as the pic below..



btw the inlet is 2.3" outlet 3.5" without silencer 1" with silencer.. i wanna fit tis muffler into my auto tranny car but i noe i will lose backpressure causing lack of torque.. so the question is.. can i add 1 s-flow midbox to increase backpressure & tis muffler at the end of exhaust. will it work for auto car? thx btw...