.My STi 4 now has a Unichip and Scoobysport DP.Would I gain anything in terms of BHP/torque/throttle response by replacing the mid and backbox,considering that the mid does'nt contain a cat.If the answer is yes does anybody know which is the quietest.Also the magnex midsection with resonator,does this offer more resistance to flow than the one without. Cheers guys. Deep.

 

Sorry the title is misleading,I already knew that the mid has no cat,I was'nt thinking sraight.

 

I changed my sti mid for a straight through pipe (60ukp from Scorpion). Did make a difference But was told there wouldn't be a difference if it had been a resonated section - effectively like for like with the sti