I'm running the resonator delete & I'd advice against it.
in the past, I had the Eisenmann SR pipe + Eisenmann race rear muffler. Then I pulled out the Eisenmann SR pipe, sold it Route 16 here, put back the stock pipe, deleted the resonator for the loudness.
Even though my car gets quite a bit louder, but I can tell I lose some backpressure & therefore horsepower.
My car isn't as responsive as a friend's stock 325i.
I'm about to buy the Eisenmann SR pipe & slap it on again.
Frozen Grey. Dry CF Roof. Vorsteiner Double Sided CF Boot Lid. OSS. BMW Performance Aero Kit. BMW Performance CF Diffuser Cover. BMW Performance CF Trim. Robson Design Steering Wheel. Advan RS. Michelin PSS. H&R Touring Cup Kit. BMW Performance Brakes. Eisenmann Race Rear Muffler. ESS Directflash