And this will be the finish. Got everything installed today on my day off. As some of you may remember, I had installed the Magnaflow 14816 Mufflers and while I loved how it sounded, the drone was a bit much. My solution consisted of ordering a Magnaflow True X pipe, Aero AR25 Resonators, and OBX generic resonators. Why? I was going full custom. I already had my secondary cats taken off and replaced with straight pipes for those who had seen my post a few months back. To solve the drone issue, I used the helmholtz formula to create helmholtz chambers to cancel out the drone frequencies. This is what the OBX universal 2.5" resonators were for. For those who don't know, the OEM x pipe is crap--there is just a small "hole" where the exhaust gasses are supposed to crossover. Compared to the new magnaflow X pipe, this one was wide open. I already knew there were gonna be some positives with the new X pipe once I compared the two. The resonators replaced the OEM ones just past the x pipe. They fit perfectly. I had my tech create new pipes from the resonators back to the mufflers. Very straight through design with very few bends. He tried to make both of them perfect, and I think he did. The helmholtz chambers were created just as they are meant to perform, I needed roughly 13 inches to cancel out the frequencies, and they are placed where they belonged. I used the AA exhaust as a reference for the location where the pipes were to come off a 90 degree angle. 3 hours later, my new exhaust was done. The result? Absolutely little to no rasp, ZERO drone, and Immediate notice of more "pick up" with the new x pipe. He polished up the welds, especially on the helmholtz chambers, and they look fantastic. Really aggressive from behind. I absolutely love it and it is the most perfect thing I have heard besides women's sexual moans. Let's not go there. Of course, I will provide pictures and stand by for a sound clip either tomorrow or Sunday. I spent about $800 overall on EVERYTHING, including labor and parts. Couldn't be happier.
2008 (07/08) E92 M3 BPM Stage II Tuned by Mike Benvo, 6MT, Turner Test Pipes, Magnaflow Custom Catback Exhaust (Magnaflow X Pipe, secondary cat delete, Aero Resonators and Helmholtz Chambers),Vorsteiner CF Lip, Hamann Style CF rear diffuser, CF Rear Decklid Spoiler, BMW Performance Kidney Grills, CF Side Grills, OEM GTS Wheels, K&N Drop-In Filter, GP Thunder 8k Angel Eyes, Painted Reflectors.