Ok, lemme explain my actions. Wanted sound, couldn't afford BMW PE, opted for Y-pipe muffler delete. Couldn't notice at first, gradually got louder, still way quieter than all the youtube vids. I would imagine the PE being of equal or more volume. Cold starts and heavy accelerations were the only time this setup was slightly loud. Still had that annoying vacuum cleaner sound after letting off at high RPMs. Little to no drone, only under heavy throttle and low RPMs. Anyways, started looking at headers or secondary cat deletes. won't pass the strict smog here in CA, so I just had a shop delete my resonator and replace with Y pipe. "If it was too loud, I could always add a vibrant/AR30/glasspack res". Instantly noticed the difference. It is like my car was half awake this entire time and now just chugged a redbull, ready to burp and yell. I would say this is now twice as loud. It backfires under decel, but not overly obnoxious. I can control the backfire amount with the gas. LOTS of burble. Free revs are MUCH more angry. Cold starts are also noticeably louder. I do feel self conscious sometimes as more than 30+% throttle at any speed is noticeable by anyone around you. However, WOT is absolutely orgasmic. Not raspy really, but LOUD and it feels faster top end. I may add a smaller resonator if need be, but right now I like the volume and the tone. It does drone quite a bit more if you hold it at the 2500ish RPM range with heavy throttle input. No more vacuum cleaner sound, instead a healthy, guttural growl at high RPM throttle let-off. Overall, very satisfied, especially for price (~$150, I gave my guy a tip
). If someone is in CA, looking for a decent sound and tone increase while being smog-legal, I would delete the resonator OR the muffer and replacing with a Y pipe. For the braver, go both
P.S. Videos are coming soon, including: fly-by, cold start, warm start, free revs, decels and interior/exterior accels
EDIT (7/27/2018): Has gotten louder, still love it. The backfires are more common now and if you go over 4k RPMs in any gear you are guaranteed to get a few pops here and there. 1-3 gears are the best for all the burbles/pops. Video is almost done, just need to film some fly-bys.
UPDATE (9/13/2018): Decided to delete my sec. cats. She is obnoxious... and I love it. backfires to hell and back in nearly every gear at the right RPM. Maybe twice as loud as before. Stinks on cold start and spits spray of emissions on to the ground. Cold starts are damn near deafening, but surprisingly my neighbors don't mind as they all have loud ass cars too
. After a few days, car learned its new parameters and feels freer in top end, revving faster than before. definite power boost, not just a placebo. Only con to this was that now I had a reason to fail smog (but should still pass as my primaries are still in) and that it cost me a lot (~$100) to remove because NO shop in my area wanted to remove them because of legal issues. Other than that, I am a very happy guy. Perfect tone for me. Not raspy until high rpm, more guttural growl and a free rev decel burble i LOVE. she sets off car alarms, pops like a machine gun and wails like a banshee! vacuum cleaner noise has been demolished. this is how the rural bavarians would have wanted their bimmer to sound. will post videos soon. Current setup: full straight pipe from primary header cats.