Had the Milltek OPF-back exhaust fitted today. It went on with minimal fuss, just a little tweak to the backbox mounts as the resonator is larger than OE and needed a bit of spacing to give good clearance of the heatshield. Here's a few pics:
OE exhaust removed:
Comparison of Milltek tip v's OE:
All buttoned up:
Had a 30 mile drive home from fitting. Here are a few thoughts:
- Cold start is louder than OE but not obnoxious. Quieter than my M3 was on its stock exhaust!
- Idle is pretty quiet, really not much louder at all
- In car it's definitely louder, accelerating in 2nd generates a fair amount more noise. It definitely changes the exhaust note, not just amplifies it. I like it but it's not sonorous - it's still a 4-pot!
- I've not noticed any intrusive drone at steady cruising but the drive was all NSL A and B roads. I've got a longer motorway journey tomorrow so that will be a better test
- Exhausts tend to 'bed in' over time. Not sure if this is still true with the cleaner emissions due to the OPF but it'll be interesting to see if anything changes in the sound over the next 500-1000 miles
- Looks: I went for the polished tips to keep a more OE look. I hadn't fully appreciated how huge they are but they fill the opening in the diffusor nicely. I think they give the back end a bit more of a purposeful look so I'm pleased