[bellabimmer]

I want to share some information about my exhaust in X5M F95.

I have Racechip GTS Black and before when exhaust was stock I wasn't happy even a vacuum cleaner was more noisy than X5M EU Version due to OPF then I buyed Gpower exhaust and secondary downpipes...my car is EU Version so GPower Exhaust also removed the OPF so I was very impressed with the sound etc but then I still wanted more noise with valves open it was not that loud for V8 for me.

So what's next I buyed primary downpipes and I was full catless with GPower exhaust ( GPower exhaust has two small mufflers in the end and middle resonator with perforated holes which I saw from inside how it looks ) so then difference was big I liked the new sound...turbo spooling...sometimes even good backfire when downshifting upshifting etc.

After 1+ years or more I used to be tired from this configuration because on longer trips it makes me tired from exhaust drone...I can't drive always fast or always at high rpm in longer trips so highway speeds in 8th gear we couldn't talk well inside car due to exhaust drone...then just google searching etc I have read some topics that XPIPE increases noise and reduces drone ( I was happy with noise from GPower but I could accept more noise if I have less drone so I removed that middle resonator and did XPIPE then noise increased drastically like another 40% or whatever... cold starts crazy even with valves closed but again drone was there no difference in drone before or after and cabin noise was fine but still drone )

Then lately I removed all GPOWER Exhaust and reverted stock exhaust ( have cut both OPF and Resonator from it and considering how big the stock exhaust mufflers are and how much silent car was stock intuition played me and said put XPIPE instead of stock resonator so I did that and car is crazy loud in cold start with valves off constant turbo spool when driving slow speeds - pushing over 4k rpm with valves closed also goes crazy but if you open valves hell loud )

I have dahler tunning valve remote controller so I keep them full closed while in comfort mode but cold start is craziness and this bothers me because I can't just turn car easily in underground parking and more cabin noise inside when pushing under load when car is going slowly...

There is a guy in same city with X6M same configuration as me just stock resonator in exhaust not XPIPE like I have now and to be honest I don't like that engine noise in stock exhaust as that so this XPIPE mod creates an unique sound which is very good raspy, sportier etc my friends and everyone likes it also the EU models have OPF stock so our cars run more rich here for example they have more burbles and sometimes downshift creates bangs so with this mod with XPIPE its like you have pops and bangs enabled there is big difference in burble/bangs compared before with GPOWER exhaust but the cons is cold start.


Did my last change with xpipe and stock mufflers it fixed exhaust drone...yes that is eliminated not 100% but most all of it whats not good loud cold start sounds and cabin noise when pushing under load with high gear/low rpm.

I have a friend here in forum who runs catless downpipes he has FI Exhaust and as you know FI Exhaust has no middle resonator but xpipe instead of that and this friend has no drone and he can live with cold start and driving with valves closed.


Whats next...I don't know putting cats back primary or secondary is not an option for me but I am thinking on putting back stock resonator and maybe keeping xpipe too that way perhaps loudness will be manageable or remove totally xpipe and just put stock resonator ( I will not like much that sound since I know how it sounds in the guy with X6M and loudness and cold starts will not be big issue after with stock resonator but sound is not also that good so perhaps both xpipe and resonator together will help in loudness and type of sound )

I wish I could sell my GPOWER Exhaust first and buy FI Exhaust but it is what it is.

Sorry for my english not perfect but I wanted to share my opinion in my exhaust mods so far, so perhaps someone who wants to go catless on stock exhaust with xpipe...think twice cold start will be a big issue and turbo spool and that noise in cabin when being in slow speed high gear under load.

If someone here is catless in akrapovic or fi exhaust or any other brand please let me know how it is do you have drone how is your cold start etc.

Feel free to ask me anything if you didn't understand something from my experience on this changes.

[johnnyredgtr]

Great review, thanks for sharing. Being catless, primary and secondary, how you fix CEL light?

[bellabimmer]

Originally Posted by johnnyredgtr

Great review, thanks for sharing. Being catless, primary and secondary, how you fix CEL light?

I have no CEL light because I have installed a device similar to lieb engineering but from GPower called OPF Deleter so that one prevents it.