Finally...
A few spare minutes to quickly share some details on my new (improved!) exhaust set up.
With a long slog from MachineMonkey, and some (significant) time spent swapping them over - I now have my own custom built exhausts to my design, with MM improvements. The system is based on that of Exdos, and a few tweaks from chatting to various custom exhaust shops, googling and MM himself.
The aim:
Take a stock exhaust, make it more fitting to the style, performance and design of the car, and make a best effort improvement on air flow.
The method:
Using a spare OEM backbox set, remove all S-bend piping, replace with a perforated central box, and some plates for guiding airflow towards the exit.
The thought being Perforated pipe removes some of the resonance, preventing too much Rasp and Drone, but allowing a more direct path from inlet->outlet you improve airflow and therefore potentially power (when combined with other airflow based mods). The bonus, and one key thing for me, was improving the sound (personal taste). IMO the OEM BMW sound is pretty tame for such a high performance car, but most aftermarket systems seem to be OTT and pretty obviously aftermarket. I wanted to improve things, but only to the extent that joe-public wouldn't know it wasn't originally meant to make that sound. So - Lower, deeper gurgle at idle, no more drone/rasp than existing, and more volume at WOT and hopefully a potential performance increase.
Some pics
Internal box side walls, and plate for airflow direction:
Sealed internal box:
Sealed external shell, Half polished:
The outcome:
Lower, deeper gurgle at idle, no more drone/rasp than existing, and more volume at WOT and hopefully a potential performance increase. :evil:
Evidently, i'm a happy bunny, and i owe MM a decent beer. The 1-2 hour refitting job probably worked out to be 4 hours in the end, thankfully i had some spare bolts/rings etc, and MM has a host of tools to make life easy (Angle grinder was required for old rusted bolts!).
Some videos - as expected they really don't show much - the extra depth and volume is barely noticeable on the video, but pretty evident when you start it, and people do seem to be more interested when i drive by at slow speed (read: interested, not angry
)
Before (cold start)
https://www.youtube.com/watch?v=2f0HmG8Bcj8
[youtube]2f0HmG8Bcj8[/youtube]
After (cold start)
https://www.youtube.com/watch?v=5m0PB8OcdPs
[youtube]5m0PB8OcdPs[/youtube]
I do have a warm start before-vid, but need to record the warm start after-vid before i put it up
What's it like to Drive?
Startup - +30% volume, deeper, more gurgle, similar to a PSE but maybe slightly less in your face. Same 'quantity' of rasp, but more aggressive when cold.
1600-2000 RPM - under load you have the usual slight drone in high gears, but motorway speeds no difference,
above 3500 RPM +20% volume
When warm - more depth, pops/bangs on overrun - (though i believe people claim this doesn't happen... pretty clearly does when this thing is hot - just not sure what is causing it!) Sounds epic. Also great fun with a bit of heel-toe b-road action
The observant will notice MM painted them black too - great choice in the end, no bollocks hanging from the back of my car now
Would i recommend? Yes! Will MM ever do them again? I doubt it - lol.
Next stop - Gruppe M.
Credits: Big thanks to Exdos, Dalecan, gwatson and of course MachineMonkey for the initial input, and the physical hard work.
A few spare minutes to quickly share some details on my new (improved!) exhaust set up.
With a long slog from MachineMonkey, and some (significant) time spent swapping them over - I now have my own custom built exhausts to my design, with MM improvements. The system is based on that of Exdos, and a few tweaks from chatting to various custom exhaust shops, googling and MM himself.
The aim:
Take a stock exhaust, make it more fitting to the style, performance and design of the car, and make a best effort improvement on air flow.
The method:
Using a spare OEM backbox set, remove all S-bend piping, replace with a perforated central box, and some plates for guiding airflow towards the exit.
The thought being Perforated pipe removes some of the resonance, preventing too much Rasp and Drone, but allowing a more direct path from inlet->outlet you improve airflow and therefore potentially power (when combined with other airflow based mods). The bonus, and one key thing for me, was improving the sound (personal taste). IMO the OEM BMW sound is pretty tame for such a high performance car, but most aftermarket systems seem to be OTT and pretty obviously aftermarket. I wanted to improve things, but only to the extent that joe-public wouldn't know it wasn't originally meant to make that sound. So - Lower, deeper gurgle at idle, no more drone/rasp than existing, and more volume at WOT and hopefully a potential performance increase.
Some pics
Internal box side walls, and plate for airflow direction:
Sealed internal box:
Sealed external shell, Half polished:
The outcome:
Lower, deeper gurgle at idle, no more drone/rasp than existing, and more volume at WOT and hopefully a potential performance increase. :evil:
Evidently, i'm a happy bunny, and i owe MM a decent beer. The 1-2 hour refitting job probably worked out to be 4 hours in the end, thankfully i had some spare bolts/rings etc, and MM has a host of tools to make life easy (Angle grinder was required for old rusted bolts!).
Some videos - as expected they really don't show much - the extra depth and volume is barely noticeable on the video, but pretty evident when you start it, and people do seem to be more interested when i drive by at slow speed (read: interested, not angry
)Before (cold start)
https://www.youtube.com/watch?v=2f0HmG8Bcj8
[youtube]2f0HmG8Bcj8[/youtube]
After (cold start)
https://www.youtube.com/watch?v=5m0PB8OcdPs
[youtube]5m0PB8OcdPs[/youtube]
I do have a warm start before-vid, but need to record the warm start after-vid before i put it up
What's it like to Drive?
Startup - +30% volume, deeper, more gurgle, similar to a PSE but maybe slightly less in your face. Same 'quantity' of rasp, but more aggressive when cold.
1600-2000 RPM - under load you have the usual slight drone in high gears, but motorway speeds no difference,
above 3500 RPM +20% volume
When warm - more depth, pops/bangs on overrun - (though i believe people claim this doesn't happen... pretty clearly does when this thing is hot - just not sure what is causing it!) Sounds epic. Also great fun with a bit of heel-toe b-road action
The observant will notice MM painted them black too - great choice in the end, no bollocks hanging from the back of my car now
Would i recommend? Yes! Will MM ever do them again? I doubt it - lol.
Next stop - Gruppe M.
Credits: Big thanks to Exdos, Dalecan, gwatson and of course MachineMonkey for the initial input, and the physical hard work.
