Stock exhaust or modified???

[RobertZ4M]

Evening all,
Is anyone familiar with the z4m e86 stock exhaust. I have two small gauge pipes that circumvent the back box. Are these original or a later modification?

Thanks
Rob

 

[mmm-five]

They’re a later mod to increase the volume a little.

 

[RobertZ4M]

Perfect, thank you. I initially wondered if it was to reduce exhaust drone. I’ll have to find a stock M and see if there’s any difference

 

[mmm-five]

There’s more info on this thread…

A

Thread 'Exhaust Bypass Mod'

Jul 16, 2016

[youtube][/youtube]So got my back boxes back on Friday with the bypass pipe fitted along with new tail pipes. The body of the boxes were given a polish as well.

I got new tail pipes on as I couldn't get used to the larger diameter of the MM pipes I had fitted. If anyone wants some cheap almost new MM pipes then let me know

I drove the car up to AMDetails today for its correction and coating so had a good drive both plodding and exhuberent and the exhaust is just what I was after. Steady throttle revs below 3k and not a lot of difference to the standard noise but when pressing on there is...

• AlfaScozzesi
• Replies: 13
• Forum: "M" Specific

 

[mmm-five]

Perfect, thank you. I initially wondered if it was to reduce exhaust drone. I’ll have to find a stock M and see if there’s any difference

I tried to get a Powervalve system fitted, but kept getting messed about with the trial fitting (as I was going to be a test car)…and ended up going with a Rogue Engineering Diablo system instead…which you’d not like as it really drones at a specific RPM when under load - although I don’t see why you’d be spending lots of time driving these in the 2000-3000 range when pushing on

 

[RobertZ4M]

I used to a have a scooby with the ej25 engine. Oh my god the drone! I ended up paying thousands for a clever exhaust that reduced the drone down to acceptable levels.

 

[BMWZ4MC]

I tried to get a Powervalve system fitted, but kept getting messed about with the trial fitting (as I was going to be a test car)…and ended up going with a Rogue Engineering Diablo system instead…which you’d not like as it really drones at a specific RPM when under load - although I don’t see why you’d be spending lots of time driving these in the 2000-3000 range when pushing on

I thought you avoided the drone by leaving your car with you mechanic for years

 

[mmm-five]

I thought you avoided the drone by leaving your car with you mechanic for years

You've not heard my mate's voice when he's moaning - the drone from the exhaust is much more melodic.

Anyway, I'm used to fake noises now, as the 335D has BMWs 'Active Sound Design' and I can code the system to play a 4-pot diesel noise through the hifi if I want.

 

[Ed Doe]

You've not heard my mate's voice when he's moaning - the drone from the exhaust is much more melodic.

Anyway, I'm used to fake noises now, as the 335D has BMWs 'Active Sound Design' and I can code the system to play a 4-pot diesel noise through the hifi if I want.

I hope you've coded it to make v10 S85 noises instead?

FWIW my Supersprint race cans and xpipe also produce a drone 2-3k under load, but I solved this with a 4.1 FD so now it's above 3k on the motorway at 70, and noteably quicker in gear! Everyone* wins!!!


*My long suffering wife does NOT