Popping exhaust question
Discussion
Hi everyone.
I'll be soon replacing an exhaust on a BMW mini cooper (not S) as the rear box has a hole in it.
I noticed that when the engine is in overrun it makes a popping noise. I appreciate what causes this noise and why it does it. I read online that cooper S' are notorious for it but no mention of plain coopers/ones.
However it go me thinking. Do the majority of road cars make this popping noise when in overrun and is it just a case that exhaust systems are so quiet these days that you don't hear/notice them on typical road cars. The reason I ask is that when the exhaust was in good nick we've never noticed it making the popping noise. I'm wondering if its always made this noise and the hole just makes it noticeable.
I read somewhere online that the hole maybe sucking air when the exhaust pulse flies past and this air helps promote the popping (i'm guessing providing some more oxygen?) I didn't really understand this theory though. Could someone please explain it.
Anyway I guess I have too much time kill at work thinking about these things!
Cheers
RS
I'll be soon replacing an exhaust on a BMW mini cooper (not S) as the rear box has a hole in it.
I noticed that when the engine is in overrun it makes a popping noise. I appreciate what causes this noise and why it does it. I read online that cooper S' are notorious for it but no mention of plain coopers/ones.
However it go me thinking. Do the majority of road cars make this popping noise when in overrun and is it just a case that exhaust systems are so quiet these days that you don't hear/notice them on typical road cars. The reason I ask is that when the exhaust was in good nick we've never noticed it making the popping noise. I'm wondering if its always made this noise and the hole just makes it noticeable.
I read somewhere online that the hole maybe sucking air when the exhaust pulse flies past and this air helps promote the popping (i'm guessing providing some more oxygen?) I didn't really understand this theory though. Could someone please explain it.
Anyway I guess I have too much time kill at work thinking about these things!
Cheers
RS
the popping is great! I used to live very near a S Works and that sounded superb.
I'm interested in the idea that the hole letting air in might increase the snap crackle pop. Just trying to get my head round it. I'm trying to find the link to post on here to show you guys.
That Elise being fully wrung out sounds fantastic! That overrun flash would make batman proud
I'm interested in the idea that the hole letting air in might increase the snap crackle pop. Just trying to get my head round it. I'm trying to find the link to post on here to show you guys.
That Elise being fully wrung out sounds fantastic! That overrun flash would make batman proud
Special K said:
RobCrezz said:
Garlick said:
I can't explain it, but my TVR can do 'pops' loud enough to make pedestrians jump out of their skin
Same here with my car. I never make it pop when I go past a bus stop, ever.One of my finest motoring moments was the day I caused a minor security alert outside the Old Bailey by swinging round the corner from Holborn in my old Porsche 924 just as the over-sized after-market exhaust let out a couple of very loud bangs. The sight of the assembled press corps ducking for cover is a memory that will stay with me for ever.
Garlick said:
Special K said:
RobCrezz said:
Garlick said:
I can't explain it, but my TVR can do 'pops' loud enough to make pedestrians jump out of their skin
Same here with my car. I never make it pop when I go past a bus stop, ever.My bike does it spectacularly. All due to carbs and a leaking port gasket (which is an engine out job to fix). Bit of fuel into the hot pipes mixed with some air from the leak and it gives some really spectacular noises (and I'm told flames too).
Of course I'd never ever leave it in too low a gear with lots of revs to make it pop and bang on purpose, oh no.
Of course I'd never ever leave it in too low a gear with lots of revs to make it pop and bang on purpose, oh no.
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