Hi all!
Fairly new here and loving it so far. I'm the https://www.northamericanmotoring.co...cked-05-s.html guy.
Seems like I've got a 19% pulley on my 05 S. What I'm wondering, is the 2 or 3 pops in the exhaust normal between shifts? Also at a stop, just rev to 3,000rpm and half way back down it does the pop pop then smooth idle.

 

Yup normal! MINI programmed it in to the ecu to give you a cool exhaust burble during downshifts and deceleration

 

It's a beautiful thing, both generations do it. R56 is a bit quieter, though, since its a turbo.

 

'Love that sound!

 

you should hear it on my car....

i have an open exhaust... its fukin loud and it pops like CRAZY and very loud pops

 

Did you guy get an upgrade? I thought that the 01- 6/03 did not have it and they started to incorporate into the 6/03 for the introduction of the 2004 model year? I have a early year and it did not make the sound until I got called in for an emissions recall and they gave me a late 03 ecu upgrade? At least that is what the dealership told me.

 

AWESOME!! Thanks for the help!!
This whole ime I thought I had larger injectors and the wrong tune.

 

my 79 does it

and there ain't no 'programming' here

so go back to the soup bowl as to cause . . . .

think about it??? Harley's do it too and they gots no blowers...

I've aked why???? And 3 years waiting have no answer ... not even an attempt at a BAD answer

so, why?????

as far as "they designed the exhaust that way"

did 'they' design the twin DTM on my 79?

 

Back in the day we used to call that sound "tumble over". Now it's called burble.

My early cars were all products of the 60's and 70's. They all had carburetors for fuel systems. The ones with a manual transmission would make the pop, pop, popping sound when I would coast in gear, especially at higher RPMs.

When you took your foot off the accelerator pedal, the butterfly plate in the carb returns to an idle position, which allows a small amount of fuel to pass through the engine unburnt and into the hot exhaust system. If conditions are just so, there's enough heat in the exhaust system to ignite this excess fuel, making the popping sounds.

Or at least that's what some old time mechanics told me when I asked.

Maybe on the later versions of the MINIs, instead of turning off the fuel injectors completely when coasting, they are "programmed" to leave the injectors slightly open to produce the burble.

 

Winner! When our cars pop the ECU squirts a little fuel into the engine and retards the ignition to a few degree before top dead center. Since the ignition event is so late most of the fuel is unburnt (or still burning) when it goes into the headers making popping sounds. It's pretty cool that BMW actually did that though, as it meant they felt the slight sacrifice in fuel economy was worth adding this feature.

Similar strategies can also be used to keep a turbo spooled when employed a bit more aggressively.

 

I love the sound, but wonder what it's doing to my cats...

 

My cats do this every time the car burbles



I don't think there's any lasting damage to them, though.

 

SU carb ain't got no butterfly ....

so I'll give it a maybe

the description sounds more like a backfire to me

the burble doesn't sound like an ignition pop

 

OK, I'll give you that one. But they do have an idle circuit that dumps fuel into the engine as you coast.

What I'd like to know if it would be possible to program the ECU to leave the injectors open a small percentage when you coast rather than turn them completely off?

 

I have always known it to be unburnt fuel entering the hot exhaust and igniting causing the pop. I get everything from small little pops to an occasional big one. Many cars do it, including 300k super cars and if they do it you know its not a bad thing. Nothing to worry about.

 

LOL, BlimeyCabrio!
I love cats and my "burble"