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B58 cold start delete TOO quiet?!

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8.6K views 12 replies 7 participants last post by  Sticky1098  
#1 ·
So I finally picked up my K+DCAN cable from the Post Office yesterday (4 days shipping from USA, a week sat waiting in the UK after payment of customs fee :censored2: ), and applied the MHD 'Cold Start Noise Reduction' to my stock map with MPE and front silencer delete...

Bloody hell! I have read other posts about the 'magnitude' of the change, but I was still shocked this morning by just how much quieter a stone cold start is. As confirmed by MHD, the car started fine as usual and with a somewhat elevated engine speed before settling down to warm idle, but the engine/exhaust noise is a fraction of what it was. Very next-door-neighbour friendly, but almost unbefitting of this car!

It's not often you can moan about something being too good, but I would ideally like half that volume back, or as noted by others some sort of cabin override to choose when to let rip. Maybe I will console myself with the Stage 1 map.
 
#5 ·
99% sure yes; I also forked out for the Stage 1 map but did not flash it (yet). The Cold Start Noise Reduction and other adjustments (burbles etc.) were available from the Stage 0 stock map screen.
 
#7 ·
I used to like it, but since getting the MPE (or maybe it was like it before), it sounds almost as if it's blowing.

Must be annoying for the neighbours (and my family) when I fire it up at 5am :lol2:

I'm seriously considering the mod if I can find the spare cash. Just wondering how much impact it will have on emissions and the cat if it's not warming up quick enough.

I've got a JB+ so maybe I'll sell that and get a stage 1 map with the bm3
 
#8 ·
From reading other threads, and my own observations, as soon as you touch the throttle this process is interrupted and the exhaust note quietens - but if you pull up to a junction while still cold it resumes. Therefore, whatever benefit to the environment this brings is lost if you just start up and drive away for a few miles. This behaviour also implies that it is more about 'efficiency' than protection/longevity of the cats themselves.
 
#9 ·
After a centre silencer/resonator delete the cold start sounds bloody awful and I can't wait to have it mapped out
 
#11 ·
Sticky1098 said:
I've just flashed my car with mhd, with cold start deleted did you find it smells rich till the car has warmed up anyone ?
No, I am MHD s1 and can't say I've noticed this....although I haven't really been looking for it to be honest.
 
#12 ·
Sticky1098 said:
I've just flashed my car with mhd, with cold start deleted did you find it smells rich till the car has warmed up anyone ?
A B58 smells rich when cold starting any time. I don't think CSD changes anything to do with that. My understanding is cold start holds open the wastegate when idling. A turbocharger is a good silencer, so with wastegate open you get more sound.

Regarding emissions, it will have a very small effect. By bypassing the turbine, more heat enters the catalytic converters sooner, making them work earlier. But you are talking seconds not minutes of difference.

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#13 ·
There is also some sort of difference in the maps if you have xhp flash there's a different option to choose from so I'm on that at the moment and what happens if a stage 2 map is put on with a normal downpipe ?