This might be difficult to diagnose over the internet...

I will be crusing along in my MINI listening to that beautiful supercharger whine, but sometimes when I step on the gas, especially at higher revs, the whine (or some other noise) will kick in extra loud for a few seconds. Does this sound familiar to anyone? My R52 doesn't do this.

My first thought is maybe the supercharger belt is slipping. What would that sound like?

I don't want to muddy the waters, but it may be worth noting that the previous owner put a 17% reducer on it and the engine has not yet been tuned for it, whereas the R52 is stock.

Thanks, as always!

 

Does it sound like a normal SC wine, but louder, or is a different sounding wine?

Did this just start to happen, or has it always been like that?

have you done any service on the SC since after the previous owner put the 17% on?

You could reccord the sound and post it here to better help understand what kind of noise it is.

 

What kind air filter boxes does each car have?

A fully connected and working JCW airbox has a flap that opens around 4,500 rpm to let more whine out. Or, the R53 might still have an open airbox that’s louder across the rev range, especially towards the higher end.

 

You can check the belt tensioner and see if the belt is stretched/worn and ready to be swapped out...

Typically you should always see an entire hole visible in that middle metal strip at the top of belt tensioner....if you see half hole or less, time for new belt.

For the 17% and 19% SCP use the NAPA 060532.
For 15% SCP I use the NAPA 060535.
For Stock SCP I use NAPA 060539.

 

No tune needed for a -17% or -19% scp pulley, the DME will compensate....however eventually I installed the JCW 380cc injectors and my tech friend at dealership loaded the JCW Tuning software....with the JCW airbox....a nice upgrade.

 

I had the same issue and it was belt slippage.

 

The car with the reduction pulley might have a slightly too-large belt.

Try to gently climb through the revs, then do so quickly. If the problem follows the rapid RPM gain, that would suggest belt slippage.

 

Thanks for your input, everyone!

I have some sound recorded, I just need to figure out how to get it uploaded.

 

hey! previous owner here lol just to give some more info. The car has a new tensioner, belt and its an open filter CAI. To my searching its the open filter CAI? or the infamous throttle whistle? it also has a new Detroit tuned valve. Im curious to see what everyone thinks .

@superheavydeathmetal Unless im mistaken the noise is more noticeable at WOT? also, i miss this little car =(