Do spacers affect the airflow?

Dr Forinor · 06-17-2018, 02:33 PM

Before fitting the spacers I never used to hear any "wind rustle" (not whistle but more the sort of noise you expect when you open your window slightly) at motorway speeds.

Since fitting them, I notice this noise a lot more and it's much more noticeable when you have a wall or a high sided vehicle close to you.

I cant find anything loose around the doors, can't see any obvious defect in the seals and scratching my head like crazy the only change I can put it down to is the spacers.

Has anyone else noticed this? Or is the culprit something else and I've just picked the wrong victim?

Watsey · 06-17-2018, 02:50 PM

I noticed a distinct difference in sound when the M Sport drilled discs were installed when I had the MPPK fitted a couple of years ago. A distinct hissing/whistling noise, especially if there was a hard surface near the car to reflect the sound.

It went completely when I installed the StopTech BBK - slotted, not grooved, discs. I haven't noticed it since.

Spacers were installed with both.

Dr Forinor · 06-17-2018, 03:27 PM

You think the dimpled areas of the M Performance discs are the cause?

Because the other part of them are slotted, same as your StopTech?

Watsey · 06-17-2018, 04:34 PM

It's the only link that I could find. Dimpled discs = noise; slotted =- quiet (as far as I've noticed).

Dr Forinor · 06-17-2018, 04:48 PM

How very interesting. Would love to see if anyone else has noticed anything.

06-17-2018, 02:33 PM	#1
Dr Forinor Captain 266 Rep 922 Posts Drives: 2015 F31 335d Join Date: Feb 2014 Location: Abrdn/Dund iTrader: (0)	Do spacers affect the airflow? Before fitting the spacers I never used to hear any "wind rustle" (not whistle but more the sort of noise you expect when you open your window slightly) at motorway speeds. Since fitting them, I notice this noise a lot more and it's much more noticeable when you have a wall or a high sided vehicle close to you. I cant find anything loose around the doors, can't see any obvious defect in the seals and scratching my head like crazy the only change I can put it down to is the spacers. Has anyone else noticed this? Or is the culprit something else and I've just picked the wrong victim? __________________ Coding. LED Front Fogs. DIY Driver Glovebox. KW Street Comfort. 15mm Rear ARB. Tarox SS Brake Lines. Motorwerks Remap. DIY Rear 12v Socket. M Performance Discs. Tarox Strada Pads. Spacers (10mm & 12mm). Head Unit USB Cable. Rear Diffuser. Rear Light Tints. Non RFTs. Last edited by Dr Forinor; 06-17-2018 at 03:22 PM..
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06-17-2018, 02:50 PM	#2
Watsey Major General 6416 Rep 8,498 Posts Drives: F31 330D sDrive M Sport Join Date: Jun 2015 Location: On sabbatical. iTrader: (1)	I noticed a distinct difference in sound when the M Sport drilled discs were installed when I had the MPPK fitted a couple of years ago. A distinct hissing/whistling noise, especially if there was a hard surface near the car to reflect the sound. It went completely when I installed the StopTech BBK - slotted, not grooved, discs. I haven't noticed it since. Spacers were installed with both. __________________ Current : F31 330sD, remapped, Ohlins Road & Track, Millway camber plates, Quaife LSD, Stoptech brakes + Pagid RSL1 pads all round, Weichers front strut brace, Eibach front & rear anti-roll bars, Michelin MP4S.
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06-17-2018, 03:27 PM	#3
Dr Forinor Captain 266 Rep 922 Posts Drives: 2015 F31 335d Join Date: Feb 2014 Location: Abrdn/Dund iTrader: (0)	You think the dimpled areas of the M Performance discs are the cause? Because the other part of them are slotted, same as your StopTech? __________________ Coding. LED Front Fogs. DIY Driver Glovebox. KW Street Comfort. 15mm Rear ARB. Tarox SS Brake Lines. Motorwerks Remap. DIY Rear 12v Socket. M Performance Discs. Tarox Strada Pads. Spacers (10mm & 12mm). Head Unit USB Cable. Rear Diffuser. Rear Light Tints. Non RFTs.
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06-17-2018, 04:34 PM	#4
Watsey Major General 6416 Rep 8,498 Posts Drives: F31 330D sDrive M Sport Join Date: Jun 2015 Location: On sabbatical. iTrader: (1)	It's the only link that I could find. Dimpled discs = noise; slotted =- quiet (as far as I've noticed). __________________ Current : F31 330sD, remapped, Ohlins Road & Track, Millway camber plates, Quaife LSD, Stoptech brakes + Pagid RSL1 pads all round, Weichers front strut brace, Eibach front & rear anti-roll bars, Michelin MP4S.
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06-17-2018, 04:48 PM	#5
Dr Forinor Captain 266 Rep 922 Posts Drives: 2015 F31 335d Join Date: Feb 2014 Location: Abrdn/Dund iTrader: (0)	How very interesting. Would love to see if anyone else has noticed anything.
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