S-Prihadi

Interesting and it answered my question which I been trying to look for an answer, to why the Bilstein B4 make a quiter ride compared to the OE SACHS on my car.



Start at 6:15


My own finding of the reduced road noise : https://mbworld.org/forums/e-class-w...lstein-b4.html
I wrote :
"I did not put much miles on the car after the shock absorber change, ony about 20 KM max but on crappy roads.
However, my driver clocked 70KM at least when picking up my kids at the aiport. He is enjoying the remarkable improvement of an obvious reduction on road noise ...so did I.

I gone thru many cars since the 80s, but I do not recall a quiter road noise from a shock absorber change.
My theory on this is : the first valving which controls the probably first 20mm or 0.78 inch of the shock bounce/rebound travel is better on the Bilstein.
Since my city roads roads surface some are really rough and uneven, I think the SACHS were not taking it well and hence more suspension noise which I thought was tire noise."

So as the engineer in the video said : Swish and Chuckle

MTS has its own damper test machine, so it makes sense and easy for them to gather data for damper alone without other mechanical influence from other components in the car.

There are some good NVH data coming out along with Electric cars getting popular.
Suddenly road noise is more offensive than ever for EV OEM and engineers.


My next itchy hand project is to reduce noise of the front wheel well............

S-Prihadi

Here is an example.
Concrete highway which is much noisier than black tarmac.
Music in cabin at low setting. You can hear me at 16 second video time , I was doing sort of what a relief whistle while car on the bridge joint ( black tarmac),
which was good joint for me and not crazy jumpy like most highway bridge joints on this trip.

Audio Recorder is the dashcam itself along with its video, which is not the best audio gain.
Video edited with 5.6dB audio gain.
If you listen well, you can hear the turn signal I am using to show I am overtaking on the right. The car and the road is a Right Hand Drive.
GPS speed is what I use and it comes from the dashcam itself, which has a good GPS chip and update speed is once per second.

Front suspension is Bilstein B4, rear is Bilstein B6.
Tires are Michelin Pilot Sport 4, it is UHP Summer tire but not crazy noisy, but also not as quiet as comfort tires.
Tire pressure front 33 psi and rear 34 psi. Front 245/40 -18" and rear is 255/40 -18"
2 person only in the car and luggage not so much, under 75KG.
At this time no added sound proofing yet on the car.

Polite 175KMH to 200KM/H or 108.7 to 124.2 MPH



Not too noisy.......