Model Y road noise/rumble primary cause

[ElectricBro]

Your FUD is laughably weak and isn't going to work... Only Tesla is building their vehicles with mega-castings. Any new EVs or normal ICE vehicles that don't have megacastings are outdated and will suffer on price/margin and performance. All Teslas are top-notch high-performance vehicles and performance will only increase with megacastings reducing weight.

Everyone drives over speed bumps or curbs to get into drive ways. Front tires hit the speed bumps before the rears. Many times you don't hit perfectly square and one side hits before the other. Roads aren't flat and front/rear and left/right experience different loads all the time.

Those Teslas drivers were putting enormous loads (torsional or whatever) on their vehicles when they smash over curbs or dive into catch berms at high-speed (100+ mph). The glass roof stays intact ("this is the reason why we see so many glass roof crack complaints") so your entire premise is complete nonsense.

You did not read my previous post carefully, I repost it here for your reference, hope it answers your confusion:

It takes certain rounds (thousands? hundred thousand?) of the stress cycle with enough stress level to make the crack occurred in the glass ceiling. That is the reason why not all of us observe this symptom in our cars, or in one single specific diagonal test. And it is possible that Tesla has changed the bonding formula which has more elasticity between the car frame and glass, to not let the glass ceiling be responsible for load, in exchange for less torsional rigidity.

To summarize, no matter how we argue, it does not change the fact that M3/MY lacks torsional rigidity compared to other vehicles.

Elon likes to actively advertise with concrete data when his products have advantages (for example, xx seconds from 0-60, 1/4 miles, xx rating for yyy test etc. ) - in fact not only for tesla, all automakers are doing the same thing (why not?).

For rigidity, whenever there is any new model or a new generation of the model, most automakers will mention the new model's rigidity data, or at least, how many percent it is better than the previous generation/competitors. However, we never saw Tesla mentioned any of such data; they even do not want to proactively bring up this topic. Why?

 

[ElectricBro]

Also one related topic I would like to bring up is, single-piece casting does not necessarily mean higher rigidity, especially for aluminum casting since this type of alloy is less stiff/more flexible compared to UHSS or hot-stamped UHSS. Single-piece casting is mainly for lightweight and lower cost (after production volume has been ramped up); rigidity can be up or down, depends on the actual formula of the alloy and the geometry of the casted piece.

With that being said, most automakers are switching away from using casted aluminum for car body's cabin structure and using UHSS/aluminum/carbon fiber hybrid material composition (recent examples are Audi A8 and the Acura NSX), to achieve better weight and rigidity at the same time - but the downside is higher cost.

The auto industry has utilized one-piece subframe casting a long time ago (as early as 1998). For example, Toyota has started to use single-piece casted subframes around the mid-2000s (actual development work started ~ yr of 2000), one of its usage is in the 3gen GS/2gen IS; while the MB W212 E class is using welded-steel tube subframe. However, the Lexus does not achieve better rigidity quality (local and global) compared to the E class.

 

[PhotonMiles]

See: Ear pain/Pressure help

Insulating the bucket and hatch may not be worth the effort.

One more thing of note, after fixing the hatch (car was unbearable with the hatch buffeting), the car seemed to get quieter over the first few thousand miles. I'm not sure if the suspension became a little more compliant as it broke in, the tires broke in, door and hatch gaskets settled in, or something else.

I noticed the low frequency resonating was louder the other day, so I lowered my tire pressure back to 38 and it's mostly gone again. (Cold tire pressure crept up to 42 because of the warmer weather.)

Would you be willing to post a video clip of driving at approx. 30MPH on less-than-perfect roads so I could do an FFT analysis on it? I’d love to see the results.

 

[MY-Y]

Would you be willing to post a video clip of driving at approx. 30MPH on less-than-perfect roads so I could do an FFT analysis on it? I’d love to see the results.

I didn't have scientific rigor on these tests (speed and road are likely different), but the shape of the current curve (above) can still be contrasted with the original shape (below) for insight.

 

[PhotonMiles]

I didn't have scientific rigor on these tests (speed and road are likely different), but the shape of the current curve (above) can still be contrasted with the original shape (below) for insight.
View attachment 671732
View attachment 671733

Thanks for this! It certainly does appear that the primary spikey resonance is more tamed in your "after" recording; it's still present, but no longer standing out above the rest.

All other recordings I've seen/done from inside a Model Y have a very distinct low-frequency resonance clearly peaking above any other frequency. I think part of the reason it's so annoying is that it's like a constantly ringing bell, just at a very low frequency.

I've measured the interior noise of a 2006 Subaru Forester for comparison and it's not significantly quieter overall, but the low frequencies are much more "smeared" with no distinct resonance, which I think is the main reason it's not annoying for passengers in the same way. It seems like your treatments on your Model Y may have brought it to a similar space - not necessarily massively quieter overall, but since there's no longer a distinct ringing frequency it's probably much less noticeable.

 

[Pianewman]

ElectricBro: Just saw a YouTube, 7-seat MY. Owner says the interior is MUCH quieter than his earlier production MY.

Any thoughts on how the addition of additional mass (3rd row) could impact on the resonance? Is it possible the bracing for the 3-row MY is different enough to help stabilize the rear structure and keeps it from resonating? Or is it simply better QC in manufacture?

 

[dosticks]

Just a note here from recent buyer to say that the issue still exists.

My first trip in the Model Y was so boomy, it made my ears ring and was just fatigued from the 35 mile journey. My wife later complained about it unprompted.

I adjusted the four rubber stoppers where the hatch meets the body, but if it helped it was subtle.

I have a service center appointment for mid-December. I am holding out hope they have a remedy.

One thing I don't get: if this is in intrinsic issue with Model Ys as some are arguing, why aren't more owners complaining?

 

[PecuniaNonOlet]

I've often wondered the same thing.

Something to keep in mind is the volume of the boom depends heavily on the road surface.

 

[SgtLou02]

I saw this video and it looks spot on:

 

[MY-Y]

I saw this video and it looks spot on:

That'll fix the headache inducing subsonic sadness. Rigid stops are the key to fix the 45-50 Hz resonation.

 

[Yperformance]

Eat less baked beans! It's driving me nuts. Have made ajustnents, fitted extra sound insulation on some edges. Any extra thoughts ?