DIY solution to deadening tire noise

[Johan]

"Having seen the Reticel foam and the way it's installed I have my own ideas about a better way to do this"

Gotta love that attitude! Looking forward to your report!

 

[David99]

To be blunt the foam doesn't makes much of a difference. The data show that as do my personal impressions driving the car. The sound meter readings are basically the same as the pre-foam installation readings. It should be noted that the Pilot Sport is a very noisy tire, to be expected I suppose for a summer performance tire. It's especially noisy on concrete and other rough surfaces and the foam seems to have no impact on that noise. I'm very disappointed, but the facts are the facts.

thanks so much for your work and efforts and sharing all your experience. It's definitely helpful. If anything, a noisy tire is the best test.

 

[invisik]

I've now been living with the Recticel foam lining my Michelin Pilot Sport 21" tires for about a week and I'm here to report both data and impressions.

Yes, thank you so much for your time and money to try this out. I was hoping for better results too.

This kinda confirms a thought I've been having... the sound is more coming from the exterior surface of the tire when it is touching the road. Which I can't believe there is much aftermarket to do about that--more of a tread design/compound issue. But if Continental is claiming 9db reduction, I'm excited to hear the results of your own formula.

What do you think about soundproofing the wheel openings? Or did Don from the sound proofing place say happen to mention anything about it?

Thanks again......

-m

 

[artsci]

This kinda confirms a thought I've been having... the sound is more coming from the exterior surface of the tire when it is touching the road. Which I can't believe there is much aftermarket to do about that--more of a tread design/compound issue. But if Continental is claiming 9db reduction, I'm excited to hear the results of your own formula.

What do you think about soundproofing the wheel openings? Or did Don from the sound proofing place say happen to mention anything about it?

-m

The question about the external noise of the tire and whether it can be dampened at all by anything on the inside of the tire is a very good question. Certainly I've not seen hard data that justify Recticel's or Continental's claims, which is why I want to do more experimentation.

Don said there was not much to be done about the wheel openings beyond what was already there.

Being an optimist, I have to say that I've become a bit of a pessimist about whether foam in any form will make a considerable difference. Regrettably I may provide my own proof that my pessimism is justified

 

[redi]

artsci,

Thanks for your efforts and honest reporting, particularly on the torture-test rough concrete road surfaces; the ones that make my Michelin PS2 almost unbearably loud (and on any other surface they are quiet).

I have been holding off on the ContiSilent and the purportedly quiet Pirellis hoping for some real comparative feadback on the rough concrete surfaces. You can't rely the marketing material as factual.

 

[green1]

I'm sorry to hear that this foam didn't live up to your hopes. I do however look forward to your future tests.

The question about the external noise of the tire and whether it can be dampened at all by anything on the inside of the tire is a very good question.

Intuitively, yes, you should be able to reduce it, tires are a hollow item, and as most people know, hollow items act as resonance chambers making sounds louder and more audible. absorbing sound within should help (a drum makes sound when you hit the outside, but if you have a towel stuffed in it there's a lot less sound)

I hope that the lack of improvement is more about the specific implementation than the overall concept.

 

[Ingineer]

A few years ago I read an article in the SAE Automotive Design magazine written by an Engineer at Michelin about tire noise. From what I remember, apparently most of it comes from little jets of air squished out in front of the contact patch as the tires move forward. The secondary noise is from air rushing in to fill the vacuum left as the contact patch lifts from the pavement.

This also explains why the coarse porous nature of black asphalt-type highway surfaces are MUCH quieter than the denser concrete.

Seems to me an Active noise cancelling system would be most effective at attenuating this. I know many luxury models are starting to have these systems. It will probably not be too long before someone makes a aftermarket kit. All you'd need is some microphones to install in the Headliner and a DSP with some well written code that could output the "antinoise" signal to the speaker amps. If you've ever used a good pair of noise-cancelling headphones on a plane, they massively reduce all the white and pink background noise.

 

[DavidB]

While I'm not going to say that the foam makes no difference on my 19" wheels, I do need to admit that my initial report was too positive.

Positive: The foam reduces a lot of general tire noise. Overall, the car is quieter and I'm glad I've participated in this experiment.
Negative: There are frequencies that aren't getting much (if any) dampening. As a result, I'm much more aware of those frequencies, and am finding them annoying.


Next step in my quest to make my car quieter will be to get equipment to specifically identify the noisy frequencies, and to investigate into what products will absorb or block those frequencies

 

[artsci]

I installed my own foam solution today in my Pirelli Cintauro 20" tires. I used the kind of acoustical foam that's used in anechoic chambers. Attached it with contact cement. The whole job took about two hours, most of which was waiting time for the cement to dry before the foam was glued into the tires. I'm hopeful this will provide a more effective solution than Rectical's.

The tires go back on the wheels and the car Thursday am. I'm off to the Kennedy Space Center for a Space X launch that weekend so I won't be doing enough driving to report results until the week of the 4th.

Will post photos of the install soon.

 

[artsci]

This morning the 20" wheels with the foam-lined Pirelli Cinurato tires were mounted on my Model S. Remember, I used my own foam and installed the foam myself. When I took it out for a test drive the road noise was noticeably reduced for an already relatively quiet tire. But when my speed reached over 50mph the vibration was intolerable (this did not happen with my Recticel-lined Michelin Pilot sport 21s). The wheels/tires had been balanced before installation on the car but the shop told me it took far more weight than normal to balance them -- not a good sign. So it appears the foam I chose works very well but DYI installation is not doable, as the perfect alignment of the foam in the tire is evidently critical to balance.

So I now consider my experiment a failure. The foam considerably reduces road noise but I'm sorry to say that DYI installation appears to be unfeasible.

 

[green1]

So it appears the foam I chose works very well but DYI installation is not doable, as the perfect alignment of the foam in the tire is evidently critical to balance.

So I now consider my experiment a failure. The foam considerably reduces road noise but I'm sorry to say that DYI installation appears to be unfeasible.

I wouldn't consider it a failure as much was learned. I would say that the next step is to look in to other mounting options for your foam, could a specialist of some form find a good way of doing the foam mounting? is there a different adhesive, or different method of installing it, or other procedure difference that could make a difference?

The biggest successes come from the biggest "failures", these are all learning experiences.

Thank you very much for your work on this, but I refuse to call such a phenomenal learning experience a "failure"

 

[Johan]

Very interesting Rick!

From working with the foam, do you suspect it could shift within the tire with time even if it was perfectly placed and balanced to begin with? If not then factory mounting of this type of foam could potentially be great?

 

[AlMc]

Rick.....As was mentioned up thread..Not a failure..I appluad the effort and feel that it is a first step in improving the sound level in an already quiet car. Thanks

 

[artsci]

Very interesting Rick!

From working with the foam, do you suspect it could shift within the tire with time even if it was perfectly placed and balanced to begin with? If not then factory mounting of this type of foam could potentially be great?

So I can still use the 20" tires they are taken off the rims and the foam removed early next week. So we'll know if the foam moved around, although I doubt that. My shop and I believe the balance problem was caused by the foam not being perfectly centered over the tread.

In the meantime, so I can drive my car, I had the 21's reinstalled.

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I wouldn't consider it a failure as much was learned. I would say that the next step is to look in to other mounting options for your foam, could a specialist of some form find a good way of doing the foam mounting? is there a different adhesive, or different method of installing it, or other procedure difference that could make a difference?

The biggest successes come from the biggest "failures", these are all learning experiences.

Thank you very much for your work on this, but I refuse to call such a phenomenal learning experience a "failure"

Thanks. You've anticipated my question as well -- is there a way to install the foam so that it's perfectly centered? Going to think about that. There's probably a way.

 

[mdevp]

I am really sorry that it did not work out. But I respect you so much for attempting such an experiment, spending your own hard earned money and time. Add that to explaining your process every step of the way, and my deference is even higher than before. Thank you.

 

[Ingineer]

It's too bad there's no easy way to try it mounted to the rim. It would need less foam to cover the area, therefore less weight and since it's closer to the axis, less chance of it affecting dynamic balance.

 

[AmpedRealtor]

Does anyone here recommend the Pirelli Cinturato P7 as a less noisy alternative to the Michelin Primacy? I've read lots of good reviews of that tire being very isolating, which I want, and very quiet.

 

[artsci]

It's too bad there's no easy way to try it mounted to the rim. It would need less foam to cover the area, therefore less weight and since it's closer to the axis, less chance of it affecting dynamic balance.

With the foam mounted on the rim centrifugal force works against the stuff staying attached. It would probably end up being a mess.

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Does anyone here recommend the Pirelli Cinturato P7 as a less noisy alternative to the Michelin Primacy? I've read lots of good reviews of that tire being very isolating, which I want, and very quiet.

I have no experience with the Michelin Primacy but I swear by the Pirelli Cinturato P7. It's a very quiet tire.

 

[jerry33]

I have no experience with the Michelin Primacy

The Primacy are very quiet if the pavement is smooth--this is true even when they have little tread left. Here in Texas, smooth roads are not often the case due to the large aggregate found in many rural highways. I doubt that anything less than 10 cm of acoustical foam surrounding the entire car will help (though I'm willing to try anything that appears promising). That said, there are many cars that exhibit more tire noise on those kind of roads.

 

[Merrill]

The Cinturato P7 does not come in a 21, which Primacy are you talking about. I need a quite tire for my 21,s.