Pirelli Noise Canceling Tire

Status
Not open for further replies.
Joined
Jan 31, 2006
Messages
4,440
Location
Idaho
"...........Pirelli claims the innovation—being pitched as "Pirelli Noise Cancelling System"—can reduce the noise heard by those inside the car by 2 to 3 decibels, or roughly half.

With this development, Pirelli is addressing noise caused by the vibration produced when air inside the tire is compressed as the tire is squashed against the road. This noise is transmitted from the tire to the wheel hub and eventually reaches the inside of the car's cabin via the steering and suspension components.

The polyurethane foam sponge is designed to absorb these vibrations, the tire maker said, and thus reduce the amount of noise passed through to the cabin..........."

http://www.tirebusiness.com/article/2013...-with-pu-sponge

I could use a set of these on my Subaru!
 
^^^Times a dozen!

Any of us with wider lower profile tires know about tread noise, it can get really annoying with certain road textures and certain tires.
 
Originally Posted By: SubLGT
"...........Pirelli claims the innovation—being pitched as "Pirelli Noise Cancelling System"—can reduce the noise heard by those inside the car by 2 to 3 decibels, or roughly half.

What about noise heard outside of the car? I'd assume that would be reduced, too.

If you live near a busy highway, most of the hum you hear these days is actually generated by rolling tires and not as much by the engines. It would be really cool if that noise could be reduced.
 
I seen this talked about for about 10 years from various tire manufacturers, so this is nothing new. I think what is different is that Pirelli finally talked someone into accepting this as part of a package.

What that insert does is absorb the noise bouncing around inside the air chamber of the tire - the air chamber acting like a resonance chamber amplifying certain frequencies peculiar to the size of the chamber - and perhaps that is why Pirelli was able to sell it. It addressed a particular problem.

Will it reduce the noise to the outside? Yes, the part that is generated by the air chamber echoing through the sidewalls.

Do I think it cuts the noise level in half? Absolutely not! It might cut certain frequencies in half, but the overall noise level would only be cut a little - which is why this hasn't been adopted before.
 
maybe they are saying that the certain frequency's that resonate through the passenger compartment are cut in half?
(with windows up obviously)
 
I quieted the Bridgestones that came on my 07' Impreza. I came across patents describing why tires make noise, and how to design to avid it. Didn't want to replace the tires on a new car, so tried to modify the tires. The patents said that tires make noise in many ways. One being the grooves around the tire, and breaking them up into different lengths that aren't equal. Said the grooves compresses and release the air in them as the tire rolls on the road, Said the tread blocks also slap the roadway, and the curved tire creates a furn shape with the flat road amplifying the noise.

I figured breaking up the length of the groves around the tires would help so put some black rubber cement in the groves at random distances from the previous ones, and it helped. Before the noise was very annoying, and now I don't even think about it.
 
Originally Posted By: VinceF
I quieted the Bridgestones that came on my 07' Impreza. I came across patents describing why tires make noise, and how to design to avid it. Didn't want to replace the tires on a new car, so tried to modify the tires. The patents said that tires make noise in many ways. One being the grooves around the tire, and breaking them up into different lengths that aren't equal. Said the grooves compresses and release the air in them as the tire rolls on the road, Said the tread blocks also slap the roadway, and the curved tire creates a furn shape with the flat road amplifying the noise.

I figured breaking up the length of the groves around the tires would help so put some black rubber cement in the groves at random distances from the previous ones, and it helped. Before the noise was very annoying, and now I don't even think about it.


Just an FYI:

Short lengths generate high frequencies - which are heard as noise - and long lengths generate low frequencies - which are felt as vibrations.

The big issue from a design point of view is the affect noise reduction strategies has on wet and snow traction. Usually, this is done in reverse - the traction properties are decided first and the noise reduction techniques applied last. But the best strategy to noise reduction is more along the lines of not having a lot of elements the same size. Spread the size of the elements over a large range and the noise isn't concentrated in one frequency range.
 
Last edited:
The idea was, not to have all the sound/noise generated at one frequency, that would increase the noise level, but to spread it over different frequencies.

What's with the name CapriRacer? Is that from the Ford euro imports? I had a few, and my fav was the one with the 1.6l Kent motor because it was light, and Ford did a lot with it. Lotus had some mods for it, twin OHC, turbo, etc I wanted to get, but found about them late in the cars life. That made me want a small motor with a lot of power, then Ford came out with the 84-86 turbo 4cyl Mustang SVO. I got messed up so couldn't get one, but still want one.
 
Originally Posted By: CapriRacer
But the best strategy to noise reduction is more along the lines of not having a lot of elements the same size. Spread the size of the elements over a large range and the noise isn't concentrated in one frequency range.


Human hearing tends to focus on the frequency or pattern that stand out rather than the white noise in the background.

My concern is, what if the tires are worn unevenly, will that make certain frequency stand out?
 
Originally Posted By: PandaBear
Originally Posted By: CapriRacer
But the best strategy to noise reduction is more along the lines of not having a lot of elements the same size. Spread the size of the elements over a large range and the noise isn't concentrated in one frequency range.


Human hearing tends to focus on the frequency or pattern that stand out rather than the white noise in the background.

My concern is, what if the tires are worn unevenly, will that make certain frequency stand out?


Yes, but what is going on is that a completely different frequency pattern is being worn into the tire. Some truck tire guys traced some of this irregular wear in truck tires to harmonics on the order of 13th to 17th (if I remember correctly), which is NOT a frequency that is naturally occurring in the tire. I think they were looking at the way road surfaces interact with tires as a way to reduce this.

Originally Posted By: VinceF
........What's with the name CapriRacer? Is that from the Ford euro imports?....


Yup. I raced early 70's Capri's in the late 1990's- and still have the last one. It broke at VIR in 2001 and I never got it back together. Now that I am retired, I'm torn between fixing it or junking it.
 
Goodyear and Dunlop have joined the noise reduction party. Goodyear has SoundComfort technology, and Dunlop has NoiseShield technology.

"...Goodyear’s new “SoundComfort” technology features an open-cell polyurethane foam element attached to the inner surface of the tyre. The technology dampens the Tyre Cavity Resonance (TCR) sound peak, generated when the tyre rolls over a surface, by up to 11dBA and enables an vehicle interior noise reduction of up to 4dB, making the vehicle cabin significantly quieter across a large range of vehicle speeds……….."

http://www.tyrereviews.co.uk/Article/Is-this-the-future-for-quiet-comfortable-tyres.htm

http://www.tyreblog.co.uk/2014/gear-up-f...nlop-56449-2124
 
Originally Posted By: SubLGT
Goodyear and Dunlop have joined the noise reduction party. Goodyear has SoundComfort technology, and Dunlop has NoiseShield technology.

"...Goodyear’s new “SoundComfort” technology features an open-cell polyurethane foam element attached to the inner surface of the tyre. The technology dampens the Tyre Cavity Resonance (TCR) sound peak, generated when the tyre rolls over a surface, by up to 11dBA and enables an vehicle interior noise reduction of up to 4dB, making the vehicle cabin significantly quieter across a large range of vehicle speeds……….."

http://www.tyrereviews.co.uk/Article/Is-this-the-future-for-quiet-comfortable-tyres.htm

http://www.tyreblog.co.uk/2014/gear-up-f...nlop-56449-2124


The idea of using foam inside a tire to reduce noise has been around for over 30 years.

With the new European regulations on noise, these technologies are starting to be applied. Before, there wasn't a strong enough push to offset the cost and other problems.

I expect this to come and go. I think there will be lots of problems - and one of them will be the nature of road surfaces. Road macrotexture has a MAJOR impact on tire generated noise - more so than what this foam will be able to fix.

Besides, the foam is mostly for the passenger compartment. I think the affect on pass-by noise is minimal.
 
Toronto had a couple sections of the 401 hwy paved with noise reducing asphalt a few years ago. It was quite dramatic how much quieter it was in the car and especially in the rain. I assume it wasn't "cost effective" as its not commonly used AFAIK.
I think its the heavy truck traffic that really prevents a good quiet pavement to be used.
Here's a engineering paper on the subject
http://www.bv.transports.gouv.qc.ca/mono...ntal_choice.pdf
 
Originally Posted By: IndyIan
Toronto had a couple sections of the 401 hwy paved with noise reducing asphalt a few years ago. It was quite dramatic how much quieter it was in the car and especially in the rain. I assume it wasn't "cost effective" as its not commonly used AFAIK.
I think its the heavy truck traffic that really prevents a good quiet pavement to be used.
Here's a engineering paper on the subject
http://www.bv.transports.gouv.qc.ca/mono...ntal_choice.pdf


I was amazed at how stubborn paving people are when I've talked to them about changes in asphalt mixtures. Not only are they resistant to change, but they actively find fault even when the specs for the job change to a new type and they have no choice but to use the new material.

Complain, complain, complain. Like a bunch of old ladies. They refuse to adjust the paving machine. They blamed spillage on the new material. They argued about traction (even though they had no idea what the traction properties were.)

It was amazing.
 
Here is a technical article on the use of "tire cavity microphones" for measuring noise levels.
http://www.tiretechnologyinternational.com/articles.php?ArticleID=384

"…….The work reported here shows how tire cavity sound pressure levels can be used to predict both the far field radiated noise and cabin noise levels. In addition, the often difficult and time consuming task of road noise route tracking through the vehicle structure can be simplified using TCM data. Using TCM data it should be possible for OEMs to both specify and match tires to vehicles enhancing customer satisfaction……….."
 
Falken has announced their Silent Core noise reduction technology. Similar in principle to what is already available.

"...Falken Tire, together with its parent company Sumitomo Rubber Industries (SRI), has developed a patented solution called Silent Core, which reduces noise thanks to a layer of ether-polyurethane foam material that’s applied to the inside of the tire carcass…"

http://www.autosphere.ca/tirenews/2015/09/30/falken-tire/
 
Status
Not open for further replies.
Back
Top