Cabin noise.

[duncanireland]

Try adjusting the rear boot bump stops a little - I noticed an issue similar to what I think you're describing and it helped for me.

 

[AndrewT]

Overall I'm very pleased with the lowish noise levels in my 2009 2.9 Cayman which I purchased a month ago. There is something though that aggravates my tinnitus and that is what I can only describe as a sort of drumming/throbbing noise very similar to the effect you get on some cars if you drive with just one window open. The noise doesn't seem to bother my wife so it may just be my sensitive hearing that makes me more susceptible.

My feeling is that the noise is a result of tyres and firm suspension and is probably common with Caymans but I'd be interested to hear whether other owners have noticed the same thing. It is running on 19" Bridgestone tyres but I have also driven with 17" Bridgestone tyres and noticed no difference.

I will of course mention this noise when I have the car serviced later this month.

Thanks, Andrew.

 

[Motorhead]

Andrew,

I have a feeling that your unfortunate condition does give you an increased awareness of noise, particularly in the enclosed enviroment of a vehicle cabin.

Now retired, I spent my working life in sound and vibration consultancy, much of which in vehicle chassis and powertrain development, so I'm familiar with road-induced noise such as that which you describe. One source of road noise at certain speeds is the generation of low frequency standing waves in the tyre cavity [think of the space contained by the wheel and tyre carcase as a tube] which can set up sypathetic resonances in the suspension and/or the body and this could be what you're hearing.

I run a 2009 Cayman S but it's fitted with 19" Pielli P-Zero tyres and I haven't noticed the problem you describe, so it may well be due to the Continental's tyre construction and tread pattern. Other than trying the very expensive option of changing all your tyres, all I can suggest is that you find a tyre factor who offers a nitrogen fill. This will have the effect of changing the tyre cavity modal frequencies and hopefully detune the system. Also, just as an experiment, you could try changing the tyre pressures to see whether or not this has an effect with a standard air fill.

I should also say that you should confirm that the problem is road-induced by running the car in neutral at the condition to ensure that the powertrain isn't a contributor, or indeed the cause of the problem.

Hope that's of some help in finding a solution.

Jeff

 

[s999sws]

When I got my 2010 Cayman 2 years ago, it had 18 bridgestones on it and I was really concerned about the trye noise and harsh ride. Last year I fitted Michelin PSP2 and what a difference!

much quieter with a big increase in ride comfort. They are also better in the wet, my bridgestones used to slide about a lot.

the wear is as good as bridgestones, if not better.

BUT, I am using 18 inch wheels. I would only have gone for 19 if the car had PASM.

Cheers

steve WS

 

[AndrewT]

Thank you for your replies Duncan, Jeff, and Steve.

I'll look at the rear boot bump stops but I think that Jeff has hit the nail on the head attributing the noise to generation of low frequency standing waves in the tyre cavity as although I didn't mention it in my post I too thought the noise sounded similar to that which you get when bouncing a wheel & tyre.

I'll try a few tests such as running in neutral to eliminate the power train, adjusting the tyre pressures, and then getting the tyres nitrogen filled. I'm due for a set of new tyres in the next few months so that will present an opportunity to move from the Bridgestone Potenza RE050A to something else which may be quieter.

My car is no longer under Porsche warranty so I don't think I'll be compelled to buy 'N' rated tyres (unless that presents insurance problems) which my open up a wider range of tyres I can choose from.

Thanks, Andrew.

 

[tscaptain]

Thanks to many years in aircraft I have tinnitus too. My own experience is that Porsches are not tinnitus friendly and no amount of fiddling with different tyre makes, filling with nitrogen ( mine are), pressures etc will make a significant reduction in low frequency road noise. The 997 is particularly bad in this respect. There have been moves a foot for some time to introduce noise cancelling in the cabin via the speaker system but still some way off, I fear. Sent you a PM Andrew

 

[Buddy]

After spending most of my working life in machine shops and aerospace test facilities I suffer from Tinnitus too, a common thing for retired engineers, I also run on Bridgestone 19" tyres and found them to be noisy, unfortunately I can't say if other tyre makes are better in this regard as I hadn't got the Tinnitus then but certain road surfaces are worse than others and when I've driven on the German Autobahn it is obvious that their road surfaces generate far less noise maybe there is something with the Bridgestones which make them so much worse as I only noticed the tinnitus after fitting them but I consider the poor ( probably cheap ) road surfaces in this country to be the prime cause otherwise when I come to a good surface the noise level would be higher.

Taken from the FAQ section:-

Bridgestone N0 & N1 235/35R19 71Db Bridgestone N0 & N1 265/35R19 72Db Michelin N2 265/35R19 70Db Michelin N2 235/35R19 70Db Continental N2 235/35R19 73Db Continental N2 265/35R19 75Db

So Michelin best of those listed but no note on the Pirelli tyres approved for later models.

 

[AndrewT]

I recently had my 6 years old Bridgestone tyres replaced by a set of new Michelin Pilot Sport PS2 tyres.

Has it improved the noise levels in the cabin? Overall I would say yes it has improved, but on some road surfaces such as those dressed with granite chippings it is as bad as ever or possibly worse.

Having visited the Silverstone Classic last weekend and holidayed nearby for a week I've covered quite a few miles in my Cayman and much of the time the noise levels have been very acceptable bearing in mind it is a sports car. I continue to be impressed with the cabin comfort, the more than adequate power, the precise handling, and the lovely howl of the engine when accelerating - it's all so much more civilised than my previous TVR Griffith.

 

[Motorhead]

That's a shame you're still experiencing some problems Andrew, even with the new tyres.

Just a thought, but have you tried using some in-ear attenuators to alleviate the problem; something relatively inexpensive such as these:

[link=http://www.amazon.co.uk/Alpine-MusicSafe-Filter-Plugs-Musicians/dp/B000VO8PR0/ref=sr_1_2/276-1284045-7405619?ie=UTF8&qid=1438434357&sr=8-2&keywords=ear+plugs+musician]http://www.amazon.co.uk/Alpine-MusicSafe-Filter-Plugs-Musicians/dp/B000VO8PR0/ref=sr_1_2/276-1284045-7405619?ie=UTF8&qid=1438434357&sr=8-2&keywords=ear+plugs+musician[/link]

I use them for hard rock and metal [very loud.!] music gigs and have found them to be good, and they're also comfortable to wear. They come with three exchangeable acoustic filters, so you can select the one most suitable.

Good to hear that your condition isn't stopping you from enjoying an excellent car.

Jeff

 

[AndrewT]

Hi Jeff,

Yes I have tried some of those in-ear attenuators and they do alleviate the problem but I'm not keen on the slightly 'detached' feel that they cause. Overall the current noise level is something that I can live with and isn't stopping me enjoying my car.

 

[Motorhead]

Yes, I can understand that Andrew; although I confess that I've never used them in a car.

That reminds me of the headset I used for in-car binaural noise measurements, the little blue ear cones being particularly uncomfortable for continuous use despite the claim of "High wearing comfort" in the blurb:

[link=https://www.head-acoustics.de/downloads/eng/bhm_III/D1302_BHM_III_2_e.pdf]https://www.head-acoustic.../D1302_BHM_III_2_e.pdf[/link]

Jeff