How to noise test car prior to track day

[James Junior]

Hi all,

My 370Z is fitted with HFCs and a cat back exhaust and is very loud.

I did a track day at Oulton end of last year and just scraped through the static noise test.

I want to book a days tuition at Bedford, but I am concerned in case I fail the noise test as this would mean a lot of time and money wasted.

I have some components on their way from the US to quieten the car down but they won't arrive for a while. Even when they do, it'll still be loud. I have checked with Cobra who manufacture my exhaust and they don't do bungs unfortunately.

Is there any sort of device anyone can recommend that can be used to do your own static noise test? I downloaded an app on my iphone but have read numerous comments that they are a waste of time.

Thanks in advance for any assistance you can provide.

[E-bmw]

Phone app definitely waste of time.

Ebay DB meter, reasonably accurate, but remember 3dB is DOUBLE the noise level, so even if it is fairly accurate it may be of no use.

Best way is to go to the track you intend to attend & ask them to test it, they will gladly do it & tell you if you would have passed, I have done it before myself.

[CrutyRammers]

The ebay sound meters are fine - mine gave exactly the same readings as the expensive VOSA one when I did my IVA test.
I'd heard of the phone ones not being much good, but a chap on locostbuilders recently did a back-to-back test with an ebay meter and they came out the same.

[Steve H]

If you only just got through the static test at Oulton I can't see it passing at Bedford, probably dicey even with the mods unless they are pretty drastic (and there are much better places to receive tuition anyway).

[QBee]

Are your tailpipes a nice cylindrical design, clean cut at the end of the pipe, or do they have rolled edges etc?
If clean cut straight tubes, then you can get bolt on additional silencers. We in the TVR fraternity use them for exactly this reason, and I have had to bolt them on at a number of tracks, as the sound test can vary substantially with air pressure, humidity, temperature etc. I have been as low as 97 at Cadwell Park, and as high as 107 at the same track, different day. Bedford is always a challenge for me.

You can see what they look like at: http://www.actproducts.co.uk/silencing/trackdays/

They do a variety of diameters. Mine are 2.5 inch if you want to try them

[Sigmamark7]

If you are anywhere near Castle Combe, they will test your car and if it fails, Merlin Motorsport are based there and have a range of additional silencers they will let you try in order to get the noise level down.

[QBee]

Having looked at your profile, you are in Manchester.

Phone Oulton Park, their direct number not the MSV booking line, and ask them when you can bring the car down for a noise test. They will be happy to help, especially if you can get there on the day of a track day, but any day they are open will do.

They can give you a proper test reading.

01829 760301 Is the direct number.