Noise Testing....Is too loud obviously too loud?

[G-Lader]

I'm going to be starting trackdays soon, I'll be going to one before I actually book one so that I can get a noise test done and not waste any money, but I'm curious about the noise limits.

My car is a Polo G40 with a 4-2-1 manifold and and then a 3" pipe with one box on it. It's quite loud especially with the charger but I put most of that down to the lack of soundproofing.

If a car is too loud is that likely to be obvious prior to the test? I've got no idea what say 98db sounds like, but would I have no doubt what so ever if I heard something louder? Do many cars fail the tests? What sort of cars are they? Having been passed by a Gallardo yesterday on the motorway I can't believe that my car is louder than that and surely a stock Lambo doesn't fail the scrutineering?

I know this is largely academic because I'm going for the test anyway, but I'm interested all the same..

[Walton]

Can't really do it from 'guesswork', though I think any car with an after-market system would struggle to meet 98db static.

For noise legislation reasons, a lot of stock high performance cars feature exhaust valve that only open at high rpm, hence they can get around noise testing at say 4500rpm, but are very loud once on track.

There's a free iphone app called 'Decibel' that'll give you a rough idea of levels (assuming you know someone with an iphone). 50cm from exhaust at 45degree angle - 4500rpm should do it.

Cheers

Rich

[jon-]

Walton said:

For noise legislation reasons, a lot of stock high performance cars feature exhaust valve that only open at high rpm, hence they can get around noise testing at say 4500rpm, but are very loud once on track.

and even then such exhaust systems are becoming more and more pointless as noise meters go up around the tracks

[Wh00sher]

Walton said:

though I think any car with an after-market system would struggle to meet 98db static.

I totally disagree with that. 98db is LOUD. My track car has an `aftermarket` exhaust, no soundproofing and seems loud inside. Its only 88bB Static.

OP, if you are near a circuit, give them a ring and pop over, from my experience, they`ll happily do you a noise test.

Edited by Wh00sher on Tuesday 28th September 20:43

[schuey]

If it helps,my G40 with very similar exhaust set up easily passed a noise test! G-lader noise is like no other!

[G-Lader]

schuey said:

If it helps,my G40 with very similar exhaust set up easily passed a noise test! G-lader noise is like no other!

Nice one, did they tell you how many db you did?

[git-r]

Lol some 'interesting' advice here!

98 db's isn't loud for a static noise test. Bedford is the strictest track I know and they use this limt. Yes the only way to check is to test it although at bedford you can pass the static then fail the drive by. Also you can pass one day then fail the next and once you've tripped the meter it's game over. No refund... This is only really a problem if you are close to the limit but their testing is so inconsistent it can still be a lottery.

Most other trackdays are much better tho and have a 105db limit which is much much louder..

[HVAC MATT]

If it helps a Focus ST with a full system and a sports car comes in around 98DB was quite miffed when I went to Snettaton and didnt get over 100 DB. Same car also passed at Brands hatch indy.