Trackday noise limits

[QuattroFever]

just a quick thread to get some ideas on what people have got away with when doing the trackside noise tests.

I have a 3" pipe with one box at the rear thats cylindrical and about 6" diameter and 12" long.
It has a sport cat but would like to have that removed if i can get away with it.

im guessing it's quite a broad limit if a thundering tvr v8 can pass a 103db limit.

obviously alot of factors come into play here, if you can remember the weather and test conditions at the time as well post it up...

[Rusty]

Mine's 89dB and has a 3" turbo back with sports cat, dropping to 2.5" over the rear subframe and a single box. It's quiet TBH.

[s2driveruk]

cats off, 2 x 2.5in and a single small rear silencer...103db - epic noise test fail at Castle Combe last year
Cats on and it was about 92db IIRC

Really depends on the track and what noise limit they employ some have 105db, other have a strictly enforced 95db limit.

If in doubt get it checked at a track, CC will do this at no charge and I believe many others will but best to phone ahead.

[Jonnybravo]

My Peugeot was 106DB Static at brands with one silencer.

As mentioned its all down to where your going to take it, Bedford run a super strict 87db drive by that anything with a decent amount of boost you will get black flagged.

I know a lot of people who have spent a LOT of money trying to get the noise down on their cars, I have no idea how the Audis fair tbh, or atleast ones with a good amount of power as the type of system can have a massive effect on the power the engine makes in some cases.

[Ian Simmonds]

The RallyRep was 'over' 107db as a naturally Aspirated 10v 5 pot. And it was very loud… That was running a 3” Scorpion Single rear box Ur exhaust off the KV downpipe.

Now it’s got an AAN, with AAN downpipe Siamesed with a Ur downpipe, then exactly the same system….

And it’s so quiet I can’t disturb the neighbours if I try…

Like Rusty, I’d be surprised if it makes more than 90db now.

If you make 98db with that set-up I'd be utterly shocked.

[QuattroFever]

looking at it then i'll almost certainly be over if i remove the cat and "maybe" scrape through with it on.

Forget any tracks enforcing under 100db i guess.

Think im gonna need another box...and it sounds so good as it is.

[newsh]

My coupe is way over for Castle Combe, had to buy one of those horrible dB killer things to get it through.

Thats RS2EM, GT3071, full 3" turbo back, no cats and a single back box about thesize of a large bag of crisps with an additional small 6" dia Jetex box just before the rear axle..

[Jonnybravo]

looking at it then i'll almost certainly be over if i remove the cat and "maybe" scrape through with it on.

Forget any tracks enforcing under 100db i guess.

Think im gonna need another box...and it sounds so good as it is.

Bedford is 101, its the drive by thats a killer but most drive bys are well under 100 I believe.

I've heard good and bad things about these supertraps, I can't personally say they look like their going to do any good for engine power ! but I could easily be wrong about that.

[QuattroFever]

Bedford is 101, its the drive by thats a killer but most drive bys are well under 100 I believe.

I've heard good and bad things about these supertraps, I can't personally say they look like their going to do any good for engine power ! but I could easily be wrong about that.

How about one of those active exhaust vacuum solenoid/actuator thingys?
Have it on a boost line or a switch that flips a paddle in the exhaust reducing noise temporarily?

[Rusty]

Exhaust cutout - I did a thread on them a year or two ago. On a coupe, you could fit one under the rear seats and have a 3" side exit that screams away when you want Downside is additional weight.

[Robatron]

I have a 2.5" system, decatted with only the rear silencer left, I believe? Anyway, it was in the low 90s when I had the K&N filter but it's got quieter since then.

The TVR is way in excess of 100db but I've actually made it out and around Castle Combe in it.

[Dingo]

I've just got mine back on the road for the summer and measured it with an I phone, dont know how accurate they are but I got 88bd at 6k rpm at 1 meter away, I run a 3" turbo back (no cat) with milltek centre & rear and I think it sounds lurvvvvly but not too loud, did oulton park last year and I think it was 105db limit

[Rusty]

If you don't want to be restricted on which track days you can do, I'd suggest that 95dB would be the highest you'd want to go, I think most are 98dB and some are over 100. Very few are over 105 and you'll end up paying more for them as they're termed supercar days for those silly £££ cars that are ear-bleedingly loud.

[terrybullwon]

My Peugeot was 106DB Static at brands with one silencer.

As mentioned its all down to where your going to take it, Bedford run a super strict 87db drive by that anything with a decent amount of boost you will get black flagged.

I know a lot of people who have spent a LOT of money trying to get the noise down on their cars, I have no idea how the Audis fair tbh, or atleast ones with a good amount of power as the type of system can have a massive effect on the power the engine makes in some cases.

I think its fair to say the more power your car is making the louder the noises.

Any stockish S2 should pass no problem at all.