Trackday noise limits

[ashley]

General question...I'm just spec'ing up an exhaust for my turbo build, and it needs to be able to pass most track day noise limits.

Anyone have a view on what upper limit I should be specifying? I'm thinking ~98db, but really not sure...

Cheers

[pistol pete]

yeah i defo wouldn't go above 98..
its the drive by limit you have to watch too..

if you can aim lower i really woudl..
i was 95 at idle and was breaking the limit on drive by at croft

[Race Idiot]

Just get a legalis R, it seems that the noise measurements vary from track to track.

Currently I have a trust pex with no cat, which is pretty quiet for a tubby.

At castle combe it got 89db and then at brands hatch it got 98db
Only difference on the car was a different turbo, but still internaly gated no screamer pipe etc. So im not sure how much difference that would've made if any.

[ashley]

Thanks for the input guys, I'll see what PTR say when we discuss my plans in detail...I don't want a stoopidly loud exhaust, but equally I don't want it to restrict the power I make. It feels like maybe 95db is the top end I should be looking at, should get me on most UK tracks...maybe even have a removable bung for when I can't sneak past noise restrictions

[Race Idiot]

Thanks for the input guys, I'll see what PTR say when we discuss my plans in detail...I don't want a stoopidly loud exhaust, but equally I don't want it to restrict the power I make. It feels like maybe 95db is the top end I should be looking at, should get me on most UK tracks...maybe even have a removable bung for when I can't sneak past noise restrictions

I'm pretty sure the guy with the now deceased white PP democar used a legalis r on it and was making silly power. Although it probably would be better with a larger diameter custom made flexi.

[ashley]

Cheers...just not what I'm looking for style/ weight wise though

[GeorgeL]

Got to agree with the guys and what you are going for ash, 95-98 area will see you ok.

I know the guy who makes the exhausts for SVM to run on their GTRs and that's what he was specced to make.

Don't do what I did and turn up at Totb where the absolute max is 106 at 3/4 rev range. Then bargain for them to measure at 4.5k (Nowhere near 3/4) and then hit 119dB

Safe to say I'll be changing my plans for next time as it took some
Messing with the map and timing to get the car to quieten down for the static test. That's something I can't be bothered doing again.

Looking forward to seeing what you end up with end product

[Marmalade]

I have an unknown exhaust on my car which makes 100db static, but I a fine at Bedford which is one of the tougher noise regulated tracks in the UK.

Bedford is 101db static and 87db driveby.

So, if your aiming for 98db should be fine

[pistol pete]

You say tht I found croft tougher..
I am fine at Bedford.. Got told off at Croft. They were walking round with noise meters.. Stopping everything for a while etc..

[Marmalade]

You say tht I found croft tougher..
I am fine at Bedford.. Got told off at Croft. They were walking round with noise meters.. Stopping everything for a while etc..

Interesting, I did not realise that, good to know, thanks