Reduce noise for track day

[JSS 911]

I recently tried a track day at Goodwood but was black flagged for noise. The car is a Porsche Turbo fitted with an after market system ,static test at 4700rpm 103db, 105bd day, on track drive past is 101db and my worst pass was 107db . I tried to lift of past the mics but still fell foul of the little blighters and finally it was all over .So I have been looking for something to help me out and found these. has anyone any experience of these or similar

[QBee]

I use something similar on my TVR, but pointing backwards. Loses about 4 decibels and also softens the tone of the sound.

Your problem may also be that you have all that induction noise as well, coming from the same place. I failed the 103dB static test at Bedford last year (101 limit), but was allowed on because the Porsche GT3 RS behind me also failed at 103. We neither of us tripped the 87.5 dB drive by all day. So clearly the Goodwood drive by test is a lot closer to the cars than the Bedford one.

[KaneDB]

What is the outer diameter of your exhaust tips? I have some bolt on silencers with 3" ID that I don't use anymore that you're welcome to try, I'm pretty local to you.

[JSS 911]

KaneDB said:

What is the outer diameter of your exhaust tips? I have some bolt on silencers with 3" ID that I don't use anymore that you're welcome to try, I'm pretty local to you.

Kane, Thanks very much, might be worth a try. My pipes are 2.5" but I could get an a sleeve made up to try .

[QBee]

My TVR ones are 2.5 inch. They come from a company called ACT.
They are in East Grinstead.
Might be worth giving them a call, see if they will let you toddle over in the Porshe, try some and do a noise test.
I am quite sure they would be interested in the Porsche market.

http://www.actproducts.co.uk/silencing/trackdays/