Getting Louder

[graeme_laslett]

Hi All,

 

Back in Jan I fitted a Hurricane Induction kit and 52mm TB. In March, off I went to my local airfield for a track day and was noise tested at 92 db. Same airfeild, same organisers in May and 94db, Oulton Park (different organisers) in June which messured at 95 db. August, back at the airfield with the original orgainsers and 97db.

 

Yesterday, back at the airfield I was messured at 98db, which is the allowed limit.

 

Has anyone else had the same experiance? A couple of db here and there I can cope with, but the car is progressivly getting louder and next time I may not be allowed on track.

 

The only modifitations done this year has been a new ARB and upgraded the toe links.

 

Any thoughts on what could be causing the increase in noise?

 

Many thanks

 

G

[TheRon]

What silencer do you have? How old is it? They can become less effective over time.

[graeme_laslett]

I beleive it is a Janspeed silencer. Fitted before I got the car and the reciept (from PTP) just says S1 Silencer, fitted in June 2005

 

Could this really be the cause?

[chris_h]

Yep agree with Tim, your probably losing the insides of the silencer. (or the honeymoon in the cat)

[Steve J]

Do you mean honeycomb there Chris?

[graeme_laslett]

Thanks guys

 

Had a quick look at the exhaust system and it seems that the manifold and cat are originals (1999 car) and a silencer with no distinguishing marks added in 2005.

 

I need a winter DIY project so will probably look at replacing the lot - any suggestions bearing in mind my local airfield has a strict 98db limit?

 

G

[Martin R]

If you are going to do trackdays there is a lot to be said for a standard exhaust. If it were me as a winter DIY, i would drop the exhaust manifold off and remove all the weld off the inside of the manifold where it joins the head. Check the cat is ok, they are pretty robust. Have a look in the end and make sure the honeymoon is intact Then put a standard exhaust on. What you lose with a standard exhaust you will gain from removing the excess weld HTH

[chris_h]

Do you mean honeycomb there Chris?

 

 

lol I typed it on my android phone and the stupid thing is always changing words grrr !!! Hate technology that thinks it knows better than the human

[graeme_laslett]

If you are going to do trackdays there is a lot to be said for a standard exhaust. If it were me as a winter DIY, i would drop the exhaust manifold off and remove all the weld off the inside of the manifold where it joins the head. Check the cat is ok, they are pretty robust. Have a look in the end and make sure the honeymoon is intact Then put a standard exhaust on. What you lose with a standard exhaust you will gain from removing the excess weld HTH

 

Martin

 

That is a great idea - many thanks. It might even get me down to the 88db needed for Croft.

 

The "Excess Weld", is that as simple as a metal file and smooth it down? I've never taken the exhaust manifold off so this is going to be a learning curve for me.

 

I knew Elise ownership would be different, but....... taking the cat on honeymoon!!!!!!!!

 

G

[Martin R]

The roughest round file you can find should do it. I used a small air grinder i had use of at the time. I would leave a small amount of the weld otherwise you will have to weld around the outside of the manifold HTH