105db to 98db silencer methods

[RyanW]

Anyone got any suggestions or experience on how to get my 105db car down for a 98db track day ive mistakenly booked?
Ive been looking at combining one of these with some Silencer Packing:


but none of the manufactures quote any expected results, any one have any experience or suggestions?

[tankplanker]

What car is it? Can you repack the silencer?

[Steve H]

Assuming you are talking about static tests for both 105 to 98 is a big ask. Isn't it double the volume for every 3db? If so you need to half the noise, twice .


Car details might help but I wouldn't count on getting it done.

[CrutyRammers]

That's a real big job. The only way I've managed that is with a wodge of wire wool up the spout, and that won't last long enough. First check your silencer packing and redo with acoustafil if it needs it. I've tried all sorts of bungs and things in mine and the best results have been with decibel devils, which took 3db off. what sort of car is it?

[F355GTS]

RyanW said:

Anyone got any suggestions or experience on how to get my 105db car down for a 98db track day ive mistakenly booked?
Ive been looking at combining one of these with some Silencer Packing:


but none of the manufactures quote any expected results, any one have any experience or suggestions?

I fitted something similar some years back to a 200bhp Caterham, it cut the power by at least 25% and I suspect did the engine no good

[RyanW]

Thanks for the comments, for reference the car is a Civic EP3 cup car. Think I will go and have a new system made up..

[Hol]

Does it have a long decat pipe, that you could weld a bullet silencer into a spare decat pipe.

[SlimJim16v]

You can get a silencer that clamps on to your tailpipe. Not sure who makes em, but seen them on cars at track days.

Found em http://www.demon-tweeks.co.uk/motorsport/universal...

[HustleRussell]

We had to lose 4dB from a racing Lotus Elan, we managed to do so with an additional silencer and a decibel insert but lost about 40% of the car's power in the process.

[RyanW]

HustleRussell said:

We had to lose 4dB from a racing Lotus Elan, we managed to do so with an additional silencer and a decibel insert but lost about 40% of the car's power in the process.

Didn't realise the silencers suck so much power. thanks

[HustleRussell]

RyanW said:

Didn't realise the silencers suck so much power. thanks

The additional silencer probably wasn't so damaging to the power, these again it only got us down to 102dB. It was the insert which killed it (the noise and the power).

If you don't want to lose significant amounts of power a new system is probably in order with a big silencer or two. Or book noisy test days like we do nowadays!

[GreigM]

If you are getting a new system built could you make it a twin exit? With each exit pointing away from each other - that should help considerably.

[227bhp]

RyanW said:

HustleRussell said:

We had to lose 4dB from a racing Lotus Elan, we managed to do so with an additional silencer and a decibel insert but lost about 40% of the car's power in the process.

Didn't realise the silencers suck so much power. thanks

They don't.
Getting one or two more straight through silencers welded in is the best way to do it.

If you look at one of those things from a different view you can see why they reduce power:
http://www.demon-tweeks.co.uk/motorsport/universal...

Edited by 227bhp on Thursday 30th June 22:45

[4.7]

My Cerb can go from twin straight through pipes to four large bore silencers that still stop a fair way before the end of the car (which really helps - static and drive by). 2 silencers 103db and 4 is 98db ish. The large diameter keeps the power loss acceptable.

[greenamex2]

Decibel inserts are horrific for reducing power/revs. My race Corolla was limited down from 9000RPM to 7000RPM when I fitted one. Could probably get some of that back with remapping but not much.

[QBee]

Suggestions:

1. Call the track day organisers and plead ignorance/blindness/stupidity/keenness to do one of their track days. Many are reasonable and will let you transfer to a more suitable day. After all, they want you to keep coming on their days.....
2. Get the car tested so you know what it actually reads - most track day organisers will do this on a day they have an event running.
3. See if you can get a friend to take your booking, and book a different day for yourself.
4. Get some of these, but be very sure of the size of your tail pipes first - they will only fit straight pipes:

http://www.actproducts.co.uk/product-category/trac...