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View Full Version : Exhaust noise reduction - Trackday


chimp007_uk
21-10-10, 01:47 PM
I think my car is going to be pushing the 101db limit at Bedford on Monday... Sadly never got it there for a test prior :(

Car is an XE on carbs. Has individual filters fitted and an Ashley 2.25" 2 box exhaust fitted with standard manifold.

anyone got any tips I could try to help?
Sloth
21-10-10, 01:50 PM
demon tw@ts red catalogue. they have noise reducers chap
chimp007_uk
21-10-10, 01:54 PM
I've seen SuperTrapps etc, but I think I've left it too late to get anything order etc...

Was more thinking of the resonance at the tailpipe, as the boxes are not repackable :( was reading about 90degree downturns etc
Mike
21-10-10, 01:57 PM
I've seen SuperTrapps etc, but I think I've left it too late to get anything order etc...

Was more thinking of the resonance at the tailpipe, as the boxes are not repackable :( was reading about 90degree downturns etc

Demon tweeks deliver next day on all in stock items.
chimp007_uk
21-10-10, 02:20 PM
Just looked, £93 + postage!!! Having a giraffe... Any other options, looked on the bay
Stuart
21-10-10, 02:27 PM
U bend on the tail pipe...?
Ernie
21-10-10, 02:32 PM
Stuart your car is to Gay to make any noise i know as ive been out on track in it lol.
chimp007_uk
21-10-10, 02:55 PM
U bend on the tail pipe...?

was thinking that or a 90 degree, most the people on eBay won't let me collect though, think I left it too late.
SR-Rally
21-10-10, 03:30 PM
Weld a small bar in the exhaust tip inch or so from the end, don't know the inns and out of how it works but alot of my friends road rally cars do this and on most it makes big enough difference to pass noise. Which is 96 for us I think.
SR-Rally
21-10-10, 03:32 PM
This was about 100 befor the bar welded in and 96 through scrutiniering. So worked for this civic

http://i573.photobucket.com/albums/ss177/sr-rally/benphone294.jpg
Sloth
21-10-10, 03:38 PM
or weld a peice over half the tip in a D shape
Will F
21-10-10, 04:01 PM
or weld a peice over half the tip in a D shape

Not the best idea to be fair - thats like ramming half a bananna in there! lol
chimp007_uk
21-10-10, 04:09 PM
Errr thanks?

Was thinking about possibly a small bar inside to hold some wire wool in there.
SR-Rally
21-10-10, 04:18 PM
Errr thanks?

Was thinking about possibly a small bar inside to hold some wire wool in there.

how strict are they? As if you have wire wool in with rallying them make you pull it out and try again, might not be as strict as your on a track. I'd try the bar as few boys round here swear by it.
Southie
21-10-10, 04:20 PM
Maybe no good but how about something like this, its a common thing for bikers. CLICKY (http://cgi.ebay.co.uk/BAFFLE-DB-KILLER-SUIT-2-5-60mm-STRAIGHT-EXHAUST-CAN-/270608502457?pt=UK_Motorcycle_Parts&hash=item3f01860eb9) :)
Stuart
21-10-10, 04:45 PM
Given how evil Bedford are, they will be uber strict :(
chimp007_uk
21-10-10, 05:04 PM
I've read some reviews, and seen that they are really strict.

As for the bike can silencer, I did look at them. There's hundreds on ebay, but after reading reviews and email a couple of sellers, they said they wont work on a car?!
SR-Rally
21-10-10, 05:19 PM
Have you tested to actually see if car is to loud?
chimp007_uk
21-10-10, 05:22 PM
I had it on a sound meter I bought... Not sure if it's calibrated! It was 103db @ 3/4 rpm 50cm away @ 45deg.

My brother's car was tested today at 99db and that is certainly quieter than mine. Just need some tricks to drop the noise by a couple of db's to stand a chance.
Stuart
21-10-10, 05:34 PM
say its a tesla lol
SR-Rally
21-10-10, 05:35 PM
We wired rev counter onto a switch on my mates sunbeam as his is to loud, when he goes into scrutiniering he flicks it off so that they can't see what it's revving to, hasn't had problem with passing yet and done 3 rallys with it like that. He just revs it to what he knows will pass,
Stuart
21-10-10, 05:39 PM
iirc Bedford have driveby meters too :(
chimp007_uk
21-10-10, 05:39 PM
say its a tesla lol

heh??:wtf: :confused:
mowgli
21-10-10, 05:47 PM
electric car.......


chimp, if you want exhaust bends quick & fairly cheap, find your local truck spares place, the TTC parts book has a section of all sorts of bends etc....
Gareth_C
21-10-10, 06:04 PM
Im running a xe on tb's with no filters and a 2.5" straight through exhaust and I got my decibel reading from 103 to 96db by fitting a jetex decibel insert ther about £27 delivered iirc from demon tweeks. :thumb:
chimp007_uk
21-10-10, 06:47 PM
Im running a xe on tb's with no filters and a 2.5" straight through exhaust and I got my decibel reading from 103 to 96db by fitting a jetex decibel insert ther about £27 delivered iirc from demon tweeks. :thumb:

I looked at them earlier whilst I was at work, but they don't do a 2.25" version, only 2" and 2.5" :(
Ben
21-10-10, 06:51 PM
As said weld a bar across the hole this disrupts the sound path thus making it quieter!
chimp007_uk
21-10-10, 07:36 PM
Im running a xe on tb's with no filters and a 2.5" straight through exhaust and I got my decibel reading from 103 to 96db by fitting a jetex decibel insert ther about £27 delivered iirc from demon tweeks. :thumb:

Just looked and there £10.52 on demon thieves posted... But thats a 2" size, so would need to sleeve it. Jetex are only in Stratford upon Avon, so will give them a call in the morning and see if there's anything thet can make up or suggest, not to far to drive if need be :)