Silencer advice/ dimensions

[AV8]

Chuffmeister said:

Great visual. I've been toying with the idea of semi-sleeved. Does it get rid of the agricultural farting sound? Also, we're the original perforated pipes welded in or just held in by the larger OD pipe at each end?

Cheers
Chuffy

I think in a lot of cases the agricultural sound is caused by not putting the wadding back in. Certainly in the case of dealers who used to offer the "sports exhaust" as an after martket, the box was fully sleeved and the wadding removed.
IIRC the pipes were just pushed in to the sleeves.
I bought a length of 2 1/4 " perf before I started but because mine were so good I didn't use it. I remember a thread on here years ago about a guy who did similar and when he opened the box the pipes were rotten.

[Chuffmeister]

Thanks!

[Chuffmeister]

Just an update. I removed the exhaust again today whilst the car is on stands (doing the sump). Looking at it in more depth, it certainly seems as if the Austec 'sports' version was done by cutting and re-welding the end of the silencer. I decided to go in by the same route. Basically their were two flared steel sleeves that had simply been pressed onto the exhaust entering the silencer at the other end and then held in place once the end of the silencer had been welded back on. The pics speak for themselves.

I've also done a rough sketch for anybody wanting the dimensions of the silencer and photos on the internal pipes etc. I'm sure so somebody will find it useful..

Cheers
Chuffy

[Chuffmeister]

Perf and glass all in now. Packed in tight. 51mm perf a perfect fit. Off to the welders on Monday!

[QBee]

Let's hope you are "chuffed" with the resulting sound

[Chuffmeister]

QBee said:

Let's hope you are "chuffed" with the resulting sound

That's bad! What is louder... Precats and main cat in with sleeved silencer, or no cats and standard silencer? I want it a quieter, but not silent! I just want to get rid of the agricultural farting sound, but still want it to sound great under load. I was considering using the old sleeves and wrapping them around part of the length of the perforated pipe to make it semi-sleeved. Just not sure on volume, whether semi sleeved will be too loud?

[QBee]

Get the decibel 10th iPhone app and measure the noise level at 4500 rpm from half a metre above and out from the tail pipes, when you have it all back together.
I will test mine tomorrow. Mine is cats out, standard silencer, which is around or just over 105 dB(A) according to MSV race tracks.
Then we can compare.
I would think cats in, sleeved will be louder.

[Chuffmeister]

QBee said:

Get the decibel 10th iPhone app and measure the noise level at 4500 rpm from half a metre above and out from the tail pipes, when you have it all back together.
I will test mine tomorrow. Mine is cats out, standard silencer, which is around or just over 105 dB(A) according to MSV race tracks.
Then we can compare.
I would think cats in, sleeved will be louder.

Can't do it Anthony... No iPhone and exhaust in pieces off car awaiting welder. Perhaps somebody else will have a result with cats in and sleeved?

[AV8]

Chuffmeister said:

That's bad! What is louder... Precats and main cat in with sleeved silencer, or no cats and standard silencer? I want it a quieter, but not silent! I just want to get rid of the agricultural farting sound, but still want it to sound great under load. I was considering using the old sleeves and wrapping them around part of the length of the perforated pipe to make it semi-sleeved. Just not sure on volume, whether semi sleeved will be too loud?

Mines semi sleeved as you can see from my earlier post with the pics to proove. I still have all the cats in and mines a standard 400.
I would describe it as a bit louder than standard but with a nicer note. It has a more sporty tone to it with less of the "woolly" sound of the standard system. It also pops and crackles more than when standard and definitely sounds more sporty under load.