Exhaust question

[muhuha]

Hopefully someone can help with my technical question, i'm putting an extra silencer (12" straight through baffle type) in my exhaust system it's 2.5" which is the same as my current exhaust. my current exhaust system goes Turbo>elbow>downpipe>(then straight exhaust where i could put the silencer)>centre box>(more pipework where i could put the silencer>directly into my backbox.

I'd say the location closer to the engine i would reduce more noise but the location near the backbox would be an easier location.
Can't see the gas flow being effected because the standard exhaust is 1.75" and current is 2.5".

Cheers

[SWR Performance]

muhuha said:

Hopefully someone can help with my technical question, i'm putting an extra silencer (12" straight through baffle type) in my exhaust system it's 2.5" which is the same as my current exhaust. my current exhaust system goes Turbo>elbow>downpipe>(then straight exhaust where i could put the silencer)>centre box>(more pipework where i could put the silencer>directly into my backbox.

I'd say the location closer to the engine i would reduce more noise but the location near the backbox would be an easier location.
Can't see the gas flow being effected because the standard exhaust is 1.75" and current is 2.5".

Cheers

I'd place it at the rear... less heat and it will survive longer.

[stevieturbo]

And it will silence more at the rear

[HowlerMonkey]

Leaving a long length of pipe with no muffling will usually yield a non-enjoyable exhaust note that has some pretty sharp resonance peaks.

Having the muffler near the end allows it to act on both the engine noise and the pipe resonance.

If your "front position" is closer to the middle of the car, you might not have any issues with bad pipe sound.

My 280zx turbo sounded best with a high flow catalytic convertor at the midway point and nothing else but pipe out the back but my 300zx sounded best with a large two chamber muffler at the rear.

[Nick1point9]

SWR Performance said:

I'd place it at the rear... less heat and it will survive longer.

Generally speaking, the exhaust components that stay hot last longer (ignoring manifolds cracking due to stress/vibration and cat internal failures) as the heat prevents water vapour condensing and stops the box from corroding as quickly. That's why back boxes rot away first but manifolds and downpipes rarely rot away.

[SWR Performance]

Nick1point9 said:

Generally speaking, the exhaust components that stay hot last longer (ignoring manifolds cracking due to stress/vibration and cat internal failures) as the heat prevents water vapour condensing and stops the box from corroding as quickly. That's why back boxes rot away first but manifolds and downpipes rarely rot away.

I know, I was thinking about excessive heat frying the packing material if it's not an all-metal damper...

And, if you have a big drone of sound in the car on overrun with a big diameter straight pipe, make an X-shape from two small strips of sheetmetal and insert it into the pipe section, and spotweld into place. Drone gone...

[HowlerMonkey]

I remember running bullet mufflers on mazdas that were stainless steel wool packed instead of fiberglass.

They were mostly for use on the uncollected primary pipes in a "long primary" but I'm not sure they were made in a diameter to act on the entire exhaust of a car.