Stainless steel exhaust; quieter or louder with age?

Stainless steel exhaust; quieter or louder with age?

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Codswallop

Original Poster:

5,253 posts

201 months

Friday 13th September
quotequote all
I've got a 2005 BMW E46 330ci that had the rear exhaust rust away. Understandable given the age. Exhaust has been welded previously but was beyond saving. BMW UK didn't have any OE replacements available.

New rear silencer fitted (scorpion back box), rest of the system standard.

It's awful loud with lots of drone now. Somehow, it's louder than the old exhaust which had a hole in it!

Will the new exhaust get quieter or louder over the next few weeks?

What are people's experiences. Internet is not agreeing on what to expect.

brillomaster

1,396 posts

177 months

Friday 13th September
quotequote all
it'll get quieter as the inside cokes up - it'll sound less tinny/raspy as well as the carbon deposits act as sound deadening and insulation.

that said, its entirely possible that the design of the new backbox is louder than the existing one, even with a hole in. standard silencers will be very muted with various expansions chambers and baffles to cut drone and certain frequencies - a sports exhaust will be more concerned with throughflow of gases and wont have such importance in the design as sound suppression.

DaveCWK

2,099 posts

181 months

Friday 13th September
quotequote all
They do get quieter but it's not a significant change, especially if its a straight through design.
Personally I prefer the deeper exhaust sound you get from thicker mild steel exhausts over stainless.

Den Den

272 posts

26 months

Friday 13th September
quotequote all
I had a stainless system fitted to one of my old Saab 900's when the original fell to bits, but wound up changing back to a mild steel setup after a while. The stainless one resonated like buggery, especially when cruising at motorway speeds.

Ultrafunkula

998 posts

112 months

Friday 13th September
quotequote all
I'd check that the new exhaust has a resonator/expansion box on it. Cat back sports exhaust can either be with or without, without means drone sometimes.

Vizsla

1,053 posts

131 months

Friday 13th September
quotequote all
Codswallop said:
I've got a 2005 BMW E46 330ci that had the rear exhaust rust away. Understandable given the age. Exhaust has been welded previously but was beyond saving. BMW UK didn't have any OE replacements available.

New rear silencer fitted (scorpion back box), rest of the system standard.

It's awful loud with lots of drone now. Somehow, it's louder than the old exhaust which had a hole in it!

Will the new exhaust get quieter or louder over the next few weeks?

What are people's experiences. Internet is not agreeing on what to expect.
Thanks for the heads-up, I have a 2001 E46 330ci, had it from new and it's still on its complete original exhaust system at 150K miles. I would say under acceleration it was a little bit growly when new, noticeably quieter now after 23 years!

stevieturbo

17,523 posts

254 months

Friday 13th September
quotequote all
Codswallop said:
I've got a 2005 BMW E46 330ci that had the rear exhaust rust away. Understandable given the age. Exhaust has been welded previously but was beyond saving. BMW UK didn't have any OE replacements available.

New rear silencer fitted (scorpion back box), rest of the system standard.

It's awful loud with lots of drone now. Somehow, it's louder than the old exhaust which had a hole in it!

Will the new exhaust get quieter or louder over the next few weeks?

What are people's experiences. Internet is not agreeing on what to expect.
If you want a standard exhaust, buy a standard exhaust. There seem to be no lack of them available.

Although it would seem odd that just the rear silencer is making that drastic a difference. Although the E46 is quite a huge rear silencer ?

more than likely it will only get louder with whatever packing material is in it burns away over time, but unlikely a few weeks.

paintman

7,765 posts

197 months

Saturday 14th September
quotequote all
Fitted a full sports stainless steel system incl tubular manifolds to my 3.5 Range Rover Classic some 25+ years ago.

It hasn't got any quieter & on long motorway journeys it's becoming a bit of an irritation - perhaps I'm just turning into Victor Meldrew.

stevieturbo

17,523 posts

254 months

Saturday 14th September
quotequote all
paintman said:
Fitted a full sports stainless steel system incl tubular manifolds to my 3.5 Range Rover Classic some 25+ years ago.

It hasn't got any quieter & on long motorway journeys it's becoming a bit of an irritation - perhaps I'm just turning into Victor Meldrew.
Ultimately if it's your daily....just leave it std !

If it's a toy, then do silly things.

Still find it hard to believe a rear silencer only could make such a huge difference. Scorpion certainly aren't one of the best makes, but equally not the worst.

Codswallop

Original Poster:

5,253 posts

201 months

Saturday 14th September
quotequote all
Thanks for the feedback guys.

Mixed bag of experiences again, so clearly there isn't one right answer if it'll quieten down or not.

I'll leave it on and see how things go over the next few weeks. Car is a weekend toy, but I do not want it to sound anti social.

The OEM BMW exhaust it one piece from cat back and costs almost £3k! None available in the UK either, hence why I went aftermarket and just got a back box.

I honestly did not expect a back box to make such a huge difference to sound levels. If it doesn't get quieter I'll get a mild steel back box from Autodoc or similar.

E-bmw

9,969 posts

159 months

Saturday 14th September
quotequote all
TBH having had several stainless exhausts over the years, it is more a case of the purpose of what you have bought rather than it being stainless.

You have bought a "performance" exhaust, as more sound makes ANY car go faster it now makes more noise. wink

Having said that it MIGHT get a BIT quieter, but you would likely need sensitive measuring equipment to detect a difference.