Useless Factory V8 Muffler (Revisited)

[2003 V8 TT]

Johan - I recall some time back that you had posted a photo of an '03 Esprit's center exhaust muffler, depicting the "useless" nature of the tin can close-cell muffler. I think you said it was a buddy of yours who had an annoying rattle inside the muffler that prompted the dissection. Nonetheless, the photos is famous, and it most certainly became one of the "best held secrets" to ever grace the Esprit. (See attached photo.)

I'm writing because my '03 muffler is doing the same (damn) thing. After diagnosis by the dealer, it's neither the cats nor the internal straight exhaust pipes (any loose item in the pipe would have cleared itself during operation), and most certainly not the exhaust tips. After some investigation, a light tap with the finger on the muffler itself yielded the rattle. Knocking on the muffler a few more times, and you can hear something loose or dislodged in there -- trapped inside the close-cell muffler. My question to you is this: Upon opening the '03 muffler, what exactly did you guys find inside it? Was it a loose weld piece that broke off in the muffler? Or was it something that was still attached but loose, and tapping against the inside of the muffler causing the rattle?

Johan/All - My predicament: I'm contemplating the idea of drilling a 3"-hole (via circular saw) at the bottom of the muffler (dead center, at its lowest point), so that whatever it is will just fall out. But if the item inside is not sitting at the bottom of the muffler, but rather hanging loosely off one of the internal weld joints, I just perforated my muffler for nothing. If the item(s) do fall out, then I don't mind the hole being there, because the exhaust does not circulate through the muffler, and that any water or debris that gets in there, will fall right out of the same 3" hole. I don't believe internal rust will be a problem, since the inside of the muffler is of the same material as the outside, and no water would ever collect in there.

This is the cheapest way to go as far as getting rid of the rattling (I think). Plus I would like to keep the stock center exhaust for its exhaust note. But my other option is to go with after-market center exhaust straight pipes, which is quite a bit more costly than a 3" circular saw fix.

[airbusdrvr]

Don't drill anything!!! You most likely just have a crack in one of the pipes exiting the collector/fake muffler. Take it off and get it welded or get rid of the damn thing and put on straight pipes or a center exit exhaust system. You can buy the cheese grate valance ( for center exit exhaust ) from Viking Motorsport for about $80. Much cheaper than the one with holes. Then either buy the pipe from Viking or take it to Midas and have them make something up. Just make sure you attach a center support thing.

OOPS looks like you already have center exit exhaust. Just get rid of the fake muffler.

[Rob]

i'd suggest straight pipes too. just ditch the factory muffler and get some straight pipes on there - saves weight.

[Guest Troy Halliday]

If I remeber corectly the fake box was used because without it the V8 had quite a lot of lift at the back end. I will confirm this later. But perhaps a solution would be to but in some sort of belly pan/difuser instead.

[Rob]

If I remeber corectly the fake box was used because without it the V8 had quite a lot of lift at the back end. I will confirm this later.

Yes, I think thats right, in fact the lower valence (wing) under the bumper on the earlier v8's is designed to work in sync with the aero of the silencer box. Possibly also for homologation purposes the only way to go to effectively "straight pipes" for usa centre exit cars without needing to re-do the crash tests was a dummy box.

I ran my v8 at 170ish both with and without the rear box - didn't notice any difference. The centre exit cars obviously have a different valence...

[th4neuk]

I Dunno.

I really prefer the sound of mine with the centre exit over the straight pipes. The centre exit has a balance bar and this slightly changes the pulses of the exhaust note and IMHO make it sound alot better and V8 like.

Just my 2p but I prefer it.

I had heard that the fake box was only put on for the American Market as the car had to be seen to have a muffler as they call it even if it did nothing?? Not sure how true that is??

I'd go for the hole though. If you took the exhaust off and did it at the top you could have someone weld a piece back over the top and no one would know??

Just an idea?? They are fairly straight forward to take off.

Cheers

[2003 V8 TT]

Very useful feedback, guys! Thanks!

[Günter]

Whow! cant believe this is real, Lotus offers this as a muffler? Even in the US with its strickt regulations for imported cars?! If i wouldnt see it , i would think your kiddin me...