Hi all,

I am new to this forum. Kindly help...

I have a question about stock muffler vs aftermarket replacement vs straight-thru replacement. I have a 2004 530i.

1) Is there really a big, obvious difference in power/performance with a straight-thru muffler compares to stock muffler?

2) I heard straight-thru mufflers increase the HP for 3-5%, is that really true and can the increase of HP be felt?

3) And is there any difference between a stock muffler vs any universal muffler replacement (non straight- thru)?

Thanks all in advance...

 

 

Hi RemusExhaustShop,

Thanks for your fast response...

In response to your answer of 1) and 2), if the difference cannot be felt, why would many people want to upgrade?

And for 3), I understand upgrading to get a better look, weight and sound, but performance? since you state there is no big difference in performance in 1) and 2).

Just curious... Sorry for being stupid .

Thanks!

 

It is mainly a question of sound.
A certain group of owners would say the stock exhaust is somewhat too quiet and would like a little more grunt, with the added performance.
As for point 3, for example, on the 545i we dyno'ed a 9hp gain, which in itself cannot be overlooked, but it is not a dramatic performance increase.
I would say it highly depends on your application, some car models can really benefit from a straight through aftermarket muffler as the original setup is too restrictive.

In your case, the E60 5 series original system is somewhat heavy(2 silencers) and replacing with an aftermarket muffler will release trapped hp/tq.

 

Thanks again for your patient answering my questions...

I guess even replacing my somewhat heavy stock muffler, I would not really feel the difference in hp/tq as it is not obvious as you stated in 1) and 2).

Very much appreciated!