[mp411]

Hi all. just wondering what yall would recommend for exhaust options for the 535i. Let me know what type you have and if you like the noise. Will an exhaust upgrade give me more hp?

Thanks

[bake]

Originally Posted by mp411

Hi all. just wondering what yall would recommend for exhaust options for the 535i. Let me know what type you have and if you like the noise. Will an exhaust upgrade give me more hp?

Thanks

Don't do it if you are looking for more HP, cause any gains are minimal. I have the BMW M Performance mufflers. I would classify the sound upgrade as mild, but I like them a lot. They are pricey though and the outlets remain single pipe on each side (I added quad tips on mine). Many other members have opted for M5 mufflers, but you would need to also fit your car with the M5 diffuser (assuming you have an MSport rear bumper)

[valbmw]

To get more power you need first to upgrade your exhaust system with catless downpipes or get it along with performance or sport version of the existing aftermarket products (Eisenmann, Supersprint, FI, Hamann, Meisterschaft etc.). This way you will add some power, sound and aestetics.

Another option is just upgrading the mufflers, no cats removal. The simplest way here is indeed taking the M5 mufflers with quad tips and adding a proper 5-series quad diffuser. In that case you get a bit sound and cool look. To avoid messing up with tips centering, take mufflers only, no axle back pipes because the M5 has a different angle of ones compared to the 5-series.

[TShoot]

Does having "catless" downpipes void any kind of warranty you may have with the dealer? Or, for that matter, does anybody in a state that does emissions check know if that will make you automatically fail?

I live in Maryland and they pretty strict. Probably not so much as California, but still a pain in the arse.

[valbmw]

Originally Posted by TShoot

Does having "catless" downpipes void any kind of warranty you may have with the dealer? Or, for that matter, does anybody in a state that does emissions check know if that will make you automatically fail?

I live in Maryland and they pretty strict. Probably not so much as California, but still a pain in the arse.

This turned to be a very interesting question There is always a walk around, otherwise a widest range of high-flow catted DP's and also the catless DP's would be flagged as illegal by e.g. DOT administration and wouldn't be openly sold everywhere.

I found it is very case-to-case thing, depending on state regulations for emissions, technical level of a testing authority and actually did the vendor get DOT Approval for its product or not. In each particular case it may go this way or that way, but this is the price of having your car's bigger output.

You may want to read this thread (for example, see the post #15): http://www.e90post.com/forums/showthread.php?t=252086

My friend in NYC was stopped by a cop because of noise and got a ticket for something like illegal modification not for street use. He didn't worry about it, went to his exhaust shop and got a letter that his exhaust is approved. Then judge cancelled the ticket.