[MadScientist1337]

Hi guys, newcomer to the forum here, looking at starting some work on my F97 X3M Competition.

I was just wondering, does anyone have any experience with either or both of these downpipes (catless version) ?

Evolution Racewerks
https://www.rgsportshop.com/index.ph...roduct_id=1394

Project Gamma
https://shopprojectgamma.com/collect...42998849143003

I'm trying to put together a really drama-filled loud and abusive exhaust, going to be going catless all the way through (Evolution Racewerks midpipe and Remus axleback as well as the DPs)

So I'm just trying to figure out which would be louder, as on their website Project Gamma claim their downpipes are 4" whereas the Evolution ones are 3". I know from a performance perspective 3" -> 4" is negligible, but I've read in a couple places that 4" is a notable increase in volume and turbo noise relative to 3". I'm just wondering how much validity is in that statement or if the Project Gammas are even 4" at all.

I've seen some people in here saying things like "its too loud" so hopefully me looking for EVEN LOUDER won't be met with too much scorn

Thanks in advance for any input

[MadScientist1337]

Just checking in on this again in the hopes that someone can provide guidance between these 2 downpipe options for superior exhaust noise potential.

Any input is much appreciated, thanks!

[MadScientist1337]

Originally Posted by alan435

If you want to maximize the volume, going 4" would be the better option. The downside is making sure the fitment is right and getting an exhaust to fit up to the downpipes since most are made to fit up to stock. you'll also lose some low-end torque, but it should make up for it higher in the powerband.

Thanks for the response, I will go for the Project Gammas then!

I think the fitment will be fine, I was thinking to get RG's Evolution Racewerks Midpipe and then an axleback... Probably Remus. Though I'll have to do some research on which exhaust would match the maximum-attack aggression of the 4" downpipes the best. Either ER midpipe + Remus axleback, or a full remus from downpipes back. Not sure what will be best yet.

[mike@x-ph.com]

Evolution Racewerks are handbuilt in the US; their finish quality is second to none
you won't see a difference in power between the 2 brands

[Info@mad-us.com]

Op,

Have you checked out our 4'' Downpipe? It has a factory fit meaning it will fit any mid pipe you want to pair it with.

https://mad-us.com/mad-bmw-x3m-x4m-s...f98-downpipes/

When it comes to sound the larger diameter will be slightly deeper sound not necessarily louder or at least anything noticeable. Adding a mid pipe or rear muffler will help with the loudness.

[Eddie.gomezzz]

I installed PG downpipes on my x3m amazing quality and craftsmanship make sure to get it coated with the ceramic coating! Had them installed at 14k currently at 36k