[Freemorfeem]

Hi, y'all, first post here! I've been really grateful for the community here so far!

I just got a 2010 335i 6MT RWD m-sport. I want to go FBO and tuned. It came with dual cone intake and a charge pipe with BOV.

After plugs, coils, and injector cleaning, I'm thinking next is exhaust and FMIC.

My knowledge is pretty basic, so I am wondering... full exhaust system or electric cutout? While I will do the FMIC myself, exhaust will be done by professionals.

Any thoughts or cautions, or pros and cons insights?

My goal is performance. And in terms of sound, a little deeper and more aggressive would be cool, but I don't want fire and/or consistent loud crackles necessarily. The idea of hitting a switch and going stock or cutout sounds pretty dang good to me.

Second goal is budget friendly.

much love,
Mario

[jwalker87]

If your goal is performance, then leave everything rearward of the downpipes alone. You didn't specifically mention it, but I assume that FBO includes catless downpipes. It should, since second to a tune, that is the best way to add power to an N54.

If you want some better sound after you install the downpipes and see for yourself (since that will make it louder by itself), I would recommend researching the PE-mod (PE for Performance Exhaust). It is relatively easy to recreate the BMW PE exhaust by replacing the resonator with an x-pipe as well as, inside the mufflers, either replacing the perforated pipe with solid, or sleeving the perforated pipe from the inside to achieve the same result. These don't really add any performance though, just sound.

Source: I have the N54, FBO plus a bit with the PE-mod, and love it.

[en_bloc45]

From what I've read constantly introducing and reducing back pressure isn't too healthy for our turbos. This all dependings on where you put the cut out. Post-cats should be fine since the back pressure compared to the cats is pretty minimal.

But Pre-cat is a difference story. You'll essentially be choking the turbos when the cut out is deactivated and then releasing the pressure when it's activated. If you want good sound wait until you install catless DPs because the rasp and rattle is pretty significant already. If you want something in the middle just install a few shortstack bottle mufflers to reduce the rasp, or just use resonators if you really wanna be loud.

Experience is being around different N54s with multiple exhaust set-ups. The best combo imo is catless DPs, resonators, high flow cats, with shortstack bottle mufflers (with PE mod).

[In54ne.e90]

Originally Posted by jwalker87

If your goal is performance, then leave everything rearward of the downpipes alone. You didn't specifically mention it, but I assume that FBO includes catless downpipes. It should, since second to a tune, that is the best way to add power to an N54.

If you want some better sound after you install the downpipes and see for yourself (since that will make it louder by itself), I would recommend researching the PE-mod (PE for Performance Exhaust). It is relatively easy to recreate the BMW PE exhaust by replacing the resonator with an x-pipe as well as, inside the mufflers, either replacing the perforated pipe with solid, or sleeving the perforated pipe from the inside to achieve the same result. These don't really add any performance though, just sound.

Source: I have the N54, FBO plus a bit with the PE-mod, and love it.

Originally Posted by jwalker87

If your goal is performance, then leave everything rearward of the downpipes alone. You didn't specifically mention it, but I assume that FBO includes catless downpipes. It should, since second to a tune, that is the best way to add power to an N54.

If you want some better sound after you install the downpipes and see for yourself (since that will make it louder by itself), I would recommend researching the PE-mod (PE for Performance Exhaust). It is relatively easy to recreate the BMW PE exhaust by replacing the resonator with an x-pipe as well as, inside the mufflers, either replacing the perforated pipe with solid, or sleeving the perforated pipe from the inside to achieve the same result. These don't really add any performance though, just sound.

Source: I have the N54, FBO plus a bit with the PE-mod, and love it.

Can I see any clips of it ?

[jwalker87]

Originally Posted by In54ne.e90

Can I see any clips of it ?

I don't have any of my car specifically, but check out these three youtube videos which all give you a pretty good idea. The first video has a sound bite of what I would call the only downside of the PE-mod, which is a bit of raspiness above 5k rpm or so.

[Freemorfeem]

Very helpful... lots to think about! Hmmm...

[NoGuru]

The stock exhaust flows really well so modding it is the way to go. I have an IS and it comes with a form of the PE exhaust plus I am catless and vibrant resonators in place of secondary cats. Here is mine.

[Freemorfeem]

So since I posted this I took my 335 to my local BMW Indy shop and the mechanic told me I already have aftermarket down pipes! No wonder mine sounds better than what I’ve heard from stock sounds in YouTube videos.

He said he couldn’t tell if they were High flow or not. Surely they’re not catless. My exhaust does NOT sound like Jwalker87’s.

But mine does sound similar to NoGuru’s exhaust.

I’d like a little more depth and grumble but with no performace gain in a cut out it’s not that important to me.

I wonder did my M Sport come with BMW PE?

I was going to do catted HF down pipes because I need to keep this emissions compliant.

Now I’m wondering what kind of down pipes I have and if I need to replace them or not.

If they are catted and high flow am I getting some performance gain? How can I tell what I have by looking?

I’m on vacation or else I’d go record some video of my exhaust sound for you guys, too.

I’ll need to Google search the things written about x pipes and anything “inside the muffler”. That’s new to me. It sounded like you were saying resonators added sound. But I was looking at resonated deletes for adding sound. So maybe I’m confused.

If my DPs are good and adding performance then maybe I only need a resonator delete to add a little more depth for a low cost and without being too loud.

Thanks a lot guys!

[BSM n54iS]

There are sticky threads at the top of each sub-forum, like this one for example:

https://www.e90post.com/forums/showthread.php?t=10687

Covers almost every exhaust out there minus the actual 2 valved exhausts I'm considering, the Turner Motorsport exhaust and the Fi exhaust (you don't want this one $$). But there are no real performance gains so I'd spend the dollars on fmic. Jack up the front of the car when you get home and have a look at your dp's, post a photo we can identify them pretty fast.

[Freemorfeem]

Dude thanks!

I’m wondering why my BMW mechanic of 30yrs couldn’t identify? Maybe it wasn’t a priority for him when he was looking. He thought I knew I had them.