What exhaust setups do you N52 guys have?

[STR8-6IX]

I have a 2011 528i f10 rwd with the n52 engine. curious to see what people are doing with the same engine. currently I have a secondary cat delete and magnaflow muffler. I have wanted to install catless headers for a long time now but my DME is untuneable..

what do you guys think of my exhaust setup, and what have you guys done? I have sound clips if anyone is interesting. my perfect exhaust setup for this engine would be catless headers, secondary cat delete, resonator intact and either PE mod 28i muffler or borla muffler. magnaflow will be too loud with catless headers but it sounds great for now.

[3002 tii]

Guess it depends on what your goal is and what compromises you're willing to make. But why is lack of tuning holding you going forward with headers? If it's because you need to pass emissions, you can just buy the o2 sims from Are@Seventy4. That's what n55 folks have used in last year or so to pass emissions with catless dp's.

I've gone through quite a few different exhaust configurations and if I were to start from scratch for a car that's driven regularly, I would run:

Catless headers -> factory secondary cats -> Y merge to single 3" right before where the factory resonator sits. Then throw in an inline resonator and finish it off which muffler of your choice.

[STR8-6IX]

Originally Posted by 3002 tii

Guess it depends on what your goal is and what compromises you're willing to make. But why is lack of tuning holding you going forward with headers? If it's because you need to pass emissions, you can just buy the o2 sims from Are@Seventy4. That's what n55 folks have used in last year or so to pass emissions with catless dp's.

I've gone through quite a few different exhaust configurations and if I were to start from scratch for a car that's driven regularly, I would run:

Catless headers -> factory secondary cats -> Y merge to single 3" right before where the factory resonator sits. Then throw in an inline resonator and finish it off which muffler of your choice.

wouldnt the AFR be all messed up if I install catless headers without a tune? and I am pretty sure you do not get all the gains you otherwise would. my understanding is that the ECU can adjust to catback changes, but not for primary cat changes.

do the secondary cats help reduce smell? I removed those (since I still have primaries) and it freed up maybe 3HP particulary in the high end, I thought this would be of importance to you based on how you plan to drive your car. But I understand if it is because of smell.

[3002 tii]

Originally Posted by STR8-6IX

wouldnt the AFR be all messed up if I install catless headers without a tune? and I am pretty sure you do not get all the gains you otherwise would. my understanding is that the ECU can adjust to catback changes, but not for primary cat changes.

do the secondary cats help reduce smell? I removed those (since I still have primaries) and it freed up maybe 3HP particulary in the high end, I thought this would be of importance to you based on how you plan to drive your car. But I understand if it is because of smell.

A tune would help but it's not necessary. My point is you'd still see solid gains with just headers alone so I wouldn't let lack of tuning stop you if going catless is your ultimate goal.

Yes secondaries will help with the fumes as they're essentially mini cats. I'm actually in the opposite camp that I don't think it's worth taking out the secondaries. I mean if that number is right are you really going to tell a difference of +3whp? That's like the car feeling lighter because you took a massive dump before getting in the car.

[STR8-6IX]

Originally Posted by 3002 tii

A tune would help but it's not necessary. My point is you'd still see solid gains with just headers alone so I wouldn't let lack of tuning stop you if going catless is your ultimate goal.

Yes secondaries will help with the fumes as they're essentially mini cats. I'm actually in the opposite camp that I don't think it's worth taking out the secondaries. I mean if that number is right are you really going to tell a difference of +3whp? That's like the car feeling lighter because you took a massive dump before getting in the car.

If you have primary cats then secondary delete is a great way for some basic exhaust flow improvement which still passes emissions with no problem. otherwise you're right its probably best to keep em anyways.