Calling All N52 Owners With Headers

[STR8-6IX]

N52 owners, any of you considering/ looking to upgrade your stock manifold to headers?

looking at the OEM manifold design for the N52, its honestly one of the shittier designs. there is no piping which leads to the cats, meaning very little exhaust scavenging. the cats are infused right into the manifold for quicker warm-up which further reduces engine performance due to restriction. however, as for any other BMW the stock catback is really quite excellent expect for the main restrictions (secondary cat delete and muffler)

anyone out there with headers:
- any drone? how is overall performance
-how's the smell? is it bad, particularly when stopped with the windows down?
- what sort of catbacks are you guys running with the headers, anyone with stock catback? I have a magnaflow muffler and a secondary cat delete which I plan to be using for the header upgrade. I know it will be really loud, but would it sound good?
-what did you guys do for tune, like a proper ECU tune, trick the ecu into thinking cats are still there, or no tune at all?

thanks guys!

[crowtrobot]

Actually, just installed AA headers last weekend.

• Droned horribly with the BMW PE ~2400rpm under load. Swapped back to stock exhaust and it's practically gone.
• Smell's fine.
• As I said, BMW PE droned horribly. Also loud as hell. With stock exhaust, I can barely tell it's modified, slightly deeper sound.
• Tune came from AA as well. Adds some hp and reduces the trip point for the CEL (doesn't exactly trick the ECU into thinking the cats are there). Note: I didn't get a CEL after I installed them, though I only drove maybe 30mi before installing the tune.

[STR8-6IX]

Originally Posted by crowtrobot

Actually, just installed AA headers last weekend.

• Droned horribly with the BMW PE ~2400rpm under load. Swapped back to stock and it's practically gone.
• Smell's fine.
• As I said, BMW PE droned horribly. Also loud as hell. With stock exhaust, I can barely tell it's modified, slightly deeper sound.
• Tune came from AA as well. Adds some hp and reduces the trip point for the CEL (doesn't exactly trick the ECU into thinking the cats are there). Note: I didn't get a CEL after I installed them, though I only drove maybe 30mi before installing the tune.

in some cases, It takes much longer for the CEL to come on, a couple ignition cycles and it would turn on.

I think the reason why you had drone with the PE exhaust is because this cat-back deletes your factory resonator. if you deleted your secondary cats at a muffler shop (therefore keeping resonator) It will sound perfect, even with stock muffler and no drone.

anyways, thanks for your response. I am looking forward to installing headers in the future. curious to see how it will sound with my current catback setup (secondary delete + magnaflow muffler)

[crowtrobot]

Originally Posted by 6IX-F10-N52

I think the reason why you had drone with the PE exhaust is because this cat-back deletes your factory resonator. if you deleted your secondary cats at a muffler shop (therefore keeping resonator) It will sound perfect, even with stock muffler and no drone.

For the 128i, the PE is just an axle-back, cut into the pipe about 2" behind the stock muffler, no resonator delete unless I'm very confused. Secondary cats were still in place.

Like I said, stock exhaust and the headers is fine - no drone and virtually no increase in noise. That said, I do miss the sound of the OE manifolds and PE. Sounded perfect, IMHO.

[STR8-6IX]

Originally Posted by crowtrobot

For the 128i, the PE is just an axle-back, cut into the pipe about 2" behind the stock muffler, no resonator delete unless I'm very confused. Secondary cats were still in place.

Like I said, stock exhaust and the headers is fine - no drone and virtually no increase in noise. That said, I do miss the sound of the OE manifolds and PE. Sounded perfect, IMHO.

are you sure? im pretty sure the performance exhaust is a full catback regardless of which model it is fitted on. but if you had your secondary cats in place, then you probably had your resonator too.

your headers are a great start to getting the perfect exhaust sound for your car. I highly recommend you delete your secondary cats for starters, and then possibly switch out your OEM muffler with something better breathing. you can also try the "pe mod" to your OEM muffler, no loss in backpressure so it will not drone as long as you keep OEM resonator.

[crowtrobot]

Originally Posted by 6IX-F10-N52

are you sure? im pretty sure the performance exhaust is a full catback regardless of which model it is fitted on. but if you had your secondary cats in place, then you probably had your resonator too.

your headers are a great start to getting the perfect exhaust sound for your car. I highly recommend you delete your secondary cats for starters, and then possibly switch out your OEM muffler with something better breathing. you can also try the "pe mod" to your OEM muffler, no loss in backpressure so it will not drone as long as you keep OEM resonator.

Quite sure, did the cutting myself

Check this DIY for pics http://www.1addicts.com/forums/showthread.php?t=450937

I need the secondaries in for NYS inspection, while I don't have a CEL, they need to do a visual inspection to confirm at least something looks like a cat down there.

I am tempted to go to a 135i exhaust, as has been recommended by other board members, but not sure I want to spend more money on this right now. Already doing intake, and BWMP brake kit, may just deal with the loud-ass PE for track weekends and go back to stock otherwise.

[STR8-6IX]

Originally Posted by crowtrobot

Quite sure, did the cutting myself

Check this DIY for pics http://www.1addicts.com/forums/showthread.php?t=450937

I need the secondaries in for NYS inspection, while I don't have a CEL, they need to do a visual inspection to confirm at least something looks like a cat down there.

I am tempted to go to a 135i exhaust, as has been recommended by other board members, but not sure I want to spend more money on this right now. Already doing intake, and BWMP brake kit, may just deal with the loud-ass PE for track weekends and go back to stock otherwise.

so you had your resonator, and it still droned?? hmm.. what an unfortunate situation. you could've had a beautiful exhaust note with the right catback.

as for a 135i exhaust, I honestly wouldnt bother its the same thing but slightly freer flowing. the best thing for you to do it just simply find a muffler shop that will do the "pe mod" to your oem muffler, replace the two perforated pipes leading to the exhaust tips with steel piping. it will not drone and it'll sound good.

[markslc1]

[QUOTE[*]Tune came from AA as well. Adds some hp and reduces the trip point for the CEL (doesn't exactly trick the ECU into thinking the cats are there). Note: I didn't get a CEL after I installed them, though I only drove maybe 30mi before installing the tune.[/LIST][/QUOTE]

Interested in this. Because here in WA, you chant have ANY systems fail or not responding when passing emissions. did the AA tune clear everything? No cat codes or non responsive cat sensors?

[crowtrobot]

Originally Posted by 6IX-F10-N52

so you had your resonator, and it still droned?? hmm.. what an unfortunate situation. you could've had a beautiful exhaust note with the right catback.

as for a 135i exhaust, I honestly wouldnt bother its the same thing but slightly freer flowing. the best thing for you to do it just simply find a muffler shop that will do the "pe mod" to your oem muffler, replace the two perforated pipes leading to the exhaust tips with steel piping. it will not drone and it'll sound good.

Yeah, just with the PE. Stock is very comfortable (though you can still tell there's a little resonance at the same point, but only if you're really listening for it). I think others have used different exhaust systems with better effect. Bimmerbob, for example, used a Magnaflow cat-back I believe.

Originally Posted by markslc1

Interested in this. Because here in WA, you chant have ANY systems fail or not responding when passing emissions. did the AA tune clear everything? No cat codes or non responsive cat sensors?

There are not any cat codes, but I don't think the sensors are marked as 'Ready' either. Not 100% certain here - I can tell "no codes" from the Simon3 tool and verified it with the Torque app, but I'm not entirely sure Torque is reading the sensor readiness properly.

EDIT: post here shows what I'm seeing: http://www.1addicts.com/forums/showthread.php?t=1023386

[gixracer]

Just did AA headers with 3 stage IM, charcoal filter delete and it was fine. no tune at the time netted a spirited drive and bit of grumble over stock It did not trip the check engine light but I didn't drive it that far. Nothing to real write home as far as noise level. I did get the tune and AA's axle back.

Well I must say wow.

With the tune the car noticeably rev quicker(I have a manual), its great for heel toeing. The tone and attitude is very much increased in volume. Read it is heavenly when your foot is in it. while cruising it's mild mannered an with no noticeable drone.

This combination was well worth it, the car got some added HP, lost about 20lbs, and got a vocal attitude when asked. there is a small bit of burble on decell.

my 2 cents

[STR8-6IX]

Originally Posted by gixracer

Just did AA headers with 3 stage IM, charcoal filter delete and it was fine. no tune at the time netted a spirited drive and bit of grumble over stock It did not trip the check engine light but I didn't drive it that far. Nothing to real write home as far as noise level. I did get the tune and AA's axle back.

Well I must say wow.

With the tune the car noticeably rev quicker(I have a manual), its great for heel toeing. The tone and attitude is very much increased in volume. Read it is heavenly when your foot is in it. while cruising it's mild mannered an with no noticeable drone.

This combination was well worth it, the car got some added HP, lost about 20lbs, and got a vocal attitude when asked. there is a small bit of burble on decell.

my 2 cents

is the extra sound noticeable when you step on it?

any exhaust sound at all with the stock muffler?

plan to do any other exhaust mods?

[Bimmer-Bob]

BMWPE for the 128i is definitely just an axle-back - stock resonator remains in place. I used to have it, and installed it myself. I since have upgraded to AA headers, but I swapped out the BMWPE for a MagnaFlow cat-back at the same time, based on fears that the header + BMWPE combo would be loud and unpleasant. The MF unit replaces the stock resonator, but does not delete it entirely. Secondary cats are still in place with all off-the-shelf options, unless you get the SuperSprint straight pipes or race cats ($$) (or have custom work done at an exhaust shop, of course). The combo is subtle and civilized, but aggressive on throttle. Not much drone, and no smell, except every once in a while on a cold start in my garage (enclosed space, obviously). Main tune option is through AA, it seems like some people used to go with Evolve, although that option seems to have fallen off lately. The new thing I'm hearing about is BPC, out of North Carolina, but I haven't been interested enough yet to spend the money when I already have a tune. Good luck!

[Jrfly9]

I also installed the headers this weekend, it entirely changes the car! I wish there were more bolt on mods that could squeeze even more power out of my 128i; I have the N51 so it already has the 3 Stage Manifold.

- I have the PE exhaust. There is a drone at 2500 rpm, but it hasn't bothered me yet. On the freeway (~80mph) I am well above the drone, but it is loud. At 60mph in 6th gear the rpm is 2000, fairly quiet. I have only had the headers for a week, and while it is loud, I can live with it.

-My car only smelled bad before the tune because it was running very rich. Post-tune, no scent.

- I have the PE exhaust that others consider the loudest combination, and it is loud, but I don't think it is as obnoxious as the other members do. At WOT it sounds incredible and at cruising it draws attention; the sounds is definitely more on the side of car enthusiast than it is business professional.

- For my N51 motor I decided to go with AA. I have worked with them before and have had nothing but good experiences. However, I am not a fan of the Simon 3 cable system that they use for this tune. There are many other systems (across other platforms) on the market that are superior. Otherwise, love AA.

[STR8-6IX]

Originally Posted by Jrfly9

I also installed the headers this weekend, it entirely changes the car! I wish there were more bolt on mods that could squeeze even more power out of my 128i; I have the N51 so it already has the 3 Stage Manifold.

- I have the PE exhaust. There is a drone at 2500 rpm, but it hasn't bothered me yet. On the freeway (~80mph) I am well above the drone, but it is loud. At 60mph in 6th gear the rpm is 2000, fairly quiet. I have only had the headers for a week, and while it is loud, I can live with it.

-My car only smelled bad before the tune because it was running very rich. Post-tune, no scent.

- I have the PE exhaust that others consider the loudest combination, and it is loud, but I don't think it is as obnoxious as the other members do. At WOT it sounds incredible and at cruising it draws attention; the sounds is definitely more on the side of car enthusiast than it is business professional.

- For my N51 motor I decided to go with AA. I have worked with them before and have had nothing but good experiences. However, I am not a fan of the Simon 3 cable system that they use for this tune. There are many other systems (across other platforms) on the market that are superior. Otherwise, love AA.

hmm.. having a magnaflow muffler and secondary cat delete I feel like I will be on the same boat as you in terms of sound when I get my headers.. I just hope the smell wont be too bad. I'm happy with the current exhaust setup but its still a little bit too quiet for my taste to be honest. However, it doesnt rev nicer then before. smoother, more responsive and the sound is great. I'm very excited to get some headers.

[gixracer]

Originally Posted by 6IX-F10-N52

is the extra sound noticeable when you step on it?

any exhaust sound at all with the stock muffler?

plan to do any other exhaust mods?

yep there is more volume when you step on it
I really don't think there is much more to be had other than getting a section 2 to get rid of the secondary cats. The stock can had some sound with the headers but was not enough to make it have an attitude. i thought it was very chill without the AA axle back. I have a had a full bimmerworld on a s54 that was stupid loud. This is perfect. I have yet to notice any smell.

[STR8-6IX]

Originally Posted by gixracer

yep there is more volume when you step on it
I really don't think there is much more to be had other than getting a section 2 to get rid of the secondary cats. The stock can had some sound with the headers but was not enough to make it have an attitude. i thought it was very chill without the AA axle back. I have a had a full bimmerworld on a s54 that was stupid loud. This is perfect. I have yet to notice any smell.

I wouldnt get a midpipe because you are getting rid of your resonator as well which is something best left on. you lose torque from removing the resonator unless you fit an x-pipe (extra fabrication required for n52 exhaust system since there is one pipe leading from resonator to exhaust, not worth the effort)

the main reason for the secondary cats is to reduce the volume of sound and smell as well as provide some sort of filtration while your primary cats are cold and not functioning well. those of you who dont have a visual inspection, I recommend you remove them at a local muffler shop for like $140 CAD.

more engine sound, slighltly deeper exhaust note, better throttle response and a very satisfying top end pull. a noticeable 3HP gain from removing them . I've done it myself and was very pleased that there was ZERO drone. just keep the resonator intact and you wont have any drone people!

[KevM2]

Anyone get the aFe header? If so how does it sound? Any drone? Any CEL?

[Elias_E90]

Headers + bpc tune + secondary delete:
Performance : very very satisfied
Sound : I had a magnaflow muffler, car was too loud for me (with stock resonator), added 2 resonators straight through in the place of secondary cats, droned horribly between 1500 and 2400 rpm.
I put a more restrictive muffler instead of the magnaflow, drone was still there.
Now i reinstalled my stock muffler (drone is gone)
Smell: there is a smell like gasoline when stop + windows down, but it doesnt bother me. With the magnaflow the smell was huge (all straight through exhaust) and caused me headache (dunno if from sound or co emissions ) but with stock muffler no unwanted noise and no headache and smell is tolerable

Edit: car always sounded amazing above 3000 rpm, but it is my dd, cant live with drone esp. When windows were up, and worst was with ac on, cruising was too much drone + vibrations. Ps : drone was at its worst with the magnaflow:si

[Big Mexican Women]

Originally Posted by Elias_E90

Headers + bpc tune + secondary delete:
Performance : very very satisfied
Sound : I had a magnaflow muffler, car was too loud for me (with stock resonator), added 2 resonators straight through in the place of secondary cats, droned horribly between 1500 and 2400 rpm.
I put a more restrictive muffler instead of the magnaflow, drone was still there.
Now i reinstalled my stock muffler (drone is gone)
Smell: there is a smell like gasoline when stop + windows down, but it doesnt bother me. With the magnaflow the smell was huge (all straight through exhaust) and caused me headache (dunno if from sound or co emissions ) but with stock muffler no unwanted noise and no headache and smell is tolerable

Edit: car always sounded amazing above 3000 rpm, but it is my dd, cant live with drone esp. When windows were up, and worst was with ac on, cruising was too much drone + vibrations. Ps : drone was at its worst with the magnaflow:si

I am in the process of buying headers for my 328i, and I still cannot decide what setup to go with.

if you go for full catless headers, it might be a good idea to keep your secondary cats in place to deal with some of the smell.

currently, I am deciding between AFE catted headers with secondaries deleted, or supersprint fully catless headers with secondary cat in place.

next: resonator intact, and either BMW PE muffler or simply the stock muffler with the PE mod. if I go for the catted headers, I will probably replace my secondary cats with two resonators like you did.

A friend of mine has a 335i with catless downpipes, secondaries in place, upgraded x-pipe and two resonators where the muffler was supposed to be. very good sound, but even with the secondary cats in place it still smells strongly of gas when stopped. this is what I want to avoid.

the N52 sounds very raspy with headers, but this is what i'm trying to avoid. I am not going to keep the stock manifold either way because like the OP mentioned, it truly is a very bad design.

[Elias_E90]

Yes it is very subjective (the loudness). I like a bit of rasp, lots of e46 m3s had rasps. But the drone is what i hate because the car is daily driver + auto

[desertman123]

Originally Posted by Big Mexican Women

I am in the process of buying headers for my 328i, and I still cannot decide what setup to go with.

if you go for full catless headers, it might be a good idea to keep your secondary cats in place to deal with some of the smell.

currently, I am deciding between AFE catted headers with secondaries deleted, or supersprint fully catless headers with secondary cat in place.

next: resonator intact, and either BMW PE muffler or simply the stock muffler with the PE mod. if I go for the catted headers, I will probably replace my secondary cats with two resonators like you did.

A friend of mine has a 335i with catless downpipes, secondaries in place, upgraded x-pipe and two resonators where the muffler was supposed to be. very good sound, but even with the secondary cats in place it still smells strongly of gas when stopped. this is what I want to avoid.

the N52 sounds very raspy with headers, but this is what i'm trying to avoid. I am not going to keep the stock manifold either way because like the OP mentioned, it truly is a very bad design.

I got a muffler delete, catless AA and still have my secondaries. It only smells on a cold start. If I'm stopped at a stoplight fully up to temp with my windows down, I don't smell a thing. I also don't have any CELs which is odd, but it does throw codes for catalysts if I scan with INPA.

https://youtu.be/u8Epqe1K_3g

[Big Mexican Women]

Originally Posted by desertman123

I got a muffler delete, catless AA and still have my secondaries. It only smells on a cold start. If I'm stopped at a stoplight fully up to temp with my windows down, I don't smell a thing. I also don't have any CELs which is odd, but it does throw codes for catalysts if I scan with INPA.

wow, that actually sounds quite good! far better than I thought it would, anyways.

will you be doing anything else to your exhaust system? I think some sort of high-flow muffler at the end and this exhaust setup would be just about perfect for me.

It says you also have a 3 stage manifold. I am hoping you will be getting a tune for this and your headers, because you won't be getting the optimal gains if you don't. The CEL will pop up in due time..