[The Nightman]

Originally Posted by 6ixSpd

No modifications to anything. Straight plug and play.a

Thanks for the response! I wonder if it's different for automatics?

Do you have more photos of the Roundel Werk headers? The pictures on their site look the same as the usual eBay headers but your headers here look a little different. Eg the O2 sensor bung on yours are in a different location

[6ixSpd]

I believe their photos online are the old batch. I looked into it, and that's the updated headers that I've received.

[desertman123]

Originally Posted by freedomfries

Did you have to modify the engine mount or headers to get them to fit? I'm thinking of changing my exhaust set up to catless headers + stock exhaust

Bend the motor mount heatshield out of the way so it doesn't rub though

[dwashy]

Originally Posted by desertman123

Bend the motor mount heatshield out of the way so it doesn't rub though

I had to do that. Anger helped quite a bit haha

[M_Torx]

I have primary cats and right at the flanges after o2 sensor where exhaust starts to go straight back I got a custom y pipe into a 3inch all the way back with a straight threw 3inch muffler with (holes) on inside for a little back pressure and it sounds insane really deep not raspy at all lots of burbles and pops at redline between shifts and below 4K just reving

[dwashy]

Originally Posted by alexprehn

I have primary cats and right at the flanges after o2 sensor where exhaust starts to go straight back I got a custom y pipe into a 3inch all the way back with a straight threw 3inch muffler with (holes) on inside for a little back pressure and it sounds insane really deep not raspy at all lots of burbles and pops at redline between shifts and below 4K just reving

Make a video

[The Nightman]

Which gasket do we use between the engine and headers? The OE ring gaskets (#18407530606) or the included gasket?

Included gasket:


OE ring gasket:

[hassmaschine]

Wow. Those gaskets look like crap IMO. I would use OE if they fit. Those sandwhich style are likely to leak, as the N52 exhaust ports were never meant to seal that way. Is that what everyone else with headers uses?

[Biginboca]

Originally Posted by hassmaschine

Wow. Those gaskets look like crap IMO. I would use OE if they fit. Those sandwhich style are likely to leak, as the N52 exhaust ports were never meant to seal that way. Is that what everyone else with headers uses?

My AA headers came with the OE style ring gaskets.

[6ixSpd]

As an update on my exhaust setup, despite adding a Vibrant resonator to the Magnaflow muffler (stock secondary cats are still there) it's still too much drone. I'm going to swap in a stock muffler as I'm tired of wasting money hacking up the OE system and still having drone.

Originally Posted by Biginboca

My AA headers came with the OE style ring gaskets.

Same. My Roundelwerk headers (which I swear are AA replicas/suppliers lol) came with OE type gaskets even though the picture showed the sandwich style ones.

[doogee]

Originally Posted by 6ixSpd

As an update on my exhaust setup, despite adding a Vibrant resonator to the Magnaflow muffler (stock secondary cats are still there) it's still too much drone. I'm going to swap in a stock muffler as I'm tired of wasting money hacking up the OE system and still having drone.


Same. My Roundelwerk headers (which I swear are AA replicas/suppliers lol) came with OE type gaskets even though the picture showed the sandwich style ones.

Correct. Roundelwerk headers now come with OEM style ring gaskets and are an updated design which do not interfere with the engine mount heatshield.

The O2 bungs have also been moved to the lower section of the header.

[FlaPatsFan]

Hey guys....question for those with AA headers or similar. I just installed mine, but also deleted the secondaries awhile back.

So...I love the sound with the resonator and AA Gen 2 axel back. The whole system works well together. However it is a bit loud. Especially when I get in the throttle. I am contemplating putting the secondary cats back in.

Anyone been in my situation or done this? Just wondering if the secondaries will help tone it down a tad?

[Biginboca]

Originally Posted by FlaPatsFan

Hey guys....question for those with AA headers or similar. I just installed mine, but also deleted the secondaries awhile back.

So...I love the sound with the resonator and AA Gen 2 axel back. The whole system works well together. However it is a bit loud. Especially when I get in the throttle. I am contemplating putting the secondary cats back in.

Anyone been in my situation or done this? Just wondering if the secondaries will help tone it down a tad?

Wait a week before you do anything. If you have the factory resonator then we now have the same set up and I think it will grow on you!

I have AA Headers, SS Secondary Cat Delete, Factory Resonator, and AA Gen 2.

[FlaPatsFan]

Originally Posted by Biginboca

Wait a week before you do anything. If you have the factory resonator then we now have the same set up and I think it will grow on you!

I have AA Headers, SS Secondary Cat Delete, Factory Resonator, and AA Gen 2.

Will do, I haven’t driven it to much yet. But will be heading up to Tampa on Wednesday to get the AA re-tune.

Yes we have almost the same set up. However I replaced the factory resonator with a smaller custom one. Not sure if that will make that much of a difference tho. I must say car is pulling much better thru the mid range RPMs now!

[Taskmaster]

Originally Posted by FlaPatsFan

Will do, I haven’t driven it to much yet. But will be heading up to Tampa on Wednesday to get the AA re-tune.

Yes we have almost the same set up. However I replaced the factory resonator with a smaller custom one. Not sure if that will make that much of a difference tho. I must say car is pulling much better thru the mid range RPMs now!

It really won’t, it will take away some of the rasp.

Just get a bigger muffler, that’s all you can really do.

[desertman123]

Originally Posted by Biginboca

My AA headers came with the OE style ring gaskets.

Yes I just used Mahle gaskets for the head and midpipe

[FlaPatsFan]

Originally Posted by Taskmaster

It really won’t, it will take away some of the rasp.

Just get a bigger muffler, that’s all you can really do.

Are you referring to putting the secondaries back in? Or getting a different resonator?

As for changing to a larger muffler I doubt I will do that as the AA Gen2 set up was pricey to begin with. As BB said I’ll prob wait a week or so and see how it settles in then decide.

[Taskmaster]

Originally Posted by FlaPatsFan

Are you referring to putting the secondaries back in? Or getting a different resonator?

As for changing to a larger muffler I doubt I will do that as the AA Gen2 set up was pricey to begin with. As BB said I’ll prob wait a week or so and see how it settles in then decide.

It will break in and get a tad quieter, but I would look into getting an inline muffler put in.


I keep on telling everyone, and I'll keep on saying it - Catless headers and aftermarket exhausts are going to be loud - period. You can reduce the volume with more mufflers or going back to a stock exhaust.

[atmosphericM]

This is now at least two data points I've noted in which it seems that the factory resonator actually does quite a bit of sound attenuating. I was always surprised at Big's results and now I'm convinced it's due in part to the OE resonator. I'd be willing to bet that Big's setup is a bit quieter than PatsFan's because aftermarket resonators don't seem to do a whole-whole lot, typically.

Here is a photo of the inside of a 330i resonator, and you can see that its design is quite a bit different than that of, say, a Vibrant resonator. More room (volume), lots of 'packing' (already removed before taking the above photo), and also, depending on if those two 'chamber walls' are perforated, something must be going on in there to deaden the sound. Who knows - I'm on fluid dynamics engineer, but perhaps the fact that the resonator is JUST after the Y merge has something to do with it, as well.

OEM:



Aftermarket (typical):

[Taskmaster]

Originally Posted by atmosphericM

This is now at least two data points I've noted in which it seems that the factory resonator actually does quite a bit of sound attenuating. I was always surprised at Big's results and now I'm convinced it's due in part to the OE resonator. I'd be willing to bet that Big's setup is a bit quieter than PatsFan's because aftermarket resonators don't seem to do a whole-whole lot, typically.

Here is a photo of the inside of a 330i resonator, and you can see that its design is quite a bit different than that of, say, a Vibrant resonator. More room (volume), lots of 'packing' (already removed before taking the above photo), and also, depending on if those two 'chamber walls' are perforated, something must be going on in there to deaden the sound. Who knows - I'm on fluid dynamics engineer, but perhaps the fact that the resonator is JUST after the Y merge has something to do with it, as well.

OEM:



Aftermarket (typical):

No, and also no.

It's not muffling sounds at all, the noise reduction is mostly a result of the exhaust gas merger (Y pipe)

Resonator's don't quiet exhausts - they CAN, but that's not their job and they shouldn't be used for that purpose.

[FlaPatsFan]

Interesting points guys. I will prob take my car to my exhaust guy and see what he suggests. I’ll wait a week or so then go to him. I may do what BB has and put the stock resonator back in instead of the secondary cats.

[Taskmaster]

Originally Posted by FlaPatsFan

Interesting points guys. I will prob take my car to my exhaust guy and see what he suggests. I’ll wait a week or so then go to him. I may do what BB has and put the stock resonator back in instead of the secondary cats.

Just put another muffler in line - I've said this twice now in this thread.