[mmmnot]

OKAY. So, I have had these headers for a few months now and I keep hear/seeing posts asking about N52 headers other than AA or headers with cats. So, as suggested, rather than keep posting in different threads, I'm going to put everything up here.

Disclaimer: I have NO affiliation with AFE, I am NOT a mechanic. I am a computer science major so any claims or theories put out here should be taken with a grain of salt. Furthermore, if this violates any forum rules, please edit and do no delete or let me know my errors and I will rectify ASAP.

Engine/Car:

2009, AT 328i N52.

Modifications PRIOR to Headers (engine/performance):

Dinan catback exhaust
Dinan ram intake
Secondary cat delete
RPI intake scoops
BMS powerbox (which was replaced, more below).

Storyline:

So, much like many of you, I grew bored with the N52 powerband. Upon many months of research (and as AA was releasing their catless header) I decided that emissions issues and CEL would just drive me nuts. For a DD, I do not need to jump through hoops to pass emissions. I research AFE as a company as a hole and then specifically their headers with high flow cats.

Based on the research and their power claims - not to mention I would pass emissions, I hit the buy now button. I would never look back from time period again.

Here is the details on their website: http://afepower.com/shop/details_new...artno=48-36307

The thing that sold me was not only emissions being a cake walk, but their dyno graph:


The above image is provided by AFE and NOT my own dyno*

So, about ten days later, these beauties come in the mail:



First off, let me stop by address the build quality. Top. Notch. The welds were almost a work of art, the bends made engineering and logical airflow sense and they weighed 12lbs lighter than OEM headers/manifold even considering they had high flow cats installed.

Note the flanges, the thickness was something that made me feel warm and fuzzy inside because to me, that indicates a proper build process and they did not get lazy on items. It spoke very highly to me, yes, these small things really matter and you should really pay attention to some products you buy, won't mention names here, but you get the point. (No, no - not AA, a more 'generic' reseller).

I looked up DIY, I forget his username, but he has the 130i had an awesome (I believe it was you) thread. Being mechanically disabled, I opted to have a shop install them. It was about 5 hours shop time, so that would mean 5 weeks my time. No regrets there, ego hurt but I'll recover.

Back on track, I literally just kept my phone at my desk and kept looking at it praying the shop would call and say, all good - come pick up. Finally, they did. I left work early and bailed out to see my sleeping beauty.

Results:

The results were very impression. From the initial start, the car sounded WAY more aggressive, slight rasp, yes - I will not lie, but I think that's due to any header system in an inline 6 engine. The cold start idle literally sounded like a V8 'camming'.

I put about 100 miles on the headers and watched as they went from a silver metallic stainless to a nice golden color from the heat, which I find beautiful:



It's just so, so pretty to me

So, a few more miles later, I had the dyno itch craving. Well, maybe buyers remorse in a way. "What the hell did you do, Josh? This is a few mortgage payments, this is an LSD, this is ___________" I needed a dyno to be assured I had made the right choice. So, called up the shop and did my first dyno in my BMW. The results, I would say, are very impressive. I instanatly stopped crying over lost money and started to plot new upgrades, a 330 manifold and tune.

Here is the dyno with ONLY afe headers, intake scoop dinan intake, 2nd cat delete and dinan catback (all of which, minus headers offer substantial gains IMHO)



I was very, very, very impressive with the gains over stock. I was so excited.

Now, I knew I had to do more. So, from there, I took off the BMS power box tune and installed a 330 intake manifold then purchased a proper tune from AA. Both of those items are NOT in the dyno and I am currently pending a NEW dyno next week.

Sound clips or GTFO you say? As you wish. Below is a video of my car with ALL mentioned mods, you can get an idea of the rasp, which I mostly contribute to the 2nd cat delete, but I enjoy it and it is very loud (SIC).

This was a warm start and I wish I had audio from a non stationary situation, but at this time it is all I have. I am hoping to be around the 250whp mark with the current final mods.

So, all in all - if you're worried about AA's catless headers like I was, this is a very viable option that offers some amazing improvements as well as audible enhancements.

There you guys go.

Any questions/comments/concerns - please post. I'll be glad to help answer any questions.

[Tom Droze]

I first want to say my decision to buy the AFE catted headers and Supersprint mid pipes were do in large part to your previous posts. Both items should be waiting for me when I get home this evening. I too had emission concerns and with previous cars, when I did a primary cat delete, the exhaust smell could become overwhelming at times. I have a N51 so it will be interesting to see how it responds to a less restrictive exhaust. Fortunately, Arizona is not a N51 mandated state. I am also hoping this set up helps to cure my M3 fever, which I've concluded is as a result of the lure of a V-8 roar. Not that I'm expecting that type of exhaust note, but a meaner exhaust note should be, to some extent, more satisfying. Thank you for a very detailed write up, and pretty soon we will be AFE header brothers in arms.

[JDane07]

What kind of dyno did you use?

[mmmnot]

Originally Posted by Tom Droze

I first want to say my decision to buy the AFE catted headers and Supersprint mid pipes were do in large part to your previous posts. Both items should be waiting for me when I get home this evening. I too had emission concerns and with previous cars, when I did a primary cat delete, the exhaust smell could become overwhelming at times. I have a N51 so it will be interesting to see how it responds to a less restrictive exhaust. Fortunately, Arizona is not a N51 mandated state. I am also hoping this set up helps to cure my M3 fever, which I've concluded is as a result of the lure of a V-8 roar. Not that I'm expecting that type of exhaust note, but a meaner exhaust note should be, to some extent, more satisfying. Thank you for a very detailed write up, and pretty soon we will be AFE header brothers in arms.

You're going to love it man:

Originally Posted by JDane07

What kind of dyno did you use?

Sorry for lacking that information. It was a standard dyno jet? (Not mustang)

[StealYourFace]

Nice!

You mention that you are happy with the dyno... did you have a baseline before the headers??

[mmmnot]

Originally Posted by StealYourFace

Nice!

You mention that you are happy with the dyno... did you have a baseline before the headers??

No. I wish I did. I simply relied on afes before graph as a reference.

[mlifxs]

any drone before or after?

[Tom Droze]

They are a thing of beauty!

Now, for the BIG question, should I attempt the install tonight? Hmmmmm. . .

[Taskmaster]

Yyyesssss

[NJ Krish]

Can't wait to see dyno with tune and IM. Great review! Also I agree with you on how awesome they look after the heat!

Also, shout out to CS majors haha

[Eagle1oh7]

I'm considering getting the aFe headers over the AA due to the emissions, but I'm still on the fence until such time when I do them later this year or next year.

[chris82]

Originally Posted by mmmnot

Nice review OP, they look as you say they do. I don't doubt AFE makes a great product

Originally Posted by Tom Droze

They are a thing of beauty!

Very nice

Can't wait to see your results Tom Droze, I too have the N51

[pinoye90]

This is my next upgrade!!! Legal and power you can't loose.

[94marcus]

n51 represent!!!

[andrey_gta]

Awesome mod review
These are tempting once I see a tune/manifold/high flow dyno. The loss versus a real header may be worth it for the easy life.

So I guess Afe dyno plot didnt lie and these can be compared to all the plots TheAxiom made. The bad news is that all those air intakes can't really claim 12-15 hp increases.

OP not to discourage you. BUt don't know if you will see a 250whp number after manifold plus tune. That is maybe real headers territory if I recall correct.
I predict something like 235-240whp based on intuition.


Which tune will you do: a off road header tune or a typical manifold only tune? Will a tuner like AA allow header tune on this? Because Header tunes differ than just turning off the CEL, wonder if the 300 CEL can handle it...

[94marcus]

Originally Posted by andrey_gta

Awesome mod review
These are tempting once I see a tune/manifold/high flow dyno. The loss versus a real header may be worth it for the easy life.

So I guess Afe dyno plot didnt lie and these can be compared to all the plots TheAxiom made. The bad news is that all those air intakes can't really claim 12-15 hp increases.

OP not to discourage you. BUt don't know if you will see a 250whp number after manifold plus tune. That is maybe real headers territory if I recall correct.
I predict something like 235-240whp based on intuition.


Which tune will you do: a off road header tune or a typical manifold only tune? Will Afe allow header tune on this?

i think the manifold tune will be the only thing he needs the off road header tune is just to get rid of CEL i think although im not too sure

[StealYourFace]

Ugh so conflicted!

I just don't know if carless headers are worth the BS for an extra what, 5-10 over these?

What I do know is that my car certainly starts to dog down a little about 15 min into a session at hpde when my 150k plus mile cats start to heat up

[Taskmaster]

Originally Posted by StealYourFace

Ugh so conflicted!

I just don't know if carless headers are worth the BS for an extra what, 5-10 over these?

What I do know is that my car certainly starts to dog down a little about 15 min into a session at hpde when my 150k plus mile cats start to heat up

Go catless and leave the secondaries.

[Route 16]

Did AFE say what cell count are the cats to make no CEL come up? 200, 400? If you can find out that out, I would rather buy AA headers, ask them to weld what I send them (I know the amount to weld/fit would cost maybe close or up to AFE's price on top of my own cats sent).

[StealYourFace]

Originally Posted by Route 16

Did AFE say what cell count are the cats to make no CEL come up? 200, 400? If you can find out that out, I would rather buy AA headers, ask them to weld what I send them (I know the amount to weld/fit would cost maybe close or up to AFE's price on top of my own cats sent).

300 cell

[StealYourFace]

Originally Posted by TheAxiom

Go catless and leave the secondaries.

That was my original plan and prob makes the most sense and will cost a lot less (because I would obviously do the catless secondary pipes with the afe headers) and just spend the extra hundo for the catless AA tune.

I wonder what kind of shape my 160k mile old secondary cats are in though....

We just put a set of LS7 manifolds/cats on my dad's LS3 vette... so there is a pair of 2.5" oem corvette cats with only 15k miles on them. I thought about doing AA headers, and getting the AFE secondary pipes and welding in the corvette's cats.... and doing a crossover tube before the cats

[Taskmaster]

Well?