Everything You Need to Know About E46 Headers, Including Dyno Numbers! 

The O2 sensors do not make any changes to the fueling when the car is at full throttle. The MS42/MS43 ECU takes the fuel trims made when cruising and just multiplies them by a set amount whenever it enters the full load state causing the so called full load enrichment. You just need to alter the base fuel map, or change the multiplication factor for the Full load state which should give you the lower AFR and thus more power. Vanos is where the big gains are when installing aftermarket headers. The EX vanos can be altered and then the IN to match. I won't go into to much detail, since I am not really sure as to what the tuners actually change, but there is some info on the net which I am attempting to decipher with the help of datalogging.

Will require a tune to actually see the benefits.

1. Ebay headers are the worst aftermarket sport headers on the market. 2. You eliminate the cats, so you losing lot of exhaust gas pressure (that is studied in the original project of the engine). 3. The Ecu is still on original parameters, that is absolutely wrong if you want to get power by your exhaust and not only loudness. You're talking about afr... that's it and many other things that your ecu should know now to work at 100% on your engine. By the way.. the video is good, keep up man. I'm an e46 owner too. 330ci. And sorry to all for my BAD english, i cannot explain very well the same things that i would say in Italian :)

Great video! Thanks! Will be watching for more!

Great video. I like how you approached things with an open mind and a reasonable hypothesis

Great and helpfull video! Thank you!

Very well done video, deserves many more views

I bought that same header for me e46. I had to go through everything u went through. Front 02 still had mad issues. Plus grinding down my after market o2 90 to get it to fit. Bonus is the 90 gets a if of o2 light. I spent 450 on my 100$ eBay headers after it was all said and done. Hope to never have to go through that again.

Good quality video...I was gonna buy headers instead of reinstalling the factory exhaust manifold. Leaving the factory pipes and mufflers. My hope is the headers will be easier to install because replacing a head gasket is a pain in the ass.

Got to be honest the after dyno means nothing because by your own admission the check engine light is on and you aren’t running all the o2 sensors. The car has dropped into a base map. That’s why the afr is wrong.

When doing this dyno tests you need to be sure, that you have fresh Air flow meter and intake is tight (especialy CCV). MS43 ECU works in open loop on WOT, based only on air flow of that vanos, ignition and fuel is adjusted, if Air flow meter does not see additional flow engine (due to numerous reasons) wont be working in perfect operating order and you won't see any gains. Additional super important thing is air temperature, M54 is very sensible for hot air in the intake so if you take test in two different days and ECU will take 2 degrees of timming due to temperature you can see easily 10-20 ponies out on the crank. So this test is only true if you have all of the above in perfect operating condition. Based on stock headers design ANYTHING you do in that area should provide significant gain if you do not have bottleneck anywhere else.

Great video! I bought EBay headers to delete the stock cats. Those stock CATs are ridiculous as they broke inside one of them and embarrassingly rattled all the time (I cut it open and the top honeycomb piece broke loose). Get the eBay headers and problem solved lol. Add a resonator in between the exhaust and a good 2-chamber or HKS muffler and it will be glorifying! 3- chamber muffler if you want it quieter. Always delete the CATs…

the thing is after installing headers youll need a tune and thats where the performance gains will come in

I don’t know much of the m54tub28 but for the m54b30 I can’t say myself but through several forums people can gain 15-20hp with the m54 since the stock manifold is trash, but obviously needs to be tuned

Simply speaking: "Headers" have the same principle as a burning chimney stock the higher the pipe is the more suction there is and therefore more combustion per One cycle. The exhaust portion of an engine is important, however, these cars have ECU and it runs the same values all the time. Headers will absolutely make the driving experience better, it is noticeable but an ECU flush may be beneficial.

Awesome video bro! Better than other more “popular” car review channels. Hoping your channel gets more views because it definitely deserves it with the quality work you put into everything. Overall keep up the great work

I installed ebay headers on my old E46 paid $400 CAD for install. Now, with my new E46 with stock headers, I was debating whether to get headers again because this time, I was hoping to get more out of them with a tune (since the tuners claim that you'll get more out of a tune with more bolt-on mods like headers/free flowing exhaust etc), but after watching this, it's clear that even with a tune, the headers don't make much difference. Thanks for this video - I will instead go with my original plan to keep the benefits of the cats (smell) and just go muffler delete with resonators. You rock, Jake. this video came at the perfect time.

One guy did schmidemann headers + full exhaust and remap and car did 235chp. Stock they put out 205chp. And runs 14.1 at 1/4 mile.

Yeah should have performance tuned with and without headers, what's the relevance if it's not tuned to optimize the Installed performance parts?

I think everyone who has done fair enough work on cars knows that u have to tune your car with mods especial efi cars. U leaving out a tune isn't fair cause u need a tune to take advantage of it.

LOL you need to optimized the VE Table after any Modification from Induction system to Exhaust system.

I was about to ask why everything relevent to power and tuning, Or even a remap needs to be a different story for another vid, tben i noticed i was 10 minutes in. Any car without a carb will compensate for changes to available oxygen. Was just wanting to know if the headers are any good.

I put eBay headers on my 02 e46 325i and I had the same fitment issues with the o2 sensors and just plugged the hole up lol but the car has a strong gas smell while I’m driving or idleing with the window down which is kinda annoying

You should get the ebay headers tuned in and dyno it again! Not much dyno data on this with a proper dial in tune.

See weird thing is my 2000 323 came with the M54 inline 6, but then again its shipped directly from Germany

Got a set of headers in the trunk of a car I bought for the transmission so I don't know if they're ebay headers or not but I suspect they are, I had zero issues with installation on a '04 330i everything lined up perfectly (except for upstream O2 sensor, plugged that hole) I live and drive at around 7,000' elevation in the mountains of Utah and I can say that without a doubt they add more than 2 or 3 hp. Idk much about all the dyno number mumbo jumbo but I know a engine is a big air pump and the more air you can move through it the better and headers are a way better option, my butt dyno says 10-15 hp no problem, fight me.

What muffler are you running?

how much was the dyno tune at this location for you?

Very good video. Finally dynotest and fact about this. Next video idea : Myth of "cold air intakes" and power gains? =)

engine should be tuned on stock manifolds, then swap the headers and then retune. this is how you test headers. both setups needd to be optimised. By the same taken if you are bone stock and add headers and a tune then some gains are the the optization of the tune that would have still occured even on stock manifolds.

Thanks so much for creating this video and dispelling some common myths. First of all, don't understand why anybody would purchase no name parts from Ebay, although many people think it is a great idea. It seems that the only thing headers do well is create noise and do virtually nothing for power and efficiency. I will try to find some test data for the Active Autowerke Performance Catless Header Set, but at this point, things are not looking too good.

So is it more of a placebo effect

The m52tu2.5 only produced 168 at the crank and the 2.8 was 190 and we all know u loose about 20% through the drive train, so how are u getting so much whp? Jts.my understanding there really isn't a whole lot u can do to squeeze out any real gains from these very low hp but very reliable little.six bangers except cams. I mean u cam stroke em I guees but why when s54s or even LS motors swap pretty easily relatively speaking of course. Id be interested in knowing what u did sin e i.own 2 e46s both with m54b25s. Thanks for letting me in on the secrets!

Also. You need to do intake header and exhaust together as they work together to get full potential from each part. Not to mention a tune (as u mentioned) when your done. Liked and subbed!

Can you tell me what are those wheels that are on car and are they same to ones that you've sat at the start of vid? BTW nice channel :D

2.5 horse power for 100 dollars in Bolton’s is worth it’s weight in gold. Specially with out a tune. For all those saying that people’s feelings got hurt, stick to your mechanic. With a tune these headers get 10-15 horsepower gain. At least my 2001 M54B25 did. Have know clue why know why a E46 would have a E36 engine but ok

Totally should have did a cold air intake with the headers than your numbers would have been way different

anyone know which ebay or amazon headers fit the best with the least modifications for e46 330i?

Everyone that reads e46 forums just had their hearts broken.

Has anyone here actually fitted ebay headers?.and had a remap? Obviously if you dont remap ur efi they wont make any difference but im just wandering if anyone who had a remap had any good results from the ebay kit. Im on a budget and was trying to find out if the hype is real?

Why would it make significantly more power without a tune. It’s only worth it if you get a tune xD

Are you able to post the link to the headers. And do you just have a straight pipe from headers back?

What size tire are you running on your style 5s?

New link

Just changing headers isnt gonna add power like that🤦🏽‍♂️now do an intake and TUNE IT yes. Cold air intake mounted behind foglight, M50 intake manifold, M54B30 cam and ebay headers with a good tune on a B28 should net you about 220-230 wheel

Oh yeah really gotta spray that tire sticky on the dyno for the e46 loooool I can laugh at that I'm a long time e46 owner(and 325 owner at that lmao) lol

Is eBay the only place to get e46 headers or no cause I’m not trying to buy cheep China parts

bruh you gotta get a tune for it😂

you need full exhaust to see any real difference. and you failed to mention a tune. did you have one or not. that is everything. to the people here late, do full intake and exhaust 3 in 3 out and get a proper tune and then tell me the difference. headers alone wont do much

you would see better gains if you got a tune

That's an obnoxiously loud 178 whp.

Jesus christ lol. I was expecting more. I ran into issues with my ebay headers hitting my frame and I have a small exhaust leak near where it mounts to my head. I should have tap the extra bolt holes for my headers when my engine was out.

323i M52 sounds much bettet than a M54 328i

with a tune you will get the other 7hp.

Also if ur CEL is on. That will affect air/fuel, ultimately affecting power

Shit I want to like the video but the likes are 325. I feel i cant like this in respect of the 325i

Horse power is horse power 🤷🏼‍♂️

I love when facts are actually proven, but stupid people still believe the advertisement!

Why are u talking like that?

GET A TUNE DORK 😂 HIT UP REVMATCH MOTORSPORTS