3.0i headers

[Joshdub]

Also if anyone has any before and after sound clips that would be awesome.

[tecboy99]

I don't have a stock muffler clip, but I have a clip with 4.8is mufflers before and after the headers.

4.8is mufflers without headers - https://www.youtube.com/watch?v=xUM0...ature=youtu.be
4.8is mufflers with headers - https://www.youtube.com/watch?v=fjIKys6Dljg

[Joshdub]

Wow those headers made a huge difference. It sounds great.

[lo_jack]

Old thread, coming back up.

Could you not just take a set of headers with only 1 oxygen bung and weld one into the middle primary, like the OEM manifolds? The problem I see with putting an 02 sensor south of an aftermarket cat is you need 02 extensions. I guess that's a small thing but another point of potential failure.

I only just realized the OEM manifold is steel and not cast iron.

[Rookie48]

Following this and a few other threads on E53 3.0i headers... I'm at that juncture with my 2003 E53 X5 3.0i 5MT. I have almost 130,000 miles on the original cats. I do have a SuperSprint rear sections. The engine does have a mild OE tune on it.

Since the truck is getting older, not sure I want to install Turner $1700 headers on it, I think an eBay set will suffice to get a few more years of service out of it. Problem is - what are decent "eBay" headers? I don't mind spending a few hundred bucks for something decent. What about fitment for a X5? My indie shop will extend the headers since they need to install aftermarket cats anyway - I have to pass NJ emissions.

Any e53 3.0i owners out there purchase eBay headers and have any comments? I'm looking for recommendations....

Thanks in advance - xoutpost has been a wealth of information!

[Ricky Bobby]

From what I've read any decent set of E46 330? headers should work, around $100 - if you want, you can get them ceramic coated -

Your shop will have to install cats on them and extend them a couple inches to meet up with the downpipe/midpipe section but any good shop fabricating exhaust components should work and get you to pass -

[lo_jack]

The E46 people are all in a similar spot, unless they are hardcore racers. The cars are worth 7k at best, and a set of ebays are an improvement over most every OEM manifold barring a couple of exceptions. Those exceptions cost as much as new ebay cheapies on ebay as it is.

There are subtle differences in the ebay selection. None have 02 bungs in the OEM location for M54. But some have two bungs each. They are not remotely in the same position as OEM, so good luck on your CELs.

Some will need more extension than others. Most all have 1.75 primaries and oval collectors. As far as design goes, there are basically two types on ebay: one where the primaries merge way down by the transmission, and some where they merge nearly right off the head, closer to an M3 OEM tubular manifold design.

Those, by the way, would probably work (and maybe the Z3 manifolds as well), but there is some wonky air injection system on those that you have to block off. There are plates for that people sell, but it adds to the cost. Then there is the problem that they are a 3 bolt flange. If you wanted to bolt a cat to it there...great..but not useful if you wanted to put the cats later.

Some come with extra bits of pipe or clamps, but nearly all of the longtube kinds are just a pipe at the end, no flange. Some do include bolt together flanges, but not necessarily the 2 bolt kind that mates to the OEM midpipe.

Anyway, RB is right, you can get nearly all of them to "work," but there are some variables to look at that could make one better or worse for whatever you want to do, mostly hinging around cats. I think the only really important thing is to watch how many studs it takes to bolt them up and where they are located.

[tecboy99]

I installed eBay headers last year, and I absolutely love them. They are truly the way to go. Really any $100 M52/M54 headers will work. After I installed them, I Brought it to an exhaust shop to make the connection to the mid-pipe. They cut the original flanges off the mid pipe, and welded a new little section of pipe with a flange to make it work. As far as the 02's go. I just installed the pre-cat sensors. It doesn't matter which bung hole they go into, as long as they fit. I then flashed the car with the Euro 2 tune to remove the check engine light, delete the secondary air pump, and optimize for the headers. Bolt on and hold on! I haven't done any dunk testing but, it feels like a 10hp gain at least. The best $100 I've spent on the car.

[Ricky Bobby]

Jimmy how much did the shop charge you for install? Just curious - Either way I agree with you they really are the last bottleneck of power when doing engine tuning on the M54, being naturally aspirated - (short of adding a blower or turbine at least)

[Rookie48]

Techboy99:

Do you remember which manufacturer you got them from?

I will need to have post-CAT O2 bungs (aftermarket cats), but they can be extended and added ("J bungs, or regular) by the shop I use.