[e90yyc]

Just wondering if there’s and difference in fitment between 325, 328, 330, as well as xDrive vs. RWD variants.

From what I understand there isn’t, but just wanted to confirm.

Thx!

[Serf27]

They have different part numbers but they should be the same in terms of functionality.
Mounting wise, they are the same, including SULEV.
There is a difference from rwd/xi and lhd/rhd.

[Efthreeoh]

The 330 was different from the 325. Better flow to compliment the 3-stage intake.

[e90yyc]

Originally Posted by Serf27

They have different part numbers but they should be the same in terms of functionality.
Mounting wise, they are the same, including SULEV.
There is a difference from rwd/xi and lhd/rhd.

You said they’re the same but xi and RWD are different?

Originally Posted by Efthreeoh

The 330 was different from the 325. Better flow to compliment the 3-stage intake.

Ah interesting!

Okay thanks guys. I noticed aftermarket header options all seemed to have common fitment across E9x models (and E82/88 I believe).

But then I noticed part numbers differed on RealOEM.

That all makes sense.

[3PedalJake]

RealOEM shows me the same PN for 325i and 330i, but different for the 328i, so I wonder if it was changed for the N52k for some reason. I'm sure they will all bolt up but there must be some difference.

https://www.realoem.com/bmw/enUS/sho...diagId=18_0587

https://www.realoem.com/bmw/enUS/sho...diagId=18_0587

https://www.realoem.com/bmw/enUS/sho...diagId=18_0587

[e90yyc]

Originally Posted by 3PedalJake

RealOEM shows me the same PN for 325i and 330i, but different for the 328i, so I wonder if it was changed for the N52k for some reason. I'm sure they will all bolt up but there must be some difference.

https://www.realoem.com/bmw/enUS/sho...diagId=18_0587

https://www.realoem.com/bmw/enUS/sho...diagId=18_0587

https://www.realoem.com/bmw/enUS/sho...diagId=18_0587

Thanks!

Sorry—I should have been clearer upfront: My concern is limited to the compatibility of aftermarket options. It sounds like while BMW might have different PNs and even slightly different designs, when it comes to aFE or AA for instance, they’ve got just one product for the whole N52 E9x range.

I’ve ordered some headers, but panicked after I realized the product description didn’t explicitly mention the 328. Will post about them once they’re here.

[3PedalJake]

Originally Posted by e90yyc

Thanks!

Sorry—I should have been clearer upfront: My concern is limited to the compatibility of aftermarket options. It sounds like while BMW might have different PNs and even slightly different designs, when it comes to aFE or AA for instance, they’ve got just one product for the whole N52 E9x range.

I’ve ordered some headers, but panicked after I realized the product description didn’t explicitly mention the 328. Will post about them once they’re here.

Right, I knew what you were getting at that's why I said they all bolt up IE they have the same external physical dimensions. I had assumed they were all the same part # until this thread.

[Serf27]

I meant the shape on rwd models are the same from 325-330.
The mounting points should also be the same between rwd and xi but xi has a different shape/length for the awd system.

[e90yyc]

Originally Posted by Serf27

I meant the shape on rwd models are the same from 325-330.
The mounting points should also be the same between rwd and xi but xi has a different shape/length for the awd system.

Sorry—not sure why I’m still not getting this. I’m just gonna break it down into individual points to confirm:

1. Mounting points at the block and the midpipe are the same for all E9x
2. The actual shape of the headers differs between RWD and xDrive due to clearance issues
3. xDrive headers are therefore (likely) compatible with RWD cars, but RWD headers are not compatible with xDrive not because of the mounting points, but because of the shape of the manifold itself

So, when it comes to aftermarket headers, they’re shaped in order to permit installation on both RWD and xDrive cars.

Am I getting this lol?

[Serf27]

I looked at some eBay vendors.
They’re listing the same headers for both Rwd and awd. I guess they’re the same.
I pulled some rwd and awd headers off a couple of minutes hrs ago. I should’ve snapped some pics!

The rwd was a lot easier to get out than the awd.
With either one, reinstalling is a task I would not want to do.

[e90yyc]

Originally Posted by Serf27

I looked at some eBay vendors.
They’re listing the same headers for both Rwd and awd. I guess they’re the same.
I pulled some rwd and awd headers off a couple of minutes hrs ago. I should’ve snapped some pics!

The rwd was a lot easier to get out than the awd.
With either one, reinstalling is a task I would not want to do.

Okay gotcha.

Indeed, the origin of my confusion was the seemingly universal application of the aftermarket products (AA, aFE, no-names), but the very limited application for each original PN.

In my case, my sole concern was making sure the headers I ordered will fit, but then of course my curiosity kicked in.

With AWD the subframe is such a bitch to work around. I don’t look forward to doing this job, but I do look forward to being done it.

Thanks!

[Serf27]

Originally Posted by e90yyc

Okay gotcha.

Indeed, the origin of my confusion was the seemingly universal application of the aftermarket products (AA, aFE, no-names), but the very limited application for each original PN.

In my case, my sole concern was making sure the headers I ordered will fit, but then of course my curiosity kicked in.

With AWD the subframe is such a bitch to work around. I don’t look forward to doing this job, but I do look forward to being done it.

Thanks!

Yea, I looked at 2 vendors selling aftermarket ones and both had xi and i listed for fitment.
Maybe the OEM part numbers change because different material is used for the catalytic converter…

The rear nuts on the rear manifolds where nearly impossible to see. I was just feeling around for the nut and guiding the air ratchet to it.

The xi subframe was the biggest issue.
I think 1 manifold came out but the other one didn’t want to.
It was getting stuck on this bar that goes across the subframe. I cut the bar and bent it out of the way to get the manifold out, haha.

Good luck!

[The Nightman]

Only difference I'm aware of is RHD vs LHD

[e90yyc]

Originally Posted by Guy Fieri

Only difference I'm aware of is RHD vs LHD

Ding ding ding. I think we have a winner.

Makes me wonder what the technical differences between the BMW PNs are, but between when I first posted this and now, I’ve come to this same conclusion. They all fit—even 1 series and some X5s even??—but the only physical limitation is RHD/LHD.

Thanks everyone for helping me understand this.

[e90yyc]

Originally Posted by Serf27

Yea, I looked at 2 vendors selling aftermarket ones and both had xi and i listed for fitment.
Maybe the OEM part numbers change because different material is used for the catalytic converter…

The rear nuts on the rear manifolds where nearly impossible to see. I was just feeling around for the nut and guiding the air ratchet to it.

The xi subframe was the biggest issue.
I think 1 manifold came out but the other one didn’t want to.
It was getting stuck on this bar that goes across the subframe. I cut the bar and bent it out of the way to get the manifold out, haha.

Good luck!

Lol I take it you’re flipping cats?

Did you go at them from inside the engine bay with the coolant expansion tank removed? I’m hoping access isn’t too terrible but I suspect it will be…

[Serf27]

Originally Posted by e90yyc

Lol I take it you’re flipping cats?

Did you go at them from inside the engine bay with the coolant expansion tank removed? I’m hoping access isn’t too terrible but I suspect it will be…

Haha, no. You would need to find cats to buy like 1 or 2x a day to make some good money and get them at a low price. For all 8 cats (4 headers and 4 secondary cats) I got $1340.
These were just 2 parts cars that were pretty much done.

I did most of it from the top of engine bay. Some manifold bolts I had to get from the bottom of the car.

The coolant tank was already removed. So that does make it easier.
I remember an ac line bolted to the AC compressor either being in the way of a manifold nut or making it hard to access the nut, so I unbolted that line.

Unbolting them from the rest of the exhaust on the bottom was easy.
Removing the nuts from the front manifold(near radiator) wasn’t too bad. I don’t think it will be hard for you to put those nuts back on and torque them.

Rear manifold, the forward nuts are still accessible. The rear nuts near the firewall were the ones I just felt around with my fingers to find. This is the point at which I said “I would hate to have to reinstall these nuts”.

I used these tools. Different lengths for different nuts that required more or less space.
3/8” ratchet and flex head ratchet
1-3/4” wobble extension
Universal socket adapter/swivel adapter
11mm socket
Deep 11mm socket.
Air ratchet to make quick work of spinning the nuts off.

The subframe brace/bar is the only one I don’t know much on, since I cut it. Maybe if you loosen the right side of the subframe so it drops down a little, the manifold can clear the firewall and subframe.

[e90yyc]

Serf27 Thanks! That’ll definitely help. I do have an electric ratchet which should help, but I’m sure it’ll still be awkward as hell.

I’d imagine once I’ve got them off it’ll be easier to see things? I’m planning on replacing all the studs, so I really hope I can see .

[Serf27]

The electric ratchet will definitely help with the rear bolts where a ratchet Barry has enough space to turn 1/8” at a time.
The AC line I removed was the top one. Hopefully it isn’t an issue for you.
I still have the XI here, so I took a photo of it.
Plenty of room to change the studs with the manifold removed.

[e90yyc]

Serf27 I started removing nuts last night just to see what I’m in for. Happy to say I was able to remove the ones around the AC hard line and the ones at the back near the firewall with relative ease. For the nuts around the AC line, I was able to seat the socket/extension by hand, and then pop the ratchet on..

Having just the right length deep socket/extension combo made all the difference. Shorter and I wouldn’t have cleared manifold with my ratchet; longer and the ratchet would have been pinned up against the body and unable to turn. I broke them loose by hand and then zipped them off with the electric ratchet. Would highly recommend the tool. The extended-reach head has come in handy more times than I can count.

There might still be some surprises lurking but I feel pretty good about it. I’ll finish the job on Tuesday when they arrive.

[Serf27]

Nice! Once they’re all of the manifold, I used a pry tool to slightly pop them off and then they’re loose and ready come out.

[e90yyc]

Thanks man I appreciate the help and the pics!!