M50 exhaust manifolds on E53 M54 head

[lo_jack]

Has anyone physically checked a set of M50 manifolds on an M54 head?

I know some people were looking on the ebay for header options. I'd like to use those shorty cast iron M50 manifolds with 02 bungs in them like our M54 steel manifolds.

Of course they will not bolt up to the rest of the exhaust.

But they do not have cats on them and they are cast iron. I'll make the rest. And yes, I will run cats.

[Green Dragon]

Hey buddy, m50 manifolds should bolt right up to the head with no problem. I had my OE 325i e36 cast iron manifolds coated. They were okay but I would look at some s50/s52 manifolds as well as they may offer better flow/performance. Either way, they will flow way better than what we have right now. Not sure about clearances with the engine mount and front drive shaft, etc. You could build a nice setup pretty cheap. I'm putting my schmiedmann Alpina replicas on this weekend.

Here's an option as well you could look into. I almost pulled the trigger on these. They would make a great set of headers and would making connecting to the rest of the exhaust a breeze with that flange after the collectors. 4pc Performance Exhaust Manifold Headers Fits BMW E46 E39 Z3 2 5L 2 8L 3 0L L6 | eBay

[lo_jack]

Thanks! One can always count on the Dragon to have torn something apart and put it back together better.

[Bmwe5320023.0]

I'm thinking of doing this mod.
It seems pretty popular among e46 guys, but I don't see it much at all on this forum


Here's a kit i found

https://www.seemslegitgarage.com/pro...ld-adapter-kit

https://www.seemslegitgarage.com/pos...5_uHnnadZMh2Ym

[BimmerBreaker]

I don't think the M50 manifold conversion really adds any power - the only dynos you'll see are either from people who sell swap kits, or people who compared a stock engine/stock tune to m50 manifold/upgraded tune. You can pick up a few hp on a stock tune too, and if you compare a tuned stock manifold car to a m50 manifold car I doubt you'd see a real difference.

The M50 manifold doesn't even flow that much more area than the M54 manifold, to run an M50 you plug the secondary runners than have to port out the main ports by a volume that pretty much equals the plugged ports. And the M54 manifold benefits from the DISA system which you lose with that M50 manifold.

Yes, there are a lot of people who have done that swap and claim big gains and this or that, but there are a lot of people who will say or do anything to try to just justify the time spent on their mods; and many dyno operators willing to adjust a correction factor to put a smile on their client's face. Ultimately, there are many products marketed to enthusiasts simply because they are marketable - not because they actually offer any real benefit.


With that being said, this thread is about exhaust manifolds, not the intake manifold. M50 exhaust manifold do bolt up to the M54 head.