Euro Headers

[M-technik-3]

http://forums.bimmerforums.com/forum/showthread.php?t=1455833

Here is a set of EU S50B32 headers for sale on my local BFc board. Seller is reputable in our area.

[Gnarles]

My setup is similar. Obd2 manifolds, obd1 mid section, m3 muffler. It does sound nice but probably is pretty restrictive.

[hoveringuy]

yeah I bet that torque is nice! What mid section and muffler are you running?

Stock OBD2 M3. Nothing special. It is quiet and it sounds nice.

[Gnarles]

When I first installed the headers I was slightly disappointed. They sounded about the same and didn't feel faster.

The story here is the power I picked up in the hour I was at the dyno. I went from 208 to 216 by adding some fuel and by retarding the exhaust I gained all that low end torque, which I really felt on the drive home!

The M54 is a little bit choked by small exhaust ports. Disappointing that it dies after 6000. ZHP cams or Shrick cams would fix that. The larger 69mm M54 TB will help, too. As would a new muffler....

Still, 218hp is easily S50 territory.

yeah I bet that torque is nice! What mid section and muffler are you running?

[sonnyqm3]

i have a set available if anyone is interested...

[hoveringuy]

Good info! It's suprising that you gained quite a bit of low end torque. I would have thought your gains would have been more on the top end with the euro headers. What does the butt dyno tell you? Can you feel a big difference over the obd2 manifolds?

When I first installed the headers I was slightly disappointed. They sounded about the same and didn't feel faster.

The story here is the power I picked up in the hour I was at the dyno. I went from 208 to 216 by adding some fuel and by retarding the exhaust I gained all that low end torque, which I really felt on the drive home!

The M54 is a little bit choked by small exhaust ports. Disappointing that it dies after 6000. ZHP cams or Shrick cams would fix that. The larger 69mm M54 TB will help, too. As would a new muffler....

Still, 218hp is easily S50 territory.

[Gnarles]

Good info! It's suprising that you gained quite a bit of low end torque. I would have thought your gains would have been more on the top end with the euro headers. What does the butt dyno tell you? Can you feel a big difference over the obd2 manifolds?

[hoveringuy]

header dyno comparison

This is euro headers vs OBD2 exhaust manifold, same exact tune. I actually lose a few horsepower. Could easily be difference in tire pressure, how the car was strapped-down, etc.



The good news is that the headers responded very nicely to tuning. They allowed me to retard the exhaust cam signficantly and they liked more fuel. Gains from around 2500 to 3500 are nice. OBD2 manifolds didn't like retarding the exhaust AT ALL!

Lesson here is that headers need a header tune to take full advantage.

[hoveringuy]

Tentative results from datalogging the MAF flow before and after the euro headers are that I have a slight bump in voltage. I went from around 4.25v at 6000rpm to 4.35v. I'll need to do a bunch of statistical analysis next week by combining multiple runs to get more accurate figures.

The MAF starts getting less linear at higher flows, so even a tiny bump in voltage correlates to a huge increase in flow.

[Adrian_Visser]

Has anyone else had serious problems with the hole alignment on the racelands?

The holes in the flange for mine didn't line up worth a fuck.

Even after drilling them out the next two drill sizes (11/32 which is actually the same as the OE header flange holes) I still had to hog the holes out a little more with a carbide burr.

Godamn that is some hard stainless too I went through many cobalt bits before buying snap on ones that did the job.

And this is all without the engine even going into the car yet lol. I can't wait.

[hoveringuy]

why is it in the trunk? you're missing out on half the scavenging benefit from a decent header. :p

I'm kidding. The X-pipe is part of the OBD2 cat.

My long-term plan is that I'll build a new center section where there will be a X-pipe right after the V-band clamp or just a 2 into 1 merge.

[nando]

why is it in the trunk? you're missing out on half the scavenging benefit from a decent header. :p

[hoveringuy]

where's your X pipe?

It's in the trunk. No... it's incorporated into the OBD2 cat section.

We did some flow testing on several different types of headers, including the ones made for the m50/s52 engine swap. We found that the factory m3 exhaust manifold flowed just as good as most and better than some.

I don't think flow testing tells the whole story.

I logged my MAF flow with the OBD2 headers. I will log again and more flow throught the MAF = WIN!

[nando]

We did some flow testing on several different types of headers, including the ones made for the m50/s52 engine swap. We found that the factory m3 exhaust manifold flowed just as good as most and better than some.

what kind of flow testing? a static test like you use on an intake port isn't going to tell you much. headers are far more complex..

[gman325is]

We did some flow testing on several different types of headers, including the ones made for the m50/s52 engine swap. We found that the factory m3 exhaust manifold flowed just as good as most and better than some.