S54 Header Design talk

[Bry5on]

Another thought I want to look into: I think with longer runners we also get more latitude to place the merges in line with each other and can make the section 1/collector length equal without needing to resort to a funky bent section 1 design. its going to come down to packaging.

Also at least on the S52 those Kromer Kraft headers sound pretty awesome: https://www.youtube.com/watch?v=S4JdnVzNv0Y

I agree and think this is where 3D printing will come into its own. Back two is likely to need to sweep up/forward a little and packaging with tubes is probably too tight. True equal length is going to be key. Then maybe we can boost/attenuate a natural resonant frequency or two downstream to make it more Ferrari and less BMW

[SQ13]

Dammit I just spent $5500 on a full Supersprint V1 setup 😭😭😭

[George Hill]

Another thought I want to look into: I think with longer runners we also get more latitude to place the merges in line with each other and can make the section 1/collector length equal without needing to resort to a funky bent section 1 design. its going to come down to packaging.

Also at least on the S52 those Kromer Kraft headers sound pretty awesome: https://www.youtube.com/watch?v=S4JdnVzNv0Y

The video I posted above is the KKs on my car a few years back.

I know where there is a set of S52/E36 KKs and I am trying to buy them too, lol.

I do think that an aftermarket RH engine support arm that is much thinner will help with exhaust design and packaging too.

[Tbonem3]

Dammit I just spent $5500 on a full Supersprint V1 setup 😭😭😭

You're fine. They're the best around, and don't be surprised if they're still the best around in another 5 years.

And no header thread is complete without the greatest video ever: (I think it was confirmed by owner to be Kromer Kraft)

https://www.youtube.com/watch?v=6jRxtmi61aI

[3staxontheradio]

I do think that an aftermarket RH engine support arm that is much thinner will help with exhaust design and packaging too.

Sounds like another good application for a DMLS part.

[George Hill]

Likely, its pretty simple though, this is what we made for my setup. Made a jig using the original arm and then replicated it with tube and plate.







Also found another video of KKs on the dyno.

I know you aren't primarily going after sound, but I think the combo of equal length runners and the megaphone off the 2-1 are a big part of it. I do expect you'll continue the dual much further back than the KK merge after the collectors.

https://youtu.be/mLs6hziC6is?si=7VyUk_HWoiZgOzZJ

[digger]

to play the devils advocate, there are diminishing returns with the exhaust primary on a nearly stock engine once you've removed the catted manifold. This should be looked at from the perspective that nice headers look cool and modern manufacturing techniques are fun to play with.
If you go into this with the thought that there are significant power gains to be had over existing products you'll be disappointed

[3staxontheradio]

Hello from the other forum.

As I said there- I was just going to put a set of supersprint v1s on it but they are pricey and I jump at just about any chance to convince myself I can do it better for cheaper. It's always a learning experience, usually it is better (or at least more specific to what I want), rarely does it end up actually being cheaper. Also when I look closely at photos of the supersprints I think the runners are a lot shorter than the kromer kraft and pipemax are putting out. Maybe that an illusion, I really want to measure one.
Also I have stock cams now but don't plan to keep stock cams forever. CSL airbox and cams in my not too distant future.

[digger]

Hello from the other forum.

As I said there- I was just going to put a set of supersprint v1s on it but they are pricey and I jump at just about any chance to convince myself I can do it better for cheaper. It's always a learning experience, usually it is better (or at least more specific to what I want), rarely does it end up actually being cheaper. Also when I look closely at photos of the supersprints I think the runners are a lot shorter than the kromer kraft and pipemax are putting out. Maybe that an illusion, I really want to measure one.
Also I have stock cams now but don't plan to keep stock cams forever. CSL airbox and cams in my not too distant future.

you should be using pipemax for your intended end goal as the power and rpm predictions etc obviously affect pipe size and length

you should be able to estimate the SSV1 lengths on photo as you know the header flange inlets are pitched at 91mm so you can scale somewhat reasonable with the right photo

[3staxontheradio]

you should be using pipemax for your intended end goal as the power and rpm predictions etc obviously affect pipe size and length

you should be able to estimate the SSV1 lengths on photo as you know the header flange inlets are pitched at 91mm so you can scale somewhat reasonable with the right photo

Yeah that's why I'm using pipemax. Im not going to build a header for one application and then blindly apply it to another. I had two config files going initially just to see how increasing VE and changing cam specs altered the proportions. I haven't been updating the other file since I keep changing the config on the stock cams file and I'm still not confident it's configured correctly. I'm also early in this process, I won't be building anything for quite a while, and am not going to build anything without a more complete understanding of what it will do.

[JakeM346]

I don’t believe there is much more to be found exhaust performance wise with the e46 m3.
especially since bmw produced the extra lighter exhaust for the CSL but didn’t change the shape. Basically telling me that the most limiting factor will probably be the catalytic converters and the rear silencer down the line.
Probably you’d have to increase rpm even further and remove the cats as well as the end muffler to really get a true benefit from an even more optimized header design. Keep in mind the end muffler is the real looser of power for the na engines and the m3 one is already very optimized which is why it’s so big.

Don’t know if I can post this look next Chat for the link to official exhaust documentation

[JakeM346]

https://www.unofficialbmw.com/images/BMW_M3_Exhaust_System.pdf

[digger]

Yeah that's why I'm using pipemax. Im not going to build a header for one application and then blindly apply it to another. I had two config files going initially just to see how increasing VE and changing cam specs altered the proportions. I haven't been updating the other file since I keep changing the config on the stock cams file and I'm still not confident it's configured correctly. I'm also early in this process, I won't be building anything for quite a while, and am not going to build anything without a more complete understanding of what it will do.

Probably only way to see what affects what without testing is a 1D simulator (E.g. Engmod4T, etc) as pipemax is not a simulator

[Bry5on]

Even if it doesn’t make much power over a supersprint v1 setup, at least it’ll be equal length so that none of the damn cylinders will be running lean while the others are running rich. 🤑

A longer tube header is more expensive to produce and deal with for an OEM, no way around that. Thinning walls is cheap to do in the same tooling. The CSL exhaust has compromises, just like anything else.

I’m sure there is power to be gained, the question is how much and who believes it’s worth it. The math seems to point to not being fully optimized as-is. And I trust math.

Personally I’m chasing the equal length header sound and also can’t let my engineer brain leave optimization on the table. I don’t care for 5hp but I do enjoy the process of extracting it. And remember, this car is far from perfectly engineered!

[JakeM346]

Even if it doesn’t make much power over a supersprint v1 setup, at least it’ll be equal length so that none of the damn cylinders will be running lean while the others are running rich. 🤑

A longer tube header is more expensive to produce and deal with for an OEM, no way around that. Thinning walls is cheap to do in the same tooling. The CSL exhaust has compromises, just like anything else.

I’m sure there is power to be gained, the question is how much and who believes it’s worth it. The math seems to point to not being fully optimized as-is. And I trust math.

Personally I’m chasing the equal length header sound and also can’t let my engineer brain leave optimization on the table. I don’t care for 5hp but I do enjoy the process of extracting it. And remember, this car is far from perfectly engineered!

Yeah I’m mainly stating that you’re unlikely to gain something because you’ll be limited by the muffler