S54 Swap Header Feeler

[MyE30]

ahh, indeed i will have to educate myself further.

from face value, looking at the factory header variants for the s54 and euro s50 it seems the engineers were attempting to get the tubes close to the same length. or were they more focused on the primary length in the euro s50 example? they surely didn't design them that way to make packaging easier. if so, why didn't they just make them the same as the US m/s5x headers/manifolds?

i understand that the term "equal length" in the literal sense means exactly that; maybe getting the primaries close to the same length would be a better question to ask the OP. i was just wondering because the #1 primary seems like more than a 4 inch difference compared to the #3 in the picture above.

like you said...need to do some more research.

[Cristov9000]

ahh, indeed i will have to educate myself further.

from face value, looking at the factory header variants for the s54 and euro s50 it seems the engineers were attempting to get the tubes close to the same length. or were they more focused on the primary length in the euro s50 example? they surely didn't design them that way to make packaging easier. if so, why didn't they just make them the same as the US m/s5x headers/manifolds?

i understand that the term "equal length" in the literal sense means exactly that; maybe getting the primaries close to the same length would be a better question to ask the OP. i was just wondering because the #1 primary seems like more than a 4 inch difference compared to the #3 in the picture above.

like you said...need to do some more research.

Like Nando said primary length and diameter, the merge collector (lenth and diameter) are most important. However, once you determine the primary length for the rpm you are tuning at you want all the primaries that length... hence equal length. Its not the fact that they are equal it is that they are all tuned for the same rpm.

Having everything tuned for the same rpm, not just primaries but cams and intake runners too, produces more max power but makes the power curve peaky. Having slightly different length primaries would tune their respective cylinders for a different RPM which broadens the power band but reduces your peak power. Hence engines that have "secondary" intake runners open up at higher rpm to retune the intake runner lengths, this kinda allows a wider powerband without completely sacrificing peak power.

With primary lengths there is a specific length (and harmonics of it)that will cause the reflected negative pressure wave to arrive at the exhaust valve right before it closes sucking the last bit of exhaust out of the cylinder and sucking in some intake gases. This is good and increases VE and ultimately power. If the tuned length is wrong this negative pressure wave to smack into a closed valve and not do anything or worse the subsequent reflected high pressure wave could arrive at the open valve push exhaust gas back into the cylinder.

SO while saying being equal length doesn't matter is true, having all the primary lengths at the same tuned length does... or at least knowing that the length of the primary is going to increase power around where you want your peak power to be and not hamper it. Making headers flow well while maintaining exhaust gas velocity is only one design consideration for a header.

[TinyT]

This is a really nice looking set of headers. It looks like the design is geared more toward fitment than performance. Have you considered designing headers that have equal length runners? You definitely have the skill to pull it off and the end product would be well worth the money, IMO.

Thank you!

I will be offering several different sets in the future. I have been too busy to even do a release on these because I haven't been able to build any inventory. I will keep everyone posted on my plans.