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Discussion Starter · #1 ·
Due to the number of threads that have been started regarding a specific header design, then hijacked by someone extolling the benefits of some other design, then had posts deleted, I thought I'd start a thread inviting the various header vendors, and any one else of course, to compare their headers!

I would ask in advance that, unless a post breaks the forum rules by being abusive etc., that no posts are deleted or modified. If you wish to modify your own post, please clearly marked the edit and if possible leave the original post visible. Please post all relevant modifications, cats, maps, etc. when quoting performance figures.

In an ideal world all the headers would be tested on the same car at the same time on the same dyno, in the real world this is impossible. Even testing the same car with different headers would not give a 100% accurate comparison due to changes in atmospheric conditions between tests as swapping headers over will take the best part of a day.

We're all grown up here, at least I'd like to think so, so please do not post inflammatory or derisory comments.

Generically and theoretically, 4-1 headers should perform better at high rpm, peak power being delivered at the maximum rpm even with a raised limiter. 4-2-1 headers should perform better at lower rpm, usually with a slight drop in performance at the very top end, peak power being delivered at slightly under maximum rpm. I believe the often quoted characteristic that 4-1 headers will have dip in power at lower rpms is relative to a 4-2-1 design and not the stock headers, at worst the 4-1 design should be similar to the stock headers.

The main discussions appear to revolve around the following headers, in alphabetical order :

Dinan

Equal length 4-2-1, firing sequence maintained.

Evolve

Equal length, 4-2-1, firing sequence not maintained.

OEM

Not equal length, sort of 4-2-1 but asymmetrical, firing sequence sort of maintained.

SuperSprint

Non Equal length 4-1.

Van Manen Original

Non Equal length 4-1.

Van Manen Varient II

Equal length? 4-1.

Of course there are others, discussions on those are also welcome.
 

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what does that mean - firing sequence maintained?
are you referring to pulsing? pairing relevant cylinders when designing the manifold?
 

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Discussion Starter · #3 ·
what does that mean - firing sequence maintained?
are you referring to pulsing? pairing relevant cylinders when designing the manifold?
Correct.

With a 4-2-1 design maximum performance is obtained when the primary pairs are matched with the cylinder firing order. With a V8 this is dificult to achieve on one of the banks without very complex primary shapes, which is why the Dinan headers are so expensive.
 

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Richard - this is a great start in summarizing the current state of headers for the E39 M5.

Would it be possible to put the the global availability and any relevant links for these headers? For instance, Evolve & VM seem to only be available in Europe right now, and I believe only for RHD cars on a mass basis. This would be helpful for prospective buyers (like myself!).
 

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looking at the above, if you wanted a 4-1 header you'd go van manen
if you want a 4-2-1 you'd go dinan if cost no issue, or the Value For Money option: evolve.


i take it on a 4-1 equal length header design, sequential firing is not an issue?

but which is better 4-1 or 4-2-1; horses for courses.

interesting dinan went for a 4-2-1 for their supercharged cars as well as NA cars - ?because they did not want to research the 4-1 option for their SC conversion ?cost an issue- 4-2-1 being an all rounder?
 

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It might be good to list the approx RRP as well?
For some people this might be a major factor.
 

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sounds like a never ending comparison.... Im just happy to have one of those brands :)
 

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LHD Evolve 4-2-1 maintain firing order.
So this is what you guys have been up to with the LHD headers? Can you elaborate on how this is being accomplished?
 

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Just going by design and firing order alone it seems that Dinan has the best option for sure.

Anyone have graphs to prove the best numbers?
 
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Haha cost to value please? and availability in the US?
 

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4-1, firing order and equal length (on the same collector) arent important.
Absolutely correct :applause: :biggrin:

I have been having a lot of discussions about these aspects whilst my manifolds are being fitted and feel that I have learnt a lot and it has all been very interesting.

cheers
 

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I love my Evolve headers and full system :flag: - the best mod you can do to the M5.

I just wanna thank all the companies that believe in the e39 M5 enough to make performance headers in the first place.
 
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