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Thread: 4-1 Headers talk!!

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Posts: 91-100 of 103
2012-09-20 19:25:56
#91
i would like to make one if i had a test car
Last edited by S@nt0s on 2012-09-20 at 19-26-53.
2012-09-20 20:26:42
#92
I have the winner of this great battle for sell....

http://www.sr20-forum.com/naturally-aspirated/57448-fs-aebs-4-1-header.html
Last edited by LerkZone on 2012-09-20 at 20-27-40.
2012-09-20 20:37:35
#93
it's for sell! holy shit.
2012-09-21 07:41:04
#94
Thats a great article. I think the ssac header (latest one out) makes more power than all of those though if im not mistaken. It would be cool to do a simple test of bolt on power headers with all the new school headers and custom headers people have made. No tuning, just bolt on power like the old days.
2012-09-21 09:52:15
#95
IS it just me or is the pacesetter in the first pic a 4-1 and in the second pic it's a 4-2-1.

Also, I wonder how much better that AEBS would have done if it had a better firing order arrangement at the 4-1 merge.
2012-09-22 15:36:17
#96
Originally Posted by ashtonsser
Thats a great article. I think the ssac header (latest one out) makes more power than all of those though if im not mistaken. It would be cool to do a simple test of bolt on power headers with all the new school headers and custom headers people have made. No tuning, just bolt on power like the old days.


can u get a true ideas from this type a test. i know some mods u have to tune it for it to come alive and show its true capabilities....
2012-09-22 15:52:17
#97
Originally Posted by THOR

can u get a true ideas from this type a test. i know some mods u have to tune it for it to come alive and show its true capabilities....


Technically a correctly designed header will simply improve the engines volumetric efficiency by ensuring the blowdown (exhaust) process is as close to %100 complete as possible. The rest of the engine will not have an affect on if it helps or not.

However. Any other restriction throughout the intake filter, throttle body, intake plenum, intake runners, inlet ports, valves (int/exh), back through the exhaust ports and also after the collector, can negatively affect the engines volumetric efficiency. Therefore yes, it makes it hard to see the gains, especially since these headers are not matched to the engines head in most cases and are not tuned for the correct RPM at all. They still make power over stock though because they will flow better with less restriction (all are larger). However too large can be detrimental because you begin to loose the wave tuning affects that are not present in these anyway. Also the increased interior surface area causes greater heat transfer from the exhaust gas which we don't want either.

Walker
2012-09-22 16:39:44
#98
Originally Posted by Doctor
IS it just me or is the pacesetter in the first pic a 4-1 and in the second pic it's a 4-2-1.

Also, I wonder how much better that AEBS would have done if it had a better firing order arrangement at the 4-1 merge.


thts what i see too...
2012-09-22 19:18:14
#99
it's a 4-2-1 in all pics?

2012-09-22 19:57:04
#100
Originally Posted by Dudeman258
Originally Posted by THOR

can u get a true ideas from this type a test. i know some mods u have to tune it for it to come alive and show its true capabilities....


Technically a correctly designed header will simply improve the engines volumetric efficiency by ensuring the blowdown (exhaust) process is as close to %100 complete as possible. The rest of the engine will not have an affect on if it helps or not.

However. Any other restriction throughout the intake filter, throttle body, intake plenum, intake runners, inlet ports, valves (int/exh), back through the exhaust ports and also after the collector, can negatively affect the engines volumetric efficiency. Therefore yes, it makes it hard to see the gains, especially since these headers are not matched to the engines head in most cases and are not tuned for the correct RPM at all. They still make power over stock though because they will flow better with less restriction (all are larger). However too large can be detrimental because you begin to loose the wave tuning affects that are not present in these anyway. Also the increased interior surface area causes greater heat transfer from the exhaust gas which we don't want either.

Walker


Last edited by THOR on 2012-09-22 at 19-57-31.
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