Quote:
Originally posted by RavingCivic
actually ur all wrong
4-2-1 or 4-1 doesnt make the top end or low end power. it has hardly anything to do with it. it has to do with ease of installation and weight
what makes the difference is length of the primaries and secondaries, how short or long the collector is at the end of the header, and how smooth the merges are.
the longer the primaries are, relative to the length of the secondaries the more low to mid range hp output will be
so if u want high rpm hp then go with something that has short primaries and longer secondaries,
if u want fairly equal increase across the dyno then get even length primaries and secondaries
the merge from the primaries to secondaries has to do with the restriction in air, so the smoother they are,the less backpressure u will get.
the length of the collector has to do with HP numbers as well
if it is short then it will aid in top end hp numbers, if it is slightly longer then there will be a boost in midrange hp output. it also has to do with velocity of air, meaning backpressure, the smoother it is then the less back pressure there is and better hp numbers ye shall receive.
iF ur car is lowered more than 1 1/2 inches do NOT get 4-1 header, *if it is box style* the 4-1 header has bends from the primaries that will cause ground clearance issues
hope this helps
i am still debating on which header to get
the bisimoto puts out 8-12 whp on stock motor but runs 600- 750 for the painted model, plus it has to be welded to fit to the exhaust.
the COMPTECH, Landspeed Powercore, and DC SPORTS header all give around 7 whp *as tested from SCC and import tuner magazine.
i like the JG EDelbrock model as well along with the 3 listed above. it has many great features
IMO the rest are kinda iffy. they all have there issues
i am awaiting emails from several off brand headers but i think they will be a joke anyways
i think for the 400-500 u spend on a header may be worth 7 whp
but then is 750 worth 12 whp?
Definetly get SS over Ceramic, u will have miscolortation *which IMO looks tight as shit, some exhausts do that as well*
ceramic rusts to damn much.
again i hope this helps
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Well that is as backwards as I have heard it.. maybe imports are different like I said before, but airflow is airflow.. Longer primaries should be for high end power (look at topfuel dragsters and see how long their primaries are.. and they operate in the 7500-10000 rpm range). A little more backpressure with give you more low end tq (4-2-1) while less with give you more high end (4-1). This concept is a 40 year old concept.
And a ceramic header if coated properly will not rust.. if the product is garbage I wouldn't buy it anyways...