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Discussion Starter · #1 ·
hey.. I will appreciate if you guys could tell me which headers I should get !! I know there is DC-S ,Alpha werks, Magen,I also noticed they're 2 typs; 4-1 and 4-2-1... I have K&N cold air intake and TWM short shifter, I'm also planing to get the S pipe and cat back exsaust... so any feed back?? thanks
 

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If your looking for best performance... Probably should go with Alphawerks, it is just a little bit better in terms of gains by small margin and if you want something that also looks good in your engine bay. A lot of people running w/headers can attest to this modification as probably one of the best and when combined w/an S-Pipe, and Full Exhaust system you've got yourself some N/A power.
 

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It's also the only mod that is a Federal violation, and is illegal in all 50 states.
 

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It is an I-4 engine. Speaking of which, are there ever any block 4 engines, like 2 and 2? Isn't it implied that if it's a 4 cylinder engine, that it's in-line?
 

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Ironhead
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ive never seen 4 cyl car that wasnt inline.

honda used a V4 engine in their bikes.
 

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Discussion Starter · #9 ·
Hey guys.. thanks for all ur feed backs, but I'm still confuced regarding 4-1 or 4-2-1 headers... which one is better as far as street racing!!! ?? I will get the S pipe along with the headers for sure..
 

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4-2-1. Better midrange power than a straight 4-1.
 

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Originally posted by PhamKL@Dec 28 2005, 05:49 PM
For 4-2-1 vs 4-1: having a 4-2-1 design creates two points in which flow is maximized. In an exagerrated dyno, it should be possible to observe two small torque peaks. This results in a low end peak and a upper mid range peak which results in better power and sooner. A 4-1 only has one peak.

This is highly simplified but the longer the runners, the higher and later the peak occurs.
I don't know where you got this info, but it's a little bit inaccurate. Longer primary tubes tend to produce more low end torque. Shorter primary tubes tend to produce more high end torque. It's pretty much the same with primary tube diameter. Larger diameter makes more high end torque (higher maximum flow rate) and smaller tubes make more low end torque (better energy retention for a variety of reasons, but not capable of higher flows). We won't even start to discuss reversion, anti-reversion, and auxiliary chambers. There are a number of software programs available on the web that address the design issues and do all the calculations for you.

4 - 2 - 1 works better for street and roadrace applications except on very high speed tracks like Willow Springs. It does this by tying the two cylinders that are 360 degrees out of phase together before merging the flows into the second collector. The reason for this is to improve scavenging in the cylinder pairs that are working like parallel twins in the middle rpm range. 4 - 2 - 1 pipes excel in midrange performance and help raise the middle part of the torque curve.

4 -1 works best for drag racing because it produces the best peak numbers. Since drag racing is what it is, the best peak number with the best gearing will win almost without fail (until you get to the truly exotic classes where the clutch has more to do with winning than anything). There are also huge arguments about which way to pair the cylinders in the collector since some guys want to put the pairs side by side, and other guys think they should be across from each other. Regardless of the details, a 4 - 1 exhaust header will make the best maximum torque at high rpm at the expense of low rpm torque. This is why I would choose a 4 - 2 - 1 for a street engine.
 

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Ironhead
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as always, thanks for posting solid info, lo bux.
 

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Originally posted by inevitablegod@Dec 26 2005, 10:22 AM
ive never seen 4 cyl car that wasnt inline.

honda used a V4 engine in their bikes.
Flat-four (aka horizontally opposed four-cylinder) engines are used in all 2.0 and 2.5 liter, four-cylinder Imprezas and Legacies sold in the United States.

-Ed
 

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Whats up Sheriff, its Guillermo, like I told you over the phone the AW header seems to give the better gains and with an s-pipe it'll feel even better, good luck man
. I'm very happy with my set-up thou, Megan header, ZPI s-pipe and Injen cold air intake.
 

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Originally posted by lo bux racer@Dec 26 2005, 12:40 AM
It's also the only mod that is a Federal violation, and is illegal in all 50 states.
why are the alpha werks one illegal and the other ones arnt? i know in the pictures it looks like the megan ones have a cat but they say they dont sell them like that anymore?
 

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Originally posted by WTC_81+Jan 26 2006, 12:19 PM-->QUOTE (WTC_81 @ Jan 26 2006, 12:19 PM)
<!--QuoteBegin-lo bux racer
@Dec 26 2005, 12:40 AM
It's also the only mod that is a Federal violation, and is illegal in all 50 states.
why are the alpha werks one illegal and the other ones arnt? i know in the pictures it looks like the megan ones have a cat but they say they dont sell them like that anymore?[/b]
All the headers out on the market for the tC are illegal(off road use only), Megan used to make it with a pre-cat, but the cone inside the cat was breaking apart and pieces would end up inside the exhaust, so they redesigned without the pre-cat. Even when it had the pre-cat, it was still illegal.
 

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Originally posted by gwtc+Jan 26 2006, 12:25 PM-->QUOTE (gwtc @ Jan 26 2006, 12:25 PM)
Originally posted by [email protected] 26 2006, 12:19 PM
<!--QuoteBegin-lo bux racer
@Dec 26 2005, 12:40 AM
It's also the only mod that is a Federal violation, and is illegal in all 50 states.

why are the alpha werks one illegal and the other ones arnt? i know in the pictures it looks like the megan ones have a cat but they say they dont sell them like that anymore?
All the headers out on the market for the tC are illegal(off road use only), Megan used to make it with a pre-cat, but the cone inside the cat was breaking apart and pieces would end up inside the exhaust, so they redesigned without the pre-cat. Even when it had the pre-cat, it was still illegal. [/b]
Either way it's still illegal. Let us state it once more:

It is illegal to remove or replace any factory installed working catalyst, even with another working catalyst. Replacement is only allowed in the case of a failed or damaged catalytic converter, and complete removal is definitely not legal.

-Ed
 
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