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View Full Version : power difference...4-1 header vs 4-2-1 header


marcos713
10-09-2009, 02:06 AM
as title states i want to know what the power difference of a 4-1 header on my gsr as opposed to a 4-2-1 header. ive heard 4-1 headers are better for vtec engines b/c of the better flow, but i hate scraping all around town.. so if its not that much of a power difference, i might switch over to 4-2-1 headers. my bolt-ons realted to this are, my skunk2 2nd gen IM, CAI, and greddy evo2 exhaust w/ str8 pipe.

all input welcome!:goodjob: thanks in advance
RBS
10-09-2009, 09:39 AM
supposedly 421 is more oriented towards midrange torque and the 41 are oriented towards topend
D3UC3S
10-09-2009, 09:49 AM
supposedly 421 is more oriented towards midrange torque and the 41 are oriented towards topend

exactly what i was about to say! This man speaks the truth!
EJdm
10-09-2009, 10:11 AM
^^^what he said...
J-ROCK
10-09-2009, 02:16 PM
plus 4-1 you dont have to worry about a flange leaking
silverDA
10-09-2009, 06:26 PM
41 you gotta worry about scrapeage,i prefer the 421 easier to take off if you have a DA or EF/
blue94eg6
10-09-2009, 09:59 PM
4-1 is better on highways compared to 4-2-1 is better for street runs
blacknightteg
10-09-2009, 10:02 PM
i like my 4-1 helped give me good numbers on my b20.
marcos713
10-09-2009, 11:08 PM
4-1 is better on highways compared to 4-2-1 is better for street runs

o realy? soo if i were the type of person that does street runs, 4-2-1 is the way to go?:ninja:

definetly hate the scrapeage part!!
RBS
10-09-2009, 11:12 PM
4-1 is better on highways compared to 4-2-1 is better for street runs


makes no sense.

if your on the highway at 7k rpm and on the street at 7k rpm, whats the difference? :doh:
Black4DrEK
10-09-2009, 11:30 PM
^^^:lmfao:

wow.


Aye man keep your 4-1 IMO
LSTurboHatch
10-10-2009, 01:36 AM
^^i agree. or get a vteckidd narrow header. i have plenty of clearance with it and it makes a huge difference.
G.C
10-10-2009, 11:24 AM
When you guys say "Big" difference, did you actually dyno your car before the header and after? or are you guys just guesstimating.
RBS
10-10-2009, 11:54 AM
When you guys say "Big" difference, did you actually dyno your car before the header and after? or are you guys just guesstimating.

makes a big difference on a Butt dyno! every pull is a different result because you can never sit in the same, exact spot lololol
TommyD1919
10-11-2009, 08:52 PM
I don't think going from stock manifold to header on a GSR is a BIG difference, Whats it like 6hp or so... I would think the diff. from 4-2-1 to 4-1 could only be a couple hp anyways... If you have one or the other it def. wouldn't be worth the time or money to swap... I have always had 4-2-1s on my cars but have installed many a 4-1...
D3UC3S
10-11-2009, 11:20 PM
When you guys say "Big" difference, did you actually dyno your car before the header and after? or are you guys just guesstimating.

when Mike tested the h22 drag header on my car we did a before and after...+14whp...no guestimating, his shit makes power
marcos713
10-12-2009, 01:19 AM
http://www.fastlineperformance.com/skidplate.htm

i could fasten this down on my header with some exhaust clamps couldnt i? or would it be better welded?