stepped vs non-stepped headers
Thread Starter
Joined: Oct 2006
Posts: 2,608
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From: Webb City, MO...out in the garage
stepped vs non-stepped headers search isn't turning up any useful info, so i figured i'd post this up in here.
i've got a 454 LSX inbound for my camaro. i have a set of 1 7/8" Kooks headers, but i'm thinking that i might be leaving a little power on the table with them. i know it won't be a LOT, but it's a semi-max effort motor and headers are an easy thing to change.
SO, obviously i'm thinking of going to a 2" header, but someone (not the MOST knowledgeable person) told me that a stepped header will make more power
i.e. the 1 7/8" x 2" will make more power than the 2", is there any truth to that?
thanks,
ben
i've got a 454 LSX inbound for my camaro. i have a set of 1 7/8" Kooks headers, but i'm thinking that i might be leaving a little power on the table with them. i know it won't be a LOT, but it's a semi-max effort motor and headers are an easy thing to change.
SO, obviously i'm thinking of going to a 2" header, but someone (not the MOST knowledgeable person) told me that a stepped header will make more power
i.e. the 1 7/8" x 2" will make more power than the 2", is there any truth to that? thanks,
ben
TECH Regular
Joined: Nov 2002
Posts: 418
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From: Augusta Ks.
From what I read the step will help over the staight pipe but for max it comes down to the engine as each are a little different.So to get max it takes alot of dyno time and some build them your self pipe length to get the timing of the pulses so that one is out of the way and get the max low pressure to pull the next one to get the best flow.
Thread Starter
Joined: Oct 2006
Posts: 2,608
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From: Webb City, MO...out in the garage
From what I read the step will help over the staight pipe but for max it comes down to the engine as each are a little different.So to get max it takes alot of dyno time and some build them your self pipe length to get the timing of the pulses so that one is out of the way and get the max low pressure to pull the next one to get the best flow.
basically, the motor is a 454, callies compstar crank/rods with wiseco pistons, cam is 256/266 (IIRC) .646" 112 with TFS 245cc heads. intake will be a FAST ported and opened up to 100mm. M6 with 4.11's in a 9" for the driveline.
the longblock isn't exactly max-effort...at all...but i want to squeeze as much out of it as i can with the bolt on parts like headers, intake, etc...that's why i was wondering which header would be best for it. i know BBC guys will use 2 1/8" headers on their motors, but those heads have entirely different flow characteristics....
the dilema is this: trade my NIB 1 7/8" straight up for slightly used stepped headers, OR sell mine outright and buy some straight 2" pieces?...or new stepped headers?
TECH Apprentice
Joined: Dec 2008
Posts: 372
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From: Kinston North Carolina
As many cubes as you have i would go with a 2" header. I wouldnt bother with the step headers. I wish somebody would make a good pair of tri y headers for the F bodies. Ive dyno tested some tri y's on a roundy round 350 SBC and they really suprised me at the gains of them. They are a 1 3/4 stepped to a 1 7/8 then into 2 1/4 secondaries into a 3" merge collector. They were worth like 15 hp and like 10 or so ft lbs of torque all the way across the chart over a 1 3/4 into 3" collector. They really seemed to offer the best of both worlds.
Stepped headers offer more low-midrange torque and hp while,..as far as a tri-y setup goes jegs sellf the flowmaster scavenger collectors welded up and ready to go..I do believe they affer a 2" primary version where instead of your header coming together in one merge they come together in a 4 into 2 into1..now I believe these collectors paired with stepped headers should give you good low to mid range without sacrificing any topend
Flowmaster Pulse Tech Scavenger Collectors
Product images may differ from actual product appearance.
Gain Up To 15 HP!
Pulse Tech collectors are designed to take advantage of the sequence of firing pulses in the individual header tubes. Use as a retrofit to existing headers or as a collector for custom-built headers. To retrofit, simply cut off the existing collector and replace it with the Flowmaster collector (please measure the exact size of your headers' primary tubes before ordering)1/4'' in length. Expect a 15 hp, 25lbs./ft increase
Flowmaster Pulse Tech Scavenger Collectors
Product images may differ from actual product appearance.
Gain Up To 15 HP!
Pulse Tech collectors are designed to take advantage of the sequence of firing pulses in the individual header tubes. Use as a retrofit to existing headers or as a collector for custom-built headers. To retrofit, simply cut off the existing collector and replace it with the Flowmaster collector (please measure the exact size of your headers' primary tubes before ordering)1/4'' in length. Expect a 15 hp, 25lbs./ft increase
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I don't think you will be leaving pwr on the table but were on the table, stepped is going to move your max power up rpm range, non stepped a little lower on it kooks are good headers unless you go custom.
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interesting read.. heres another good read on header design> http://www.popularhotrodding.com/tec...ech/index.html
Thread Starter
Joined: Oct 2006
Posts: 2,608
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From: Webb City, MO...out in the garage
^Burns makes some badass stuff, some of the best out there...i just don't have the coin for that 
i may get ahold of someone at ARH or Kooks and see what they have to say since they're "in the biz"....probably should've just done that first, huh?
i may get ahold of someone at ARH or Kooks and see what they have to say since they're "in the biz"....probably should've just done that first, huh? I called them both and got similar answers to questions about my combo. Yours is very similar to mine. I'd bet they are gonna say 1 7/8 stepped to 2" with 3.5" merge collectors.
TECH Fanatic
Joined: Sep 2007
Posts: 1,244
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From: hattiesburg, Ms
yeah i was kinda wonderin how the stepped headers would react, i am going 1-3/4 stepped to 1-7/8 on my 346, i could not decide if i wanted to go 1-3/4 or stepped, but i figured the stepped might help my midrange a little from a dyno i saw. i know the 1-7/8 is just to big for my setup. Hope you figure it out, i know how it is trying to find a few pony's here and there.
