1 3/4-1 7/8 stepped vs. 1 7/8
10-15-2010, 01:23 AM
#1
1 3/4-1 7/8 stepped vs. 1 7/8 hey there, are there any dyno sheet comparisons for 1 3/4" stepped headers to 1 7/8 vs. full 1 7/8 headers? ive been searching and searching but cant come up with anything. has anyone used stepped headers and then gone to 1 7/8 and seen a difference? thanx
10-15-2010, 11:01 AM
#2
oh also, just from hear say, some people say that using 1 7/8 is a waste of money, that there really isnt any more benefit when using this large of primaries compared to 1 3/4 stepped headers. others say that there is huge performance gains compared to 1 3/4 primary headers. any input to shed some light on this subject?
10-16-2010, 05:59 AM
#3
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I have never seen a comparison between thoose 2 but I have seen 1 3/4 vs 1 7/8 headers and the 1 7/8 lost nothing down low, picked up 8rwhp at peak and a little bit mid range.
10-16-2010, 03:15 PM
#5
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Yeah all the comparisons I've seen have showed no loss down low and more gains up top. The problem being these are usually comparing a budget 1-3/4 header to a high-end 1-7/8 header. That said I'm probably going to go with the 1-7/8 headers when I get mine. Bigger is better right 
?
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10-17-2010, 03:04 AM
#7
Why is there barely any information on stepped headers? It seems like no one runs them.
also when would be a good time to upgrade to 1 7/8 to get more performance?
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10-17-2010, 03:24 AM
#8
From what I understand is that the step head is supposed to scavenge better. Most step headers that I have seen are considered a race or competition headers. I am going to run a Edelbrock Victor step header on my car. I actually have a set of new 1-3/4 set of jet hot headers and a extra set of new Edelbrock Victor step headers for sale. If you are interested, let me know. Ill make you a heck of a deal on them.
10-17-2010, 03:26 AM
#9
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I'm curious about stepped too. They seem like they'd be more effective at scavenging because of the design vs. the regular. Seems that no one runs them though so there must be some reason.
10-17-2010, 03:33 AM
#10
Well supposedly 1 7/8 helps a little on the top end and loses nothing on the bottom end on even a stock motor, and only helps when you do heads/cam. However....
https://ls1tech.com/forums/dynamomet...results-2.html
So while bigger headers are definitely better at some point, it's all about the total combination of things....I guess
https://ls1tech.com/forums/dynamomet...results-2.html
I've posted this about a thousand times, but I'm going to post it one more time.
In the back to back testing we did, heads with 1.55" exhaust valves MADE MORE POWER EVERYWHERE WITH 1 7/8" HEADERS COMPARED TO 1 3/4"
Heads with 1.57" valves seemed to make about the same power either way.
The AFR heads with 1.60" valves made less power with Kooks 1 7/8" headers compared to Hooker 1 3/4" with a cam that had 2 degree split.
So in my humble opinion, his headers were helping his stock heads, but worked against the AFR heads.
In the back to back testing we did, heads with 1.55" exhaust valves MADE MORE POWER EVERYWHERE WITH 1 7/8" HEADERS COMPARED TO 1 3/4"
Heads with 1.57" valves seemed to make about the same power either way.
The AFR heads with 1.60" valves made less power with Kooks 1 7/8" headers compared to Hooker 1 3/4" with a cam that had 2 degree split.
So in my humble opinion, his headers were helping his stock heads, but worked against the AFR heads.
10-17-2010, 03:37 AM
#11
no i dont need any 1 3/4 headers. i have a set of FLP 1 3/4 stainless LT's on mine.
a friend of mine told me a while back that there really isnt any perormance gains from 1 3/4 to 1 7/8 primaries, at least none that are notable unless you're running an all out race motor that revs high, but the 1 3/4 stepped is better for street motors. and i mean this guy is all LS like the rest of us are and i started thinking about it a couple days ago. but it would seem like the stepped are better because once the 1 3/4 primary steps up to 1 7/8 it would be literally sucking the exhuast out of the cylinders to fill that space. kinda like putting a syringe on your thumb and pulling the plunger on it till it resists, then pull your thumb off the opening and you can hear the air being sucked into the syringe to fill the vacuum right?
a friend of mine told me a while back that there really isnt any perormance gains from 1 3/4 to 1 7/8 primaries, at least none that are notable unless you're running an all out race motor that revs high, but the 1 3/4 stepped is better for street motors. and i mean this guy is all LS like the rest of us are and i started thinking about it a couple days ago. but it would seem like the stepped are better because once the 1 3/4 primary steps up to 1 7/8 it would be literally sucking the exhuast out of the cylinders to fill that space. kinda like putting a syringe on your thumb and pulling the plunger on it till it resists, then pull your thumb off the opening and you can hear the air being sucked into the syringe to fill the vacuum right?
10-17-2010, 03:45 AM
#12
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but it would seem like the stepped are better because once the 1 3/4 primary steps up to 1 7/8 it would be literally sucking the exhuast out of the cylinders to fill that space. kinda like putting a syringe on your thumb and pulling the plunger on it till it resists, then pull your thumb off the opening and you can hear the air being sucked into the syringe to fill the vacuum right?
10-17-2010, 08:24 AM
#16
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I don't have very long to reply or find the thread that I originally read this in, but I believe I remember reading that stepped headers do create a better scavenging effect, but that it is focused for a more specific RPM range instead of the entire band. That's why they are for racing, where you intend to be in x-y RPM band for the majority of the time.
Wish I could help more.
Wish I could help more.
10-17-2010, 03:50 PM
#18
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I don't have very long to reply or find the thread that I originally read this in, but I believe I remember reading that stepped headers do create a better scavenging effect, but that it is focused for a more specific RPM range instead of the entire band. That's why they are for racing, where you intend to be in x-y RPM band for the majority of the time.
Wish I could help more.
Wish I could help more.
10-18-2010, 01:37 AM
#19
That makes sense. Header length also corresponds to specific RPM range. I'm sure professional racers spend lots of money to get the right step & length for their specific RPM band. But as with many things race parts don't always translate well to the street. I'd hate to have a street car with headers that were only working best at 5 or 6k.
10-18-2010, 01:59 AM
#20
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The stepped edelbrocks looked nice but you have to weld the collector on which caused a lot of exhaust leaks.
The stepped header is supposed to make the torque of 1 3/4 with the topend power of 1 7/8
The stepped header is supposed to make the torque of 1 3/4 with the topend power of 1 7/8