Posted By: wyldebill
opinions on step headers - 03/02/15 06:18 PM
ive been told both direction, about step headers. some say it has no value, some say they make horsepower. anyone have any information proving or dis-proving claims?
opinions on step headers
Posted By: MR_P_BODY
Re: opinions on step headers - 03/02/15 06:37 PM
I never did a side by side test on the dyno when I
was building headers so I dont have data but I believe
in them enough that I built a 3 set for the race car
but I built a straight set for the street rod... this
is just a opinion but I think they help if the tubes
are equal length to set up the draw at the proper time
which helps them
was building headers so I dont have data but I believe
in them enough that I built a 3 set for the race car
but I built a straight set for the street rod... this
is just a opinion but I think they help if the tubes
are equal length to set up the draw at the proper time
which helps them
Posted By: dogdays
Re: opinions on step headers - 03/02/15 06:43 PM
And I think they help reversion.
I don't think they hurt in any case.
R.
I don't think they hurt in any case.
R.
Posted By: Locomotion
Re: opinions on step headers - 03/02/15 06:59 PM
I'm a firm believer in "steps". A lot of Stock class cars have step header, some as small as 1 3/8" and go up 1 or 2 more sizes. Persoanlly I use the TTI 1 5/8" - 1 3/4" step headers on my 360. They have a broad application range. I've been 11-teens at 3,540 lbs.
There is a dyno comparison of a variety of OEM exhaust manifolds and a few headers, including TTI, on a mild 360.
The TTI step were several numbers better in HP and torque than 1 5/8" straight and 1 3/4" straight headers. But I'm at work and can't find it at the moment.
As with anything else, the actual results can vary with each different application. Jetting may need to be different from straight headers. But I don't see where they hurt.
There is a dyno comparison of a variety of OEM exhaust manifolds and a few headers, including TTI, on a mild 360.
The TTI step were several numbers better in HP and torque than 1 5/8" straight and 1 3/4" straight headers. But I'm at work and can't find it at the moment.
As with anything else, the actual results can vary with each different application. Jetting may need to be different from straight headers. But I don't see where they hurt.
Posted By: 440Jim
Re: opinions on step headers - 03/02/15 09:18 PM
My 2-cents/opinion:
If your application needs big tubes (ie final dia), then the step header from the initial dia stepped up to the final dia will perform better then a full length of the initial dia.
Using a smaller initial dia can help with clearance to the header retaining bolts in some applications.
I will also stick my neck out (opinion) that any gain from using a stepped header rather than a full length at the final/optimum dia will mostly be at levels at/below peak torque rather than near peak hp.
If your application needs big tubes (ie final dia), then the step header from the initial dia stepped up to the final dia will perform better then a full length of the initial dia.
Using a smaller initial dia can help with clearance to the header retaining bolts in some applications.
I will also stick my neck out (opinion) that any gain from using a stepped header rather than a full length at the final/optimum dia will mostly be at levels at/below peak torque rather than near peak hp.
Posted By: BradH
Re: opinions on step headers - 03/02/15 09:34 PM
That's a topic that could be the basis for a whole lotta R&D to filter out the opinions from the facts.
The fact that they are used in specific top-level categories is a pretty good indicator that they work for certain combinations. How much of what works at that level still applies when you scale back the performance dramatically is a another question entirely... and one I'm in no position to answer from any position of knowledge.
The fact that they are used in specific top-level categories is a pretty good indicator that they work for certain combinations. How much of what works at that level still applies when you scale back the performance dramatically is a another question entirely... and one I'm in no position to answer from any position of knowledge.
Posted By: Locomotion
Re: opinions on step headers - 03/02/15 11:28 PM
Here is the Hot Rod dyno test article on a 360/300hp Mopar crate engine. Most of the info is listed with the pics. The dyno numbers are in the last one.
I wish higher rpm numbers were available for this test or a stronger combo.
Hot Rod Magazine exhaust dyno test.
I wish higher rpm numbers were available for this test or a stronger combo.
Hot Rod Magazine exhaust dyno test.
Posted By: perfmachst
Re: opinions on step headers - 03/03/15 12:43 AM
hi, a few years ago, had a friend with 383 dart stocker. it had step headers on it, 1 5/8, 1 3/4 with 3 " collector. changed to a 1 3/4, 1 7/8, 2" step header. it was worth 4 tenths over smaller headers. then added 3 1/2 dia by 16 " collector, picked up . 15 faster over 3" collector. like you say every car is different.
Posted By: MR_P_BODY
Re: opinions on step headers - 03/03/15 12:50 AM
Quote:
hi, a few years ago, had a friend with 383 dart stocker. it had step headers on it, 1 5/8, 1 3/4 with 3 " collector. changed to a 1 3/4, 1 7/8, 2" step header. it was worth 4 tenths over smaller headers. then added 3 1/2 dia by 16 " collector, picked up . 15 faster over 3" collector. like you say every car is different.
In a LOT of cases the 3.5 collector works better(if
its the correct length)... mainly due to RPM.. the
3" is just too small in most cases but thats what
a lot of the header companies want to run(cost is
one reason)... I put 3.5" on MOST of my headers or
larger
Posted By: Wv68charger
Re: opinions on step headers - 03/03/15 02:02 AM
Trying to find the dyno sheets but when we went from big tubes on the dyno to TTI steps we lost 12 hp ended up having a set of equal length big tubes with 4 1/2 collectors made.
Posted By: LaRoy Engines
Re: opinions on step headers - 03/03/15 02:50 AM
I don't know what engine you are using and what rpm range you are running. I don't have an opinion. But I do have the results on a 600hp pump gas small block dyno test. When we switched from Summit Racing $136 1-5/8 headers to TTI 1-5/8" x 1-3/4" step headers we gained an average of 1 lb-ft and 1hp from 3,000-6,000 rpm. The peak horsepower difference was +12hp @ 6,300 rpm. But boy, for an extra $500 those TTI headers are really pretty.
Posted By: MR_P_BODY
Re: opinions on step headers - 03/03/15 03:06 AM
Quote:
I don't know what engine you are using and what rpm range you are running. I don't have an opinion. But I do have the results on a 600hp pump gas small block dyno test. When we switched from Summit Racing $136 1-5/8 headers to TTI 1-5/8" x 1-3/4" step headers we gained an average of 1 lb-ft and 1hp from 3,000-6,000 rpm. The peak horsepower difference was +12hp @ 6,300 rpm. But boy, for an extra $500 those TTI headers are really pretty.
Myself.. I dont call TTI headers very good.. they
fit nice and are fairly easy to install... thats it
and they sure arent made for max power... NO shelf
header fits ALL
Posted By: Wv68charger
Re: opinions on step headers - 03/03/15 03:07 AM
Posted By: MR_P_BODY
Re: opinions on step headers - 03/03/15 03:14 AM
Quote:
https://board.moparts.org/ubbthreads/show...rue#Post8275923
MAYBE they are a closer match to that set up.. but
that would be one set up... I will repeat... shelf
headers dont fit all... they were designed on a single
engine
Posted By: Wv68charger
Re: opinions on step headers - 03/03/15 03:23 AM
Quote:Quote:
https://board.moparts.org/ubbthreads/show...rue#Post8275923
MAYBE they are a closer match to that set up.. but
that would be one set up... I will repeat... shelf
headers dont fit all... they were designed on a single
engine
I agree that's why we went with a custom set
Posted By: dvw
Re: opinions on step headers - 03/03/15 04:43 AM
Quote:
hi, a few years ago, had a friend with 383 dart stocker. it had step headers on it, 1 5/8, 1 3/4 with 3 " collector. changed to a 1 3/4, 1 7/8, 2" step header. it was worth 4 tenths over smaller headers. then added 3 1/2 dia by 16 " collector, picked up . 15 faster over 3" collector. like you say every car is different.
.
The first set must have been crushed. That would be a roughly a 50-60 hp gain. 5 1/2 tenths ET reduction with a header an collector change? Smells a little fishy.
Doug
Posted By: wyldebill
Re: opinions on step headers - 03/03/15 07:11 AM
Here is the combo so far. 560 aluminum low deck, 12.5 to 1. Zeeker heads (-1) indy tunnel ram. A body should be under 3000 lbs. Manuel trans,and a conservative 3.73 gear. 10.5 slick. do you put the big tube on it to kill off a little bottom end?
Posted By: dvw
Re: opinions on step headers - 03/03/15 01:21 PM
Quote:
Here is the combo so far. 560 aluminum low deck, 12.5 to 1. Zeeker heads (-1) indy tunnel ram. A body should be under 3000 lbs. Manuel trans,and a conservative 3.73 gear. 10.5 slick. do you put the big tube on it to kill off a little bottom end?
It'll all depend on your suspension, 1st gear ratio in your trans, and if you have an adjustable clutch. 3.73 isn't much ratio for a stick car. If I could find more low end for my car I'd take it (15-1 572, 4.10, 3340lb, on 10.5) It currently runs 2 1/8" w/3 1/2" collector.
Doug
Posted By: 440Jim
Re: opinions on step headers - 03/03/15 01:21 PM
Quote:Chuck at BEST Machine dyno tested an engine close to that size with a couple pairs of headers. Do a search and see if your engine combo is close to his and the difference it made. As I recall, the really big tube headers made more peak HP, and lost torque below about 5900 rpm. With a high stall converter, you will hardly see that at the drag stripe.
Here is the combo so far. 560 aluminum low deck, 12.5 to 1. Zeeker heads (-1) indy tunnel ram. A body should be under 3000 lbs. Manuel trans,and a conservative 3.73 gear. 10.5 slick. do you put the big tube on it to kill off a little bottom end?
EDIT: https://board.moparts.org/ubbthreads/show...rue#Post8276607
1) 2.125 straight tubes
2) 2.125 stepped to 2.375 then to 2.500 big tubes
Posted By: wyldebill
Re: opinions on step headers - 03/03/15 04:28 PM
im running a 2.45 first. the reason of the 3.73 is im going to try and drive it on dragweek. i dont have an overdrive. i can go to a shorter slick at the track to try and recover some gear. as far as the chassis goes. c/m k member with coilover shocks read in momo leif with assasin bars.there are guys running much faster than me with simmular components
Posted By: Crizila
Re: opinions on step headers - 03/03/15 04:38 PM
Quote:IMO, like many other "innovation's" - over sold. When is the last time you read a new product test done by a car mag that showed the item to be worthless, or at best, no change. Header length, collector size and length, are the game changers.
ive been told both direction, about step headers. some say it has no value, some say they make horsepower. anyone have any information proving or dis-proving claims?
Posted By: Mopar-Al
Re: opinions on step headers - 03/03/15 10:01 PM
I just had mine hand built for my 572 B1 will be testing hopefully this weekend 2 3/8ths equal lenght to 4.5 collector. chassis car 68 dart, launch 45 on brake flash to 6 1250 dom I bought from member here 14.5 comp 180 first 2760 or so with me in it. never was interested in steps
Posted By: Mattax
Re: opinions on step headers - 03/03/15 11:56 PM
There have been some very interesting (and for me eye opening) discussions on SpeedTalk about the first tube off the heads. Page two of What is "blow down" length gets right into it.
My one sentence summary is - If there is reversion in the rpm range you care about, keep exhaust velocity high until the exhaust valve closes.
My one sentence summary is - If there is reversion in the rpm range you care about, keep exhaust velocity high until the exhaust valve closes.
Posted By: MR_P_BODY
Re: opinions on step headers - 03/04/15 12:39 AM
Every portion of a header has a reason... pulse lengths
(or wave lengths).. things need to happen at a timed
point otherwise you end up with things crashing together..
I TRY to get 1 cyl volume from the valve to the tangent
of the first bend.. the first step is at a point
for a reason.. thats to continue the flow in one direction
and the same for the next step.. the tube sizes are
for the velocity and the size is part of where the
step will be... but understand that if the tubes
arent equal length then it MAY not help at all..
when we build a header its with the idea that the tubes
will be equal.. and at a certain length.. this length
is part of the exhaust timing as is the steps
(or wave lengths).. things need to happen at a timed
point otherwise you end up with things crashing together..
I TRY to get 1 cyl volume from the valve to the tangent
of the first bend.. the first step is at a point
for a reason.. thats to continue the flow in one direction
and the same for the next step.. the tube sizes are
for the velocity and the size is part of where the
step will be... but understand that if the tubes
arent equal length then it MAY not help at all..
when we build a header its with the idea that the tubes
will be equal.. and at a certain length.. this length
is part of the exhaust timing as is the steps
Posted By: Mattax
Re: opinions on step headers - 03/04/15 01:46 AM
read Elston's posts Mr P. I think you'll find them interesting and even useful in a practical way.
Posted By: MR_P_BODY
Re: opinions on step headers - 03/04/15 01:59 AM
Quote:
read Elston's posts Mr P. I think you'll find them interesting and even useful in a practical way.
I have read it
Posted By: tubtar
Re: opinions on step headers - 03/04/15 02:51 AM
My " opinion " is that there is power to be gained with a step header..........but you need to build the header to cater to a narrow power band to fully exploit the benefit.
Look at the classes where they are the norm......Comp. and pro stock spring to mind.
Sprint cars and some roundy round guys use them.
Those headers are built with a very specific r.p.m. range in mind.
For a street / strip effort , your gain will be at a cost somewhere.
And for a balls out race car , they are part of a combination of parts that all work together at a given engine speed to deliver maximum performance.
Could you tune them for lower r.p.m. benefits ?
I think yes.
But there is a lot more to it than cutting bends and making sparks , and for anything but a max effort I think they are on the pricey side of the ledger.
Look at the classes where they are the norm......Comp. and pro stock spring to mind.
Sprint cars and some roundy round guys use them.
Those headers are built with a very specific r.p.m. range in mind.
For a street / strip effort , your gain will be at a cost somewhere.
And for a balls out race car , they are part of a combination of parts that all work together at a given engine speed to deliver maximum performance.
Could you tune them for lower r.p.m. benefits ?
I think yes.
But there is a lot more to it than cutting bends and making sparks , and for anything but a max effort I think they are on the pricey side of the ledger.
Posted By: Mattax
Re: opinions on step headers - 03/04/15 03:46 AM
that's the advantage of incorporating blowdown length into the design - it helps a broader band, especially lower rpm. The manifold experiment/test quoted and linked in that thread convinced me. Not many builders share and discuss as generously as he has. 
Posted By: 440Jim
Re: opinions on step headers - 03/04/15 03:46 AM
Quote:What is the length of the tubes you are having built? Longer helps torque, but shorter helps peak hp.
I just had mine hand built for my 572 B1 will be testing hopefully this weekend 2 3/8ths equal lenght to 4.5 collector. chassis car 68 dart, launch 45 on brake flash to 6 1250 dom I bought from member here 14.5 comp 180 first 2760 or so with me in it. never was interested in steps
Posted By: Mopar-Al
Re: opinions on step headers - 03/04/15 03:59 AM
I will have to measure to give a real number for you. The are a lot shorter than my last. These maybe 32/34 just got to see
Posted By: Streetwize
Re: opinions on step headers - 03/05/15 04:59 PM
I think if you are under geared, heavy or under compressed....and/or have a little too tight of a converter they are a real benefit, as Jim's chart shows there is a torque trade/off probably a benefit on any street or dual purpose car overall. But that said there is much more to efficient header design than just the first 6-8" of primary pipe. overall size, Length and Collector size are equally important....like anything else, it depends on the combo.
Even on a bracket car I can see where a step could help keep the car more consistent, basically anything that boosts torque below the torque peak can be useful....provided you can hook it all up
Even on a bracket car I can see where a step could help keep the car more consistent, basically anything that boosts torque below the torque peak can be useful....provided you can hook it all up
Posted By: Alchemi
Re: opinions on step headers - 03/12/15 10:19 AM
Quote:Quote:Chuck at BEST Machine dyno tested an engine close to that size with a couple pairs of headers. Do a search and see if your engine combo is close to his and the difference it made. As I recall, the really big tube headers made more peak HP, and lost torque below about 5900 rpm. With a high stall converter, you will hardly see that at the drag stripe.
Here is the combo so far. 560 aluminum low deck, 12.5 to 1. Zeeker heads (-1) indy tunnel ram. A body should be under 3000 lbs. Manuel trans,and a conservative 3.73 gear. 10.5 slick. do you put the big tube on it to kill off a little bottom end?
EDIT: https://board.moparts.org/ubbthreads/show...rue#Post8276607
1) 2.125 straight tubes
2) 2.125 stepped to 2.375 then to 2.500 big tubes
What would be an interesting addition to that chart is some 2.375 & 2.500 sized straight tube headers too
If anything the tubes should get smaller as the gas cools along the pipes - but logic and physics rarely mix
