Stepped Primary Exhaust Extractors

These stepped exhaust headers/extractors appear on Formula One engines. They actually work at the very top of the rp/m range
0:06 purpose
0:13 montage00:34 intro the collector
1:21 primary exhaust
1:53 overlap
2:15 stepped primaries
3:10 effective length

[@dovydasgrigas441]

came here after the maisteer video

[@Darkaccent]

Indeed

[@vercingetorige400]

still trying to get my head around the idea

[@smn368]

Shit .... Me too . I thought I found one far enough down the list 😂

[@smn368]

​@@vercingetorige400think of sound waves being bouncy balls and the stepped headers being a wall of teeth .... Once that bouncy ball of sound hits the wall of teeth, it bounces back and splits into more bouncy sound waves That are only half the size but are moving twice as fast

[@LeachimSagrav333]

So does the sound work in conjunction with a particular firing order?

[@icandreamstream]

WELCOME TO THE MAISTEER PREQUEL

[@D1PAYAN]

My man!! ❤

[@OGChadney]

Came here from Maisteer

[@SupraSav]

**Warning, headphone users**... Bro decided to start the video at the loudest possible part....

[@OVERKILL_SS]

Got recomended after the maisteer video! 😂

[@happi6969]

reminds me of 2 stroke exhausts

[@SteelyEyedMissileDan]

I love a nice 2-stroke exhaust note. God, I miss the days when those smoky little torque monsters were a dime a dozen.

[@davidwickboldt712]

Same principal, but on a 4 stroke the step is increasing the negative pressure behind the wave. Sucking out the cylinder. You don't want a high pressure wave pushing into that cylinder during overlap. Also like a two stroke the lengths are critical to valve timing.

[@onemantwohands5224]

Excellent explanation 🙌💥💥

[@MrBlackbutang]

This is a special edition ❤

[@forbiddenera]

Endyn for the win!!

[@simraceski9995]

Wonderful

[@volodymyrforos1031]

Brilliant

[@andreasbeier2431]

And they sound good

[@therank1776]

when the wave coming back from the splitter hits the step in the header does that also send another wave back out doubling in the opposite way assisting again before its reflected at the cylinder?

[@Drunken_Hamster]

Can you make multiple steps in the primaries, or do subsequent steps have to be done with the secondaries and/or rest of the exhaust?

[@anpredictable]

Is the the stepped only meant for the headers? What about after the collector? Its hard to find a good welder that can do it 😢

[@Corpsecrank]

I wonder if it would be worth looking into for a drift car that is staying in the high rpms.

[@ovalwingnut]

You R the "Primary Exhaust Gas Whisperer"

[@jamie101010]

This video doesn’t really describe how they work.

[@mrmadunit3923]

[@joshfoley8862]

You need to press that sideways triangle in the center of the video.

[@dons1932]

In short. Stepped headers do not cause a high pitched sound. They improve scavenging in the pipe, which when the pipes are all tuned length and put into proper merge collectors with even more scavenging, will make a beautiful sound. Every entire race exhaust ever is built with scavenging in mind, so it's nothing new. Some scavenge better without that design or hence sound. Which is why it had its time and isn't seen much anymore. People like Burns Stainless have known this for years. They have said you could - and they have built one - a header system that is constantly tapered to keep stepping up and up and up all the way along its length. But time and cost do not make this beneficial.

[@jdoe9518]

Any sudden change in diameter will change velocity. The change in diameter and velocity creates a pressure wave reflection point. This design does not change the sound of the engine in any significant way. All exhaust designs will only produce optimum performance within a small window of RPM due to gas volume and velocity vs pipe diameter and length. The stepped design, when done correctly, will give a slightly broader RPM range with a higher level of efficiency due to reduced pumping losses and less intake charge contamination due to the pressure wave/pulse/reflection tuning that assists cylinder scavenging.

[@chrissmith7669]

Are the stepped headers only effective for very high rpm engines or are they effective at RPM seen by street or Autocross type engines.

[@PSA78]

Headers have to be tested on a dyno (combined with anything else that's changed), perfect simulation require data that's hard to determine, so in the end it's quicker and more precise to test if it's of benefit for the specific combination (as well as where they should be, and a number of other things).

[@Manchild..dadchild]

I want to kno if i do a short tube header an a longtube header on my i6.. will i get the unequal length headers sound like a subaru? Plus would love to add this to that set up heavenly?? Oh.. its a low power e46 bmw.. so power not wat im really after.jus enjoyment of sound shifting gears etc.. an maybe little pwr added wouldnt kill me lol

[@MarcusPin]

No. Uneven headers kill a balanced I6. The only way you get tthat good sound and choppy rumble from a subaru is only enhanced by the headers. On an e46/the M5x platform a set of good even length catless headers make way more benefit than uneven length.

[@CL9k24a3]

why would some one chose straight step like on 8sec pic instead of taper step like on 18sec pic?

[@CyberDogFIN]

fabrication? And you have to remember that the inside of the pipe does look different than the outside. But if we think about the sound. The radius of the bend (step if you will) does not matter if the lenght of the sound wave is (if I remember correctly) twice the diameter of the radius. So in header scale it does not really matter. For the flow of the gas it does matter if the pipe is smooth, it generally flows better. But as the exhaust gasses are resonating a bit of turbulance might even be beneficial in some situations. It's way over my head thou.

[@dons1932]

You can see on the lower pipe it has a belled end flange to make it easier to weld. Stepped headers are very hard to build cleanly by not contaminating the inside o f the pipe.

[@ajwright5512]

Are stepped manifolds used with Turbocharged engines?

[@Mart77]

I dont think it would have any significant effect

[@Christdeliverme]

Yes. You just have to realize that the turbo or open wastegate ends up being the terminating point to the wave. That's why it's good to have a secondary coming off of the collector before the turbo - but of course the downside is on the street when the exhaust plumbing can cool it'll introduce a bunch of lag until the primaries and secondaries get hot.

[@Christdeliverme]

And you need to pay attention to the cam.

[@mrmadunit3923]

WOW Ok then on a 1 cylender 2stroke motocrosser HAS AN EXPANTION CHAMBER and thats the exact same reson Now im eyeing my poor little BLUE mazda2 no no NOOOO!!!!!

[@MrDarkodude]

Guys how would sound a K20 with this stepped header ? like a bike engine ?

[@Kenneth_Ben]

I've wondered this, I can't seem to find anyone on KZbin who has done it, I'm sure it would sound like one but it won't rev as high of course.

[@Mortal_3j4]

Would love to see it on a v6. I have heard some v6s that sounded a teeny tiny bit like v12 but lacked that _something_ . It may be the missing piece of the puzzle

[@hobbies2902]

Seconding this, I want to hear it on a 4 Cylinder car motor.

[@fancyfox3602]

@@Mortal_3j4 That *something* is probably an extra 6 cylinders lol

[@Mortal_3j4]

@@fancyfox3602 lmao, true

[@baileykelso7771]

My harley's exhaust has this, kick ass!

[@sabercruiser.7053]

🔥🔥🤌🤌

[@ronnieboucherthecrystalcraftsm]

i like subaru turbo ! small sounds great and power to match some v8 engines = i challange motor bikes and porsches ! - usually win .

[@Sinisterstreetcars]

Wrong.. they are anti reversion chambers