Why the 4-2-1 vs 4-1 debate is STUPID

[@Josh-py2in]

It's very simple. Your primary diameter and length determine the exhaust velocity. Higher exhaust velocity equals more power. Headers with bigger diameter and long tubes will slow down exhaust velocity until you are way up in the rpm range.

[@luisgrajeda4147]

so its better lower diameter on exhaust tubes for more performance?

[@dTheHammerb]

4-1 shorty headers say otherwise, as continuously proven for years now. Long Tube Headers have always been made for low to mid-range while having some gain at the top. Short Tube headers are almost exclusively designed for top range power at the cost of low to mid-range.

[@bass2762]

@@luisgrajeda4147 Depends on where in the rpm range you want to make power.

[@dave_ecclectic]

not only can't I understand him but neither can the closed captioning. His drawings suck and he seems to never explain the WHY of the title. His including of sensors makes no sense as you don't need sensors for headers to work. Some cars use Carbs and this issue is not a 'honda' thing but an issue of more torque over a wider band versus more HP at peak.

[@chrismagalona9592]

Another explanation why you'll lose power when your pipe is to big is because with an oversized pipe, "scavenging' doesn't happen. What scavenging is really is a process in which the rush of exhaust gases is so strong it helps pull more fresh air in the intake valve, thus putting more air to the cylinder.

[@marcust510]

He spelled secondary “2ndary” 🤯 I’m using this bro 🙌🏽

[@peterkenny6383]

Clearly you know nothing about how an exhaust system works

[@findtherightbeat]

Could you please confirm if you have an automotive engineering degree? Additionally, I’m interested in understanding the foundation of your theory on building exhaust systems. Could you provide specific details on the principles or research that support your approach?

[@speedlabchannel4452]

I have a manufacturing engineering degree Which includes automotive

[@karlmoltzan6196]

4-2-1 headers are also called tri-ys. For an inlins 4 cylinder i agree with you. But on a big v8 theu do make more torque down low. This is because of the extra cylinders an more firings per revolution. Americans have been 6sing tri-ys since the 1950s look up Doug Thorley. He was the master.

[@speedlabchannel4452]

My video never touched on v8s

[@suzysuzuki8865]

I have a Doug thorley on my samurai lol

[@2good4uyt10]

that's more specifically because of the firing order on those v8s, some v8s may have a decrease in performance due to 4-2-1s.

[@muftifaizan1964]

For a 1.6 SOHC engine with stock cam and 3.5 points raised compression to 12.5:1. Upto how much length should the primary 4 tubes of headers be, in both 4-1 and 4-2-1 (and secondary lengths) setups ? Street application. G16b engine.

[@JakeTheCrow]

What it all boils down to is flow. It’s old school knowledge anymore, which is a shame. It’s all in the effort of making what you have more efficient. There is the principles of scavenging, which can be argued but mopar proved it with ram air. Quicker evacuation, less resistance (better flow and heat management), heat is necessary for flow. You can spend all the money you want on “performance” exhaust and pull it out of the box and there’s a fat weld inside of a flange restricting flow 🤦🏼‍♂️ Do some research, break out some books. And try things for yourself. You will never regret having more knowledge. Expect that you will find yourself addicted.

[@makantahi3731]

i have v8 , and intend to make long tube header and it seams easier to weld 4-2-1 than 4-1, firing order is 1-8-4-3-6-5-7-2, (now i ask for right side)what cylindres to weld together: 8+2 and 4+6 and then they together , or some other combination, what is ideal diference in degreas between exhaust pulses: 90/180/270/360?

[@Drunken_Hamster]

The best thing to do for a crossplane V8 is to make an 8-into-1 that fires in a rotary/sequential pattern. Basically, pic a direction clockwise OR counter-clockwise, and then attach equal length primaries to the collector in that manner according to your firing order. The next best thing you can do is 180-degree headers while also making each 4-into-1 side have that radial firing pattern. (Also do an X-pipe or an increasing diameter Y-pipe at a roughly 4/3 size ratio if you want to further maximize scavenging while also preventing it from sounding like two 4-cylinders playing together) The next best thing you can do if you don't want to do either of those is try to make sense of the madness that is David Vizard and make a purposefully UN-equal length header for each side that would make the un-even firing of each bank even out by delaying certain cylinders' exhaust pulses from getting to the collector via making the primary tube longer. NOTHING else is the technically correct way it if you're trying to maximize scavenging for a crossplane V8. If you're not willing to put in any of the above work, you might as well buy something off the shelf and ballpark the primary and collector diameters.

[@makantahi3731]

@@Drunken_Hamster thank you

[@imadude85]

@@Drunken_Hamster I've read somewhere that 8 into 1 header makes less power because the resulting collector size would be too big to promote good scavenging.

[@kevinalvarohilares3793]

Whats better for a Toyota Corolla 1.5 cc, 4 2 1 or 4 1?

[@speedlabchannel4452]

4-211

[@Blenzo480]

I have no clue what this guy is talking about. I recommend reading Scientific Design of Exhaust & Intake Systems by Philip H. Smith and John C. Morrison If you actually want to understand exhaust design.

[@speedlabchannel4452]

☝️yes follow this idiot

[@johnwoodrow8769]

This guy doesn't know what he is talking about. The primary difference between 4-2-1 and 4-1 exhausts is the length of the pipes in relationship to the size of the collectors. All changes in diameter create backpressure waves. The choice of design determines what RPM and size of those backpressure waves enter back into the cylinders, and potentially back into the intake (due to valve overlap). There wouldn't be a modern race bike on the planet still running a 4:1 exhaust. Think about that.

[@ndubpcplug6149]

Ty someone that actually give a real life comparison. Not just hypothetical or videos w/ exhaust. So ur saying 4-2-1 is best for performance. What about deeper more throaty sound? Is this true that if u have an LS which I've heard has more bottom end power then 4-1 would b best for you. I have a GSR top end power so 4-2-1 would be best option? Ive owned a 97 LS 4-1 and I loved that car sounded deep throaty before stolen. Then I got 2001 GSR chipped key thank God or it would of been stolen 5x by now. Welcome to Seattle. 4-2-1 it doesn't really feel all that different. Rn I have the 2 piece header which r smaller diameter. Then there's also length of 4 before it becomes 2. Also what about the ones that look like Ram horns? Why. Then what changing the length of one side like Subaru does to get that classic Subi sound. Whenever u get a chance or anyone plz lmk becuz I don't have the $ to buy both. And I love my car but just want a little more umpffff. Thanks for reading I know it's a novel sorry

[@Hectorszenshopedc]

Exhaust manifold is less than half inch in stock Civic.. very tiny for full horsepower capacity of engine block... over 1 inch for racing manifold to take away pressure for high speed.. I bought manifold 2 inches for my birthday.. 15 horsepower more as advertised

[@speedlabchannel4452]

Are you sure you measure the stock correctly?

[@Hectorszenshopedc]

@@speedlabchannel4452 yeah, the pipes go thin before the catalytic channel, 4 to1 by primary O2 sensor to 2 channels to 1 on the secondary O2 sensor before resonator and muffler... I checked the outlet size.. I took out heatshield to save weight... I put extra cooling fans on switches for parking and camping.. lol the beach lifestyle is savage... they made a funnel type exhaust manifold so it dump from each combustion chambers to the catalytic ... .. Saves gas ⛽ 👌 but no torque at mid range rpm.. .. the V6 Odyssey pass me all the time and my heart just climbs and I think I lose my breathe 🤭

[@umarkhan-np9ou]

What about R18 civic only a straight pipe is added instead of CAT how can we improve power on R18

[@gba7806]

Does removing catalytic converter without tuning gain power and improve fuel consumption?

[@speedlabchannel4452]

Most cars yes power Fuel consumption no

[@gba7806]

⁠@@speedlabchannel4452for wigo 2016 does bolt on downpipe make power?

[@speedlabchannel4452]

@@gba7806 headers, not downpipe

[@gba7806]

@@speedlabchannel4452 sorry my bad, does bolt on headers make power for wigo 2016

[@speedlabchannel4452]

@@gba7806 ours does, others no

[@robertconcepcion547]

Is it ok to remove the catalytic converter if im going to install headers? What would be the effects to the engine when removed?

[@speedlabchannel4452]

Yes it's ok

[@fpd-6912]

Less restrictive for engine , gas running faster with faster airflow , engine could run lean mess up air fuel ratio and create more heat .Remap ecu to fix it

[@baljeetspp3602]

It’s completely fine, just get spark plug defaulters to trick the rear o2 sensors if you have them, it gets rid of the engine codes it throws

[@Ingris1441]

For an integra for an NA build, 421 or 41?

[@darrenfisherman3838]

I wanted to know the same thing

[@SlowSTEN]

This ...explains nothing.

[@speedlabchannel4452]

that's fine, you know nothing and your comment also means nothing

[@johnsolante5511]

Sir panu po kpag VIOS gen 3 AT, dual vvti DOHC??? Panu po kya headers nya? 4-2-1 or 4-1??? Slamat po🙏

[@speedlabchannel4452]

Punta ka sa shop at bumili Sabihin ko sayo

[@mohammadyousuf4619]

please any summery, you prefer 4-2-1 for inline 4 cylinders?

[@speedlabchannel4452]

Mohammad Yousuf depends on the engine, what the goal is, how much money you want to spend There is no absolute answer

[@Fawazalsobay]

@@speedlabchannel4452 how about v8 engines ? I heard the try y headers will provide better performance due the scavenging effect at mid rpm while the 4-1 will at top rpm range

[@tonyongtv8347]

Boss you said on another video that making your exhaust pipe bigger also increases your power, is it because it needs to be tuned also while increasing the pipe size?

[@speedlabchannel4452]

That's for turbo cars

[@SlowSTEN]

It depends on how much PSI and CFM your engine is running at. Say a turbo 2.2L L86 Ecotec will love a 3 inch total exhaust (and each runner will be a larger size) then a 2.2 L86 will use a 2.5 inch total exhaust and smaller runners for a higher exhaust velocity and scavenging effect, that's how the common misconceptions of your car needs back pressure when in reality it needs exhaust scavenging.

[@speedlabchannel4452]

@@SlowSTEN when idiot youtubers comment with something totally unrelated to the video SMH

[@Velocity0428]

Is 4-2-1 better than a 4-1 for an Altis?

[@speedlabchannel4452]

Ues

[@somedude9316]

my 87 Camry is straightpiped and has the 4-2-1 wildcat headers in it. No cat, Idk how much it increased performance but I think I got better gas mileage from it. Do you think a 1st gen 3s-fe really has any benefit to the cat delete 4-2-1? The engine doesn't really flow that much air iirc lol.

[@johnsheetz6639]

😆! Bro enjoy! I did the same thing with a 2.8 Chevy motor back in the day

[@Aiihki]

Sir sa hyundai elantra 2011 (1.6) 421 or 41? Please reply

[@speedlabchannel4452]

4-1

[@Aiihki]

@@speedlabchannel4452 thank you so much sir

[@TheMrmagic101]

Plm try Y / RF V2 / Power Driven Sp/ for B16A what are the differences im aiming for the best one for more low end and mid range torque hp. As I have a different manifold that loses mid range for more peak Power at 7,000-8,000 rpm

[@hishammangadang9996]

Sir, paano sa Toyota vios gen 3 Dual VVTI 1.3 which is more preferred? 4-2-1 or 4-1?

[@nikkologs8546]

Pwede kaya sir palitan ung mid pipe lang ng montero 2017 . Mababago ba tunog? Papalitan ung stock muffler ng resonator lang

[@benzvibal]

Sir boss amo, sa GA16DE eccs sentra gen1 4-2-1 or 4-1 headers? Currently nka stock logtype akong headers pero straight pipe resonator delete.

[@speedlabchannel4452]

4-2-1 long tube

[@rowenasuarez5639]

sir is down pipe also useful to increase power

[@speedlabchannel4452]

As a general rule yes

[@thaieralawadh2223]

@@speedlabchannel4452 Thank you for the video. I have classic car with Lexus 3UZ engine in it will a longer custom exhaust better than a pipe ends at the mid of the car? Also, what dimeter pipe exhaust you would recommend? Also, adding 2 mufflers will it help with back pressure or you recommend deleting the mufflers? - forget about the sound. Looking for more torque mainly. Many thanks!

[@glazelg.a6699]

Sir sa honda civic fd na k20z2 2.0 engine ano maganda ilagay 4-2-1 or 4-1???

[@jennyrocila2918]

Question lng sir pag 1.6 lancer ex manual ano po mas better pra sa power 4-1 or 421inaakyat ko kse sya lagi baguio nbbitin ako. Btw stock all in po manual here. Thank you!

[@speedlabchannel4452]

@@jennyrocila2918 4-1

[@johnmenarddesamero8607]

Sir ano po advisable na size ng pipe for Nissan almera 1.5 planning to delete catalytic then place mid pipe with reso naka oval muffler napo ako salamat po

[@Chrizke22]

what about for motorcycles?

[@zakx2623]

Which is better for Honda civic fd 2.0s

[@Difacts-p3z]

Ano po best headers sa Toyota Celica GTS with VVTL-I? 4-2-1 or 4-1

[@speedlabchannel4452]

4-2-1 with Unichip tuning

[@tanyguch_kun1330]

4-1 gamit ko 2zz tas sheeodog n1 muffler

[@floydthedroid5935]

Is there a 421 design that pairs 12, 34?

[@speedlabchannel4452]

Yes. The wrong kind of design

[@floydthedroid5935]

@@speedlabchannel4452 thanks for the reply. If the firing events are as usual, 1342 then does it follow that the exhaust gas pulses/pressure waves can assist with creating a vacuum for additional cylinder filling/volumetric efficiency improvement? I do agree with your overall point, just asking for clarification.

[@JaydenET]

Skunk 2 Alpha header for Civic/RSX, it has a unique sound to it

[@beniirama4076]

its called non sequential 4-2-1. it act like a 4-1 with stepped tube.

[@JaydenET]

@@beniirama4076 it is sequential, meaning 2 pulses go sequentially down each secondary (left left right right left left right right). The normal type would be a 360 degree 4-2-1, 1 pulse down each secondary every 360 degrees (left right left right)

[@fpd-6912]

just went from 421 to 41 long tube , just feel better for old cars or motors need to rev to reach the powerband

[@angelosalas1152]

Hindi na magiging problema sa lto registration pag delete cat then full exhaust?

[@speedlabchannel4452]

Hindi

[@angelosalas1152]

@@speedlabchannel4452 how about fuel consumption? Pang araw araw lang pero naka full exhaust no tuning, ok lang ba to? Plan ko talaga magpagawa sa inyo eh.

[@speedlabchannel4452]

@@angelosalas1152 no change in consumption

[@Aki-vd2xl]

For sentra b13 ga16de engine ano maganda 421 or 41? Kayo din ba nag bebenta nga mga scav?

[@speedlabchannel4452]

We don't sell stupid shit like scav

[@jammingboytv540]

Sir Syd pano po pag 2010 Lancer Ex Gta headers 4,1 po ba or 421? Thank u.

[@speedlabchannel4452]

4-1

[@jammingboytv540]

@@speedlabchannel4452 thank u Sir Syd da best ka talaga.

[@royce4779]

pag deep bass sound lang ang habol no need to change na ba c headers? and ano ano ung need to achieve deep bass sound lang? ung hnd nman habol ung additional hp.

[@speedlabchannel4452]

Oval muffler and mid silencer

[@royce4779]

How much sir ang abutin nito sa shop nio ung ganyan lang kasama intallation? sorry sa paulit ulit nming tanong :D

[@speedlabchannel4452]

Paulit ulit nga tanong mo and di mo pa din sinasabi ano kotse

[@royce4779]

and ano pong size ng scav ang pwede sa honda city 1.5

[@speedlabchannel4452]

@@royce4779 1.75” pipe 14” silencer 4500 Borla muffler 12500

[@mjmj9396]

Sir how about gen 3 vios at trans. What type of headers would i get?

[@speedlabchannel4452]

4-1 We have a long tube 4-2-1 that makes a lot of power BUT you will need to get Unichip inorder to make that power

[@mjmj9396]

@@speedlabchannel4452 about that sir for the headers and the unichip only how much will it totally cost?

[@speedlabchannel4452]

@@mjmj9396 54000

[@ryanventura5216]

Magkano sir aabot pag remap at palit ng pipe sa calibre manual tnx...

[@speedlabchannel4452]

Ecu remap 25000 Exhaust magnaflow 32000

[@Dark_King0801]

Hi sir planning on changing my headers for honda city 97, 4-1 to 4-2-1 is it okay? Do I need to remap my ecu?

[@speedlabchannel4452]

4-2-1 Unichip 30000

[@alfredomarcelo2526]

Location pls

[@speedlabchannel4452]

Check your other comment

[@mark-sd4wo]

why do they prefer 4-2-1 headers that 4-1 on most car, like fremuff they said 4-2-1 makes more power than 4-1

[@Hectorszenshopedc]

4-2-1 is less than 1 inch... Intake then exhaust system. Maybe turbo last.. get on simulations

[@speedlabchannel4452]

It’s a preference, not grounded in any science Just like perfume and soap

[@thedude3189]

Wrong, I seen dyno comparison a 4-1 header made more peak power top end. 4-2-1 is good for low mid doesn't lose much up top I think it was a 2hp difference...alot of people are getting the 4-1 megaphone header for a drag car. Asp makes a nice header too

[@TheSMARTREY]

What happens when you put a 4-2-1 design on a vios gen 3? 1nzfe

[@speedlabchannel4452]

Power and torque loss unless tuned by us. And only we can tune the vios

[@syjohntaraki6246]

sir pano pag gallant v6 ano po gagamitin.thanks po

[@speedlabchannel4452]

6-2-1

[@jekpagatpatan1839]

may branch kau sa davao?

[@speedlabchannel4452]

SpeedLab etuner Mindanao

[@jekpagatpatan1839]

@@speedlabchannel4452 sa Davao city to mismo?

[@speedlabchannel4452]

@@jekpagatpatan1839 yes

[@jekpagatpatan1839]

@@speedlabchannel4452 yun ba yung sa toril?

[@speedlabchannel4452]

@@jekpagatpatan1839 contact him

[@BongoBennieTV]

4-2-1 is way older than the internet, this guy is a foo

[@acewarren14]

Hi Sir anu po ang difference using stainless headers vs cast iron po. Sorry Sir. not so familiar sa car. Can you please share you kind thougths Po.

[@speedlabchannel4452]

Cast iron is original Stainless is performance

[@JasperSkallow]

Only what you breathe in can be breathed out

[@dgreattoyzki3997]

Panu kaya kapag mirage g4? 3 cylinder?

[@speedlabchannel4452]

Then 3-1 is the only option

[@dgreattoyzki3997]

@@speedlabchannel4452 sir sa g4 po ba unichip and headers kasam na ba dyno? magkano kaya magagasto po?

[@speedlabchannel4452]

Dyno is included with Unichip Only MT vehicles can be dynoed

[@konnerkramer329]

If the best engine builders in the world (aka Nascar engine builders) are using tri-y headers there's clearly an advantage. Ill trust the guys with a multimillion dollar research and development budget that spend 12 hours a day on an engine dyno trying to make a couple more HP at a time Over an Asian with a whiteboard.

[@l0stcluster2]

everybody use honda formula

[@florantegalamgam2231]

Pag nakita ko ito sa personal hahalikan ko siya Marami akong natutunan sa kanya kesa sa barbero ko

[@Kenny-fy8xn]

He asian, I trust what he said!

[@jmridewithmetv2833]

Nice sir sid very informative talga,,speedlab the best PO🤘🤘🙂

[@ICE329]

sungaw sa Ilonggo, singaw sa Tagalog..hehehehe! 😀 ✌️

[@johnmariano9695]

Very informative

[@larry.dominick]

Learned something new and useful from watching this. 😁👍

[@ZT_Performance]

Your illustrations gave me a stroke.

[@speedlabchannel4452]

Happy heart attack

[@qxr20]

your a rt is as good as your theory.

[@MikeKleinsteuber]

Total drivel

[@ProfessorX1023]

Very informative