Subaru Boxer Rumble - Exhaust Explained

What gives the Subaru WRX STI its iconic boxer exhaust rumble? What's the difference between equal length headers and unequal length headers? What are the advantages of equal length headers? The reason the WRX STI sounds so unique is due to the unequal length headers. The exhaust pulses do not line up evenly before entering a single exhaust pipe to exit to the rear. The uneven exhaust pulses result in a fluttering sound rather than a smooth even exhaust note which is characteristic of equal length exhaust headers. This is very similar to crossplane crankshaft V8's versus flatplane crankshaft V8's, where flatplanes have a much smoother tone.
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[@Unb3arablePain]

Inefficiency never sounded better!

[@wizkid22]

+Joe Dijeaux Also quite efficient at kicking pistons through the block

[@dfw_motorrad1329]

+Steve Matchett Just about as efficient as any other engine if you treat it wrong. Ever notice the ones that spin a bearing or throw a rod are doing donuts or are really low on oil? Take care of it and it lasts forever. Or don't take care of it and it won't last long. True for any engine.

[@MrStlover99]

+Steve Matchett so does mazda and its not uel

[@bur2576]

+Unbearable Pain disconnect a plug on an older gti/gli with an exhaust and it sounds hilariously similar. SIMILAR.

[@BenjaminEsposti]

+Unbearable Pain LOL, like a screamin demon! (Detroit Diesel 2 stroke engine)

[@tokekkk]

Engineering Explained logo is actually a boxer engine.

[@Afeeq1011]

+tokekkk i never noticed that, i always noticed the logo shaped like a rotated gear shift gate..

[@EngineeringExplained]

+tokekkk Haha yesss!

[@SilverStackers]

+Engineering Explained secret is out, save the manuals!

[@StirlingMossDrives]

This diagram is wrong. Non turbo Subarus come stock with equal length headers. The only reason for unequal length headers is the other header/exhaust meeting to the turbo manifold on the right side on the engine. You're an idiot and don't even know your own car.

[@MikeG4936]

+Stirling Moss No - that's not the only reason for it. Subaru has sold the EJ series motor in Japan for years with EL headers... so if they wanted to go that route, they could.

[@LucaCarMods]

Best sound ever! You can hear a subie coming from a mile away!

[@islandmynigga5388]

word

[@bradswoodshop1937]

+Luca Car Mods no you can hear a twin turbo BB coming from a mile away though.

[@LucaCarMods]

+TeamLowLife Brad i meant recognize👍🏼

[@juancargts]

+Luca Car Mods Sounds weak compared to a VR6

[@brianoconnor8479]

Not as far as you can hear a honda coming your way!! haha!

[@markvicferrer]

Inline 4's have a tendency to sound like an angry bee in a tin can. I can appreciate the sound Subaru's make.

[@infure]

@Kenny Argueta Ventura that’s not true, just say you can’t afford an sti and move on

[@hook0076]

These videos are great! I'm a Mechanical Engineering student, I want to design forced induction systems, and watching these videos is a great 1,000ft view of all the different systems used in modern autos. (Not to mention I'm also a huge Subaru fan)

[@LisaAnn777]

It's been 7 years are you designing forced induction systems yet?

[@dlobom]

Main benefit of UEL: Sounds awesome

[@AlfonsoCajiao]

I´ve watched this video many times! This channel is great as one can come back to videos. Thanks for all the videos and the helpful info. I´m very motivated by the passion you put in all your videos. I'm now obsessed with the STI more than ever, that sound makes me want one very bad.

[@mrd9534]

Can you do a video on how Rich Piana is so naturally massive?

[@Jacksonskipslegday]

Rich Piano is my favorite natural musical instrument.

[@LordBelial665]

+Dominic Bradley Rich Pantera is my favorite 90's rock band

[@Curling_Rack]

oil

[@EngineeringExplained]

+Dominic Bradley Honestly I didn't know who this was so I googled it. After watching a few of his KZbin videos, I actually admire the way the guy thinks. Do you own research, do your own tests, learn about what's best for you, and do it. Forums are great, but they can often be misleading. Honestly all the same info applies just as well to car culture as it does bodybuilding.

[@1BlinkwithAngels82]

+Engineering Explained He puts out some great information in my opinion but people lately just like to make fun of him and his name in the comments of his videos now. I can't believe it's spread into a channel about car engineering/reviews.

[@p3l1k44n1]

How about rotary brap explained.

[@bwickham195]

+Jsp P5 Taunus I don't think science has an answer for rotary braaap yet ;-)

[@newtracetriad]

It's caused by porting the intakes.

[@p3l1k44n1]

Ben Wickham I want V4 burble explained.

[@fox10169]

because it's a 2 stroke lol

[@bwickham195]

Generic Name Felix Wankel cared.

[@majkutisusernameom]

Thanks. I always wanted to know how they get that awesome sound

[@mattiloponen92]

i was just thinking about this earlier today. i really like the way my impreza rumbles. thanks for the explanation.

[@puppydax]

Really love your videos! Watched a BUNCH of them on the STi and other cars you reviewed. Ended up with the STi, partly influenced with understanding more about it and driving it and your videos!

[@LuxxyHD]

I wish you where my science teacher at school 😂 cheers

[@numinous4789]

My Mazdaspeed 3 makes a similar sound, sort of a gurgling, because of our stock UEL exhaust manifolds. Sounds great!

[@Bones12x2]

+Zack Richmond Yeah, I've always thought that the MS3 had one of the most underrated exhaust notes. Especially with a nice quality aftermarket exhaust that isn't too loud.

[@1down5up426]

+Zack Richmond Yup, I always wondered why my friend's Speed3 sounded so rumbly. Makes more sense after this video

[@gooseknack]

You should hear an Volvo 140 series, with the B20, 2 litre, short stroke I4. They sounded as gurgly as the old Subaru. The motors were almost as oversquare too. The twin sidedraft carby models with the C cam(mildly lumpy, factory camshaft) sounded best!

[@lecoureurdesbois86]

Not as "UEL" as the Subaru but will a UEL design, I had a Mazdaspeed 3 gen 1, removed the two resonators, kept everything else stock, and I loved the sound! Had some drone but not too much, the sound was deep

[@CaneSugarCane]

Thanks for finally making an explanation of this Subaru sound that made sense. Been trying to figure it out for a year now, but the explanations usually didlle and get stuck on the firing order. Cleared that up with your explanation of the pressure fronts. Do some more car review videos. Either way looking forward to more good stuff from you man

[@pierrecomeau3737]

This is a good one. What I would like you to explain also is the science behind the change in exhaust note or tone between fresh and "broken-in" exhaust pipe/system and the different materials used for different systems.

[@sevenpointsixtwo]

I'll take a 15hp loss over sounding like any I4.

[@singert66]

true words

[@bcubed72]

Dual exhausts matter, too. It's like the difference between listening to "stereo" vs monaural.

[@oinkyaldritz4509]

@Jimbob and i would watch videos that actually cater to my interests. Go watch videos on v8's, moron.

[@TCPUDPATM]

OR don't drive a 4...

[@FusterIsBased]

Would you take ringlands over sounding like any I4? EL headers reduce the risk of failure because there's equal pressure on all cylinders.

[@ardalanshabestari3437]

you forgot to write G on the "unequal lenth headers"

[@WelshyAutomotive]

BMW Technicien atta boy eyes

[@SHARK1202X]

I actually rewatched the video to see that.

[@SonicCB]

The smile on your face when you mention the sound is great.

[@BubblewrapisJDM]

Best explanation by far on UEL and EL headers and the boxer rumble. I think it's funny when people complain that the new WRX doesn't have that boxer rumble and they should have kept UEL on it. But they don't realise that they would be sacrificing so much beneficial efficiency and power by trying to run UEL with a twin scroll turbo... Also, a Corolla can replicate the same exact sound as a Subaru if one of it's cylinders are blown. Look it up it's hella funny.

[@Thedthanes]

Could you do a video on the explanation of different types of turbocharging.... parallel turbochargers,twin scroll turbochargers,etc.

[@EngineeringExplained]

I have a whole playlist! :) kzbin.info/aero/PL08CEA57427415959

[@banpeinet]

So theoretically I should be able to make my Honda Civic rumble as wel if I add enough plumbing to the header? Mad! :D

[@banpeinet]

Haha! Thanks, that was awesome! :D I'm just wondering how many HP were lost in the rumble. ;)

[@DevanH87]

banpeinet on less built cars (stock heads/cams/turbo) there's maybe a 5-10whp difference. The benefits of the design though help the turbo spool quicker and it equalizes cylinder pressures/temperatures. On your NA honda, the power difference will probably be negligible.

[@Rome1017Lights]

you could but the exhaust wouldn't sound the same, it would be a higher pitch due to different exhaust piping size, and different bore and stroke sizes

[@peanutsz321]

+Rome1017 and becuase its a honda civic

[@aemravan]

+DevanH87 Any N/A application was suffer a lot more from inefficiency than a forced induction car. If he took the NA motor and introduced a poor header design the power loss would be much more significant than if the HP loss of an sit going to an equal length header

[@brucerogermorgan2388]

Yes, you've got it right on the button. I'm glad to see that I'm not the only person who knows how this works! Good one, dude.

[@MechRider89]

I'm making a set of unequal length headers for my dsm, I've always loved that unique trait from Subaru

[@LegacyIvyTerascale]

what about dual exhaust with 2 mainfolds ?

[@RazgrizNinjaEX8]

Too bad for my H6 with EL headers. At least it sounds brutal, though.

[@JustLiving305]

Bro I've been watching your videos for a while now and I've always thought you were just a 16-17 year old who REALLY knew his stuff on cars

[@ShellMartijn]

Best explanation ever, thanks!

[@Anomynous]

How come they fire one side first? Wouldn't it be better balanced if they had left and right alternate? Like for example 1-4-3-2?

[@SilentRazor1uk]

+Derrick Wyldstar, perhaps to increase crank life via power pulse flex/twisting on the crank, & torque twisting effects lessens the rocking couple at certain loading reactive frequencies, for other engine and additional components within/upon the engine (bay) area individual service lives as well.

[@whoknows1631]

He has the cylinder numbers wrong

[@TWRX_Chuck]

"I promise my car is not broken" - me to anyone who rides with me

[@Hexsyn]

"This is just what peak Subie sounds like" :p

[@AndrewTJackson]

that sound at the end made me shiver! :-)

[@paulcountyfazzer]

This is a good explanation. I came across this because of the ecoboost mustang 4 cylinder engine being criticised for it's normal 4 cylinder sound. I always wondered why the 4 cylinder Subaru engine sounds so good, almost like a V8. So to resemble this, you would have to produce two seperate exhaust manifolds with unequal lengths, but at the expense of power. I guess the power is more important to most! This would be difficult to achieve on an in line 4 turbo anyway, due to limited distance avaiaible between the cylinder exhaust outlets and the turbo. The turbo needs to be as close to the cylinder head as possible to avoid lag etc. On a V or boxer layout it would lend itself however.

[@treydaypnw]

man you have built quite the Channel! you have a crap load of subscribers. is content creating your full time job?

[@EngineeringExplained]

Yep. Creating crap loads of content for crap loads of people is the goal!

[@boxerliferz4678]

I really appreciate your work man. You the number one go to guy when I don't understand something about my car. I have a 2013 BRZ.

[@JamesRussoMillas]

DAT SOUND

[@KathyWeathersbeeSC]

I really like your channel, very informative. You know your stuff my man, thank you.

[@irockluculent961]

Dat sound is beautiful. Thanks for explaining it.

[@alphafort]

arent the boxer engines the best configuration? why arent they more popular? and what happened to that flat 12 testarossa engine?

[@SidewaysGts]

Oiling and balancing concerns. Take up more space in particular planes. More moving parts. Comparatively weigh more (2 heads, double the valve train goodness, etc). Yadda yadda. Best? No. different? Yes.

[@alphafort]

SidewaysGts ty. managed to get more info too.

[@ewiem4351]

Boxer has been used by Porsche for decades. That's not to say it's "best" for all but it works well in that application.

[@lodbldbol]

They usually cost more to maintain.

[@BlatentlyFakeName]

Actually I think the biggest factor is cost to manufacture. Inline engines are a LOT cheaper to produce. But there are a number of advantages to them. N/A boxer engines are very reliable for a start.

[@Brian-dd2df]

Could you explain why Subarus typically have higher torque than horsepower?

[@roskataqv]

+Brian Patrick Because they have forced induction, more air means more fuel = more torque, hp is a function of the torque

[@MyFavoriteDisease]

+Brian Patrick Since torque and power are measured in different units, this doesn't really make sense. It's like saying a bucket of water has more mass then temperature.

[@Brian-dd2df]

MyFavoriteDisease Thanks for not answering the question.

[@Brian-dd2df]

tjsavage711 Hey, thanks dude!

[@Jaime7188]

more torque can also come from how the engine gets it's displacement. bore x stroke = displacement. bigger bore combined with shorter stroke generally gives higher horsepower and allows the engine to rev higher. smaller bore and longer stroke creates more torque, but the engine can't rev as high.

[@unabashedindividualist6232]

you have one of the best channels on youtube... I'm sure you already knew that though.

[@181pottsy]

Another positive to the EL headers is that you can run the same timing both sides as with UEL the short side ends up running hot, and creating a scenario in which promotes detonation and thus ringland failures. Though you can just lower the timing per cylinder and avoid it that way. Killer B make absolutely amazing 'Holy' headers.

[@bryandoherty9399]

I would rather have equal length headers, I don't need the boxer rumble, i like it, but don't need it. I'd rather have the equal length so the turbo works better and has less lag

[@ColdBloodedMonsters]

+Bryan Doherty The question is, can you make them EL till they reach the turbo and UEL at some point after so you get the best of both worlds? Probably wont work, but I'd like to know more.

[@newgenerationisbg]

+Bryan Doherty At the RPM's your turbocharger is spooled up at, there is no measurable difference. At 3000 RPM you have each cylinder firing off 750 times per minute, or 12.5 times per second, so the turbo has no time to loose it's rotational speed, therefore, not losing any power. And realistically, you are only losing about 1-2 horsepower with the unequal length headers, less than the difference between air pressure and moisture caused by different weather.

[@Rome1017Lights]

+Psycho Fourseven that wouldn't work. you have already evened out the spacing so exhaust flow is constant. splitting the piping would just make half of that smooth flow take longer to travel.

[@Rome1017Lights]

+Newgenerationisbg you lose quite a bit of power. the average gain when going to equal length is between 10-15whp. that equates to up to 20hp at the crank

[@newgenerationisbg]

+Rome1017 Where did you get this info? When my friend went from UEL to EL headers on his 2.5XT forester, the gain was 5 or 6 WHP. That's less than 2.5% of the power of the car, and therefore pretty much useless. It's still a very quick car, but sounds like a straight 4 now, so he will soon be replacing them for "dat sound". Of course, there are people who would deem those 5-10HP as worth it, so they can do just that. To each their own, it's a free world after all.

[@williamgrand9724]

Why does exhaust make noise? is it the pressure of exhaust being pushed out? or is it the sound of the previous power stroke? and why does a smooth but raspy exhaust note sound so damn nice to my ears? lol

[@steffensarchet2090]

Because science

[@TaigaXZ]

There's like three ways your car makes noise: induction (intake manifold, throttle body), mechanical (camshafts, pistons, valvetrain, etc) and of course exhaust. It's a combination of these three things that make up the noise you hear. A cool way to hear only mechanical noise is under engine braking, when the injectors don't fire, and very little exhaust or induction noise is created. That sound is purely mechanical.

[@williamgrand9724]

Raptor That doesn't answer my question though...

[@Pakman332]

+William Grand It's basically the aftermath of a small explosion blowing through a metal pipe.

[@Darwinpasta]

+William Grand Sound is just pressure waves. The exhaust coming out of the engine into the exhaust system is a pressure wave which gets modified by the piping and whatever resonators/cats/mufflers happen to be part of it before being released out the back. The size of the pulses, the time between them, and again the shape of the piping determines what you hear and how loud it is. As for why it sounds good... something something Morgan Freeman?

[@voltron979]

Thanks for that very informative and very logical explanation..!

[@user-pz7ut2wg6g]

Cylinders are shown back to front (1 & 2 are at the front, 3 & 4 at the back), but apart from that pretty good. Gotta love the boxer rumble!!

[@Joey_Bananas]

wait. so does that mean the iconic Subaru sound will be gone with EL headers?

[@TheNiggiboy]

+Joe Espo yes sadly :(

[@DevanH87]

+Joe Espo equal length on a subaru doesn't sound like a honda by any means.

[@DevanH87]

+semiautoriflelover1 they have equal length because they are twin scroll. More efficient at making power and spools the turbo much faster.

[@Rome1017Lights]

look at the wrx, it's already gone

[@Rome1017Lights]

+semiautoriflelover1 they have twin scroll turbos. 2 cyls feed half the turbine and the other 2 feed the other half, to make it simple. equal lenght are needed to do this, more efficient turbo design

[@alanmartinez488]

The sound is similar to an air cooled VW 4 cyl.

[@jacobfleming565]

Cause its a flat four

[@heatice77]

Thank you for explaining it so well, easy to understand and honestly my 2015 WRX with an aftermarket exhaust (as I hear online, mine specifically does has the stock) can sound just as sexy so the positives for equal length outweigh the mainly cosmetic (can I use that with sound? lol) or audible benefits of the unequal length headers.

[@SweazyRaskal]

Your videos are good but your drawings are even better, Thanks for the info!!!

[@EngineeringExplained]

+SweazyRaskal Haha this time was just rectangles and lines, that I can handle. Glad you enjoyed the video!

[@SweazyRaskal]

i really appreciate the time you take to reply back to your fans...thanks my friend cant wait for you to hit 1 million subs!

[@3mfreale]

Can you put UEL Headers on the WRX?

[@EngineeringExplained]

+Alex Frey It's probably possible, but you need to remember it's a twin-scroll turbo which uses the exhaust pulses from pairs of cylinders, and by changing the length you change the effectiveness of the turbo. I certainly would not recommend it: kzbin.info/www/bejne/imithYWIobh4j6s

[@DevanH87]

+Alex Frey, yeah you don't want to give up that quick spool just for sound!

[@MTBDojoMTB]

"But will it fit my Honda?" ... I wonder how many will get the reference?

[@bigjune4899]

Awesome video, please continue to educate us!

[@Riez_00]

I now when a Subaru is coming just by sound I don’t even need to think or look, it’s amazing

[@Skassa-garage]

Subaru cylinder layout is Wrong😉 the engine is the Wrong Way or the exhaust is not going to the rear but out the front 😔

[@markg7030]

+MrTurbotoys I agree something sounds wrong on a Subaru. An old air cooled VW has the same engine configuration and sounds great.

[@leohughes6921]

+MrTurbotoys I was just thinking this. Cylinders 1 and 3 are on the passenger side of the vehicle and have the short exhaust runners. Great video with a good explanation though. No offense to Engineering Explained

[@squirlesg2228]

I think the drawing was more for the purpose of explaining the concept of unequal and equal length headers and how they affect exhaust, not to give a detailed blueprint of the car's engine map. I know that's hard for some people's tiny brain to understand.

[@fahrvergnuugen]

+MrTurbotoys It depends on if you are looking at it from the top or the bottom!

[@So0nerMag1c]

fahrvergnuugen no it doesn't, the exhaust runs toward the back(well up to the uppipe-turbo- etc) but cylinder 1 and 2 are the front 2 cylinders therefore top or bottom it would still run the opposite way he has it drawn. He didn't draw a blueprint though he's just making a crude drawing to explain the exhaust

[@3ne2nr4life]

I loved this video because I'm a Subaru junkie and I own a n 04' Wrx Sti

[@6pot]

Very good explanation! although it would be nice having a clip of a boxer with equal lenght headers, to compare the sounds!

[@Strakos0]

YES SOMEONE GOT THAT IDEA (to make a video explanation) TOO!!! I AM NOT ALONE And thank you for the sound

[@BenjamanWoolner]

Great video, I'd like to see a video on the awesome sounds of the Audi 5 cylinders and that of the VW R32/36 which all sound amazing. How much of the sound is derived from the engine vs the exhaust

[@kenrobinson1099]

Nothing like owning a car with an engine that sounds like it has at lease one cylinder that isn't firing and is prone to problems with its own rotating mass... BRILLIANT!

[@extremejoy]

Always loved that boxer rumble...

[@bensiok]

thanks, always love your vids!

[@MrTimstaaa]

Hi Jason. Over the years I've heard many a debate from many people about the differences between a straight 6 engine compared to a V6 engine such as which one makes more torque at lower revs and which one revs quicker and harder and which one is more fuel efficient. Would it be possible to make such a vdo describing the advantages and disadvantages between the two of them ?

[@Vlican]

Love that iconic boxer rumble. I'll gladly trade some power and efficiency for dat sound. I had an aftermarket UEL on my N/A 2.5L back when I owned a Subaru Legacy LOL.

[@ethanheikens5705]

Glad to see one of the old whiteboard videos! So is the boxer sound produced purely from the UEL? If this is the case, would another engine, like a V type, be able to make the same sound if they had the same exhaust configuration? I'm wondering if the sound is unique because of the exhaust or a combination of the exhaust and the engine itself.

[@michaelzarate3832]

i have EL headers the rumble is still there its just more cleaned up and more WRC sounding also its important to note that your Up Pipe and down pipe and even exhaust shape and diameters all play a role in the acoustics of your exhaust

[@JohnmillerPowerlifting]

I would love a video on heat wrapping your headed and what are the ture benefits of doing it

[@muaythai193]

Crossplane V8 and the Subaru boxer are my favourite engines.

[@MelC-bx9ny]

It sounds nice, i wonder why does the frs, brz and 86 have such a horrible torque dip? Great videos man this is my 3rd time rewatching this vid, keep up the great work !! 👍🏼

[@BushCampingTools]

Great just answered my question to u on a earlier video.

[@seanottaway1615]

Recently bought a 2009 Outback Sport 5MT, not very fast but it sounds beautiful.

[@rka1916]

Cool video, do you have a video explaining when people upgrade their cams (to GSC S2 specifically) and why the exhaust sounds different?

[@StingrayOfficial]

I love this video. I recently saw a Miata with UELH and it sounded just like a subi.. so strange!

[@gooseknack]

The equal length headers were known as "Extractors" in Australia(possibly else where too).. also heard it referred to as "tuned headers" or "tuned exhaust" at some point. Extractors were fitted mostly to improve fuel economy more than anything back in my youth. They did make some difference. Like with not tuned headers, they had the advantage of removing heat away from the cylinder head more rapidly too than the cast iron manifolds could. Not sure how much of a difference it made for standard road use though..... There was the performance improvements that could be had too from the fitting of extractors.

[@BiologistRyan]

tuned exhaust at least to me typically referred to 2cycle rc engines where it really mattered significantly more.

[@jdmeaux]

Love that sound.

[@ak540i2]

An idea for another video: Exhaust back pressure vs scavenging. What helps scavenge/back pressure and what doesn't. How to calculate exhaust tube diameter for engine size/power for optimal exhaust gas speed.

[@carlosle3164]

Thanks for the explanation

[@derekobidowski7574]

The vintage VW air-cooled engines used in the Beetle, Karmann Ghia, Type3, the type 2 bus and the vanagon from 1983-1992 which is a waterboxer all produced the boxer rumble depending on the exhaust system used. as the Subaru engines are a popular conversion for the water cooled vanagons, as the early vanagons from 1980-1983 were air-cooled.

[@KrOnIc343]

Hopefully this will be in the aftermarket scene soon

[@korbinstarkey4554]

Very well explained, if I this were a restaurant i would time you a blue bill.

[@MrNicholg]

My 93 Probe GT with the Mazda K 60-degree 2.5L V6 sounded like silk thanks to funky equal length fingers underneath the block that forced the oil pan into a pretzel.

[@DoriSirius]

Great video! What about the effects of uel and El on a supercharger? Thanks!

[@colbyw917]

I had a basic idea of boxer exhaust but this gave a way clearer understanding of the science behind it. I have one question, I’m looking to get a Subaru for a daily and trying to figure which one would be best. I’ve looked anywhere from a 90’s RS coupe, 02’ Impreza outback sport, or a simple Impreza sedan. I’m going to do al rally build etc.

[@rayleal2109]

great explanation!

[@oxidizedolive]

I hooked this video up to my trucks Bluetooth so I could hear that heavenly rumble in HD 😂🔥

[@LostInPhilly89]

I'll take the rumble of my '14 WRX over the whine of the new ones any day of the week! Are the ELHs a better design choice as far as power goes? Yes, I cannot deny that. But, there's more to driving/owning a car than performance and numbers. I would much rather drive a car that I actually enjoy the sight and sound of than one with slightly increased performance. Anyway, great explanation as always! Keep the information coming!

[@dominicfong6341]

Thank you for explaining! So it is possible to have the exhaust note of a flat four to sound exactly as its inline counterpart. Also why Subaru flat engines seems to be inherently suffering from higher NVH?

[@sfbmx88]

Would it be possible to replicate that sound in an inline 4? Looks like each banks exhaust runners aren’t connected to their companion cylinders. I know there’s more downsides than advantages, but it would be interesting to hear.

[@madduck692002]

Thanks Mr Engineer

[@david0608]

learn a lot ,thanks.

[@mrPauljacob]

learned one more thing. thanks.

[@robertstiffler1251]

Are equal length headers always desirable? For example on a parallel twin or other configuration with an odd firing order, would having equal length headers be best?

[@chrisjovner144]

Is there any benefits from having UEL headers compared to EL headers on a N/A engine?

[@alish6356]

i love my boxer rumble! Subarus are very affordable and generally reliable and very fun to drive.

[@paulmarsdensr1095]

A great video. my question is for my Base model 2020 WRX/ STI. Does my base model WRX/STI have equal length headers or unequal length headers? My other question is does the 2020 STI have an EJ25 motor or an EJ 20 motor?. Thank you 😊

[@ColinCren]

I always wondered about that!

[@alexmoore5970]

Jason, I know this is an old video but I have a question involving the FA20 motor in the BRZ. I was told UEL headers cause lean conditions in the EJ series such as the current STI, but the computer electronics compensate for this by sensing the air to fuel ratio, resulting in a rich condition. My question is, if I install an AVO turbo that contains UEL headers for my BRZ with their provided engine management system, do I runt he risk of leaning out one of my cylinders?

[@nobodynobody3903]

Can you tell me why boxer/flat engines need more fuel than straight engines? Thanks Greetz from Switzerland

[@RIco02225]

Hey man! Im hoping you can validate this questions with some science. What if for the equal length header car, you were to add a delay/bypass pipe somewhere along the exhaust ( after the turbo) to create a similar note beacaus of the coliding pulses? Thanks!

[@bearatts]

I think your definition of sounding phenomenal is vastly different than mine.

[@mistgate]

It's possible to get dat rumble (albiet, not as intense) with equal length headers. Using a 4-2-1 collector setup instead of a 4-1 collector setup seems to preserve the rumble more. I had guys ask what headers I was running on my RS when all I had was a 3" catback on stock headers, which have the 4-2-1 collector setup. I still have rumble with my 2.25" catback, too, it's just quieter overall. Most aftermarket EL headers have the 4-1 collector pattern. I'm planning on getting the TechWorks Engineering 4-2-1 headers hopefully by the end of next summer, so I'll find out for sure if EL can still have good rumble.

[@George-lr4sm]

Any suggested for overall good tone good horsepower for the regular 2017 wrx? Having difficulty choosing. Thanks!