This will make YOUR exhaust sound AMAZING. Custom exhaust builders share fabrication secret!

[@geekers8644]

That exhaust sounds more like a Hellcat than an actual hellcat. What a demonic scream that things got. That exhaust fits that engine perfectly! Amazing work

[@JoeIsCrazyWillman]

Not even close. You must be listening to SXT and GT package challengers and chargers with hellcat badging on em. Those guys like to up badge their crap and think they're fooling people

[@WZ16A]

I don't think you've ever heard a hellcat

[@geekers8644]

@@WZ16A I just mean that If anything, the scream this car makes sounds more like a cat from hell than an actual hell cat. Much more deserving of the title.

[@CaptainCurt07]

*Sounds terrible!*

[@PS3TEKKENLORD]

I want my engine and exhaust to sound like a early 2000s FORMULA 1 RACE CAR and sound of the LEXUS LFA ISN'T BAD AT ALL😁

[@MikeandZanaWhittaker]

Bro looks like Ned Flanders if he never married Maud, never had kids and bought a GTR

[@n8v-t-800]

😅😂

[@lazylion420]

great reference 👌

[@derekhobbs1102]

Diddly

[@dogdue4588]

😂😂😂

[@dogdue4588]

Okilly dokilly...

[@ryanjohnson9325]

That mustache tells me everything I need to know about this man. He knows his shit and earned that stache.

[@bilaltariq7819]

Having made a few DIY exhausts on my driveway with the car on jackstands, I know how much work goes into it and how tricky it can be to get it all done perfectly. You guys are very inspirational

[@bmint]

I made my seabird sound like a 2 stroke.. Replace resonator with glasspack, install Flow tech raptor with a farm flapper and add some very poor welds.. Boom you have a two stroke sound

[@ericharrison619]

Expansion chambers are what we always called them. Been a thing on 2 strokes since the late 70s. You explain them quite well.

[@Thats_X_]

This the comment was I looking for.

[@beaches2mountains230]

YES BUT THEY MAKE AN EVEN HUGER DIFFERENCE ON 2 STROKES COMPARED TO 4 STROKES !

[@tonypate9174]

"late 70s" Care for 50/50 or phone a friend on that one , Maybe ask "Deek" ?

[@sn4rl277]

Imagine buying a $120,000 v12 sport car and it sound like a Toyota Avalon.

[@ajsmith7018]

the thing is he bought a 120,000 v12 luxury car

[@williamparker7823]

It's an S class. It's meant to be quiet and smooth, even on the amg ones.

[@WZ16A]

Turbo v12s almost never sound good

[@hasancanaydar835]

s in ''s class'' isn't for sport

[@dominicbloom7528]

Doesn’t drive or feel like one though😂

[@BoostedCruze]

I haven't been to school in 20 years. Watching this video felt like the first day off school. I'll be watching this video 3xs a week . Great video

[@ky1699]

Dude is BRILLIANT yet refreshing in a sense that those I’ve met who purport brilliance try and convince you they’re just that, seemingly always breaching that condescendence. O.J. obviously strives to teach and does so in a humbled manner. Cheers to O.J. and his FMU family-literally his family!

[@FluidMotorUnion]

When you work hard on a video to try and convey that all the fancy engineering on earth isn’t more important than actually building something to see how it turns out… comments like this mean a lot. Thanks. I’m just trying to get people to understand while you can calculate these things into precision with unlimited time and money… you can also just try it out with a few guidelines and get great results. Totally attainable for most geahreads without a degree, so don’t get intimidated by those who say otherwise! Appreciate this.

[@getahanddown]

@@FluidMotorUnion Hi. DIY car and audio guy here. To help you ballpark your tone I would use a 1/4 wave resonance formula to measure the pipe length for a specific wavelength / tone

[@billbonu1639]

You know how you can tell if someone is an engineer? they'll tell you.40-50 times usually.

[@DVJiMATT]

In a humbled manner? Seems to me like it was in a fishing for that Pat on his back manner. So egotistical or at least seeking recognition to be able to flex ego with our it being arrogant.

[@ky1699]

@@DVJiMATT You seem like a nice guy. Cheers.

[@misc_]

"brands of oil to never use in your engine" 😂😂

[@therealboofighter]

This one trick mechanics don’t want you to know?

[@FZERO20]

I was just about to comment this!!!😂😂😂

[@StevenTanner-oh2ef]

The oil geek on YT can help you with your question.

[@killendeezhoes]

1) vegetable oil

[@GCRTeamPortugal]

Liquid Moly 🤘🏽🤘🏽🤘🏽

[@falcorthewonderdog2758]

I had a 67 lemans with a Pontiac 350 with cherry bomb glass pac dual exhaust. This was the 1980s. The previous owner welded 3/4 inch washers in the tailpipes about 10 inches from the tip. The washers created a whistle sound at about 2500 to 3000 rpms. People always asked if I had some supercharger or turbo in it.

[@HeidiFegles]

This is why a triumph motorcycle sounds so good it’s the cone exhaust that all the flat trackers run.

[@andrewslagle1974]

It is also the crank design and engine design .Like a mustang gt500 with the flat plain crank .Hell even a base 5.0 GT sounds killer. The 4.6 3 valve mustangs sound amazing!

[@flinch622]

The basic exhaust note begins with the cylinder head.

[@jmetalsmith1362]

The firing order.

[@cube9519]

@@jmetalsmith1362 Doesnt really matter but also it kinda matters, only reason why firing order would matter would be some (as an example) of the V8 engines firing 2 cylinders on one side right after each other, but this can be smoothed out by adjusting runner lengths and you can also see the effect of adjusting the runner length on dyno as few extra ponies in most of the cases. Equal length isnt the thing, its getting the exhaust pulses out at equal time and hopefully in equal velocity.

[@THESLlCK]

@@andrewslagle1974 it's striking how much info you got wrong

[@drotegu6]

Megaphones obviously made a difference. Early in the video "truck exhaust" was mentioned and I believe not positively. If I had to give a one word description of how this exhaust ended up sounding was like a truck, maybe the best sounding truck but still a truck. Like a big block with big cams not a Pagani exotic or exotic in general. Regardless of the result the information packed in this video is excellent and really appreciate the detailed breakdown.

[@JoeIsCrazyWillman]

Yeah, you're not gonna get short length quad exhaust sound from a long length dual exhaust.

[@superspeeder]

Agreed. This thing sounds like a truck. Unbecoming for an S-Class.

[@firstname-qq3xp]

My thought exactly. It still sounds like a truck, just a beefed up one.

[@morganmenser6773]

Big blocks only have one cam lmao.

[@JRADMAKES]

It took me 13 minutes to realize this is mark rebillet’s older, smarter brother. In all seriousness, thanks for explaining things in the way you do 👍

[@BrianHamilton-nv5jk]

Good call… I was sitting here thinking why does this guy remind me of somebody? I saw that dude live. He is a fun time.

[@rubyred93chev]

_What a difference OJ, kind of like hitting the bricks in the gym. The more you structure your workouts(and yes to some, increasing the weight), the better the outcome(insert: OJ Lopez's physique). Hence, the more you fine-tune your 'custom' exhaust, the better your baby is going to sound(and yes increasing horsepower along the way). Side note: your delivery is getting more natural for the camera, damn good job all the way around._

[@LegitStreetCars]

Congrats on the big 30k subs! Here's to a million more!

[@canoezzz]

@LegitStreetCars Maybe this video is a sign to get megaphones on your CL65 😃

[@pormansgoldpmg5493]

Samcrac said he can build u a custom exhaust for the custom supercharged AMG using tin snips, jb weld, dryer vent tubing, coat hangers, zip ties and a trumpet he found at Goodwill for a whole lot less than what this fancing talking city slicker will charge u.

[@peterflynn889]

As an automotive engineer I can confirm all you said. Well explained.

[@FluidMotorUnion]

thanks for that professional vote of confidence

[@sniperpronerfmods9811]

OJ i take back my mean and negative comment on the last aventador video... You did a great job bring out the sound on this one!

[@FluidMotorUnion]

I liked the comment!!! But we didn’t build that one for sound first was my main point. If we did, it would have been a different plan of attack. The goal was to try to affect a performance vector I think no one else had taken advantage of- the sound was questionable because we had never done it, but optimising scavenging via order, would only benefit?!? So it was kinda let’s try THAT and see how it turns out. But it made power so mission accomplished! Happy to still have your vote of confidence on our ability to massage out good sound, it’s just two different goals.

[@shodancat1000]

i love that you guys focus on tone and sound quality as much as you do performance/flow. i might have to take my Thunderbird SC with a custom single turbo setup to you guys to see what you can do with another infamously truck-ish sounding engine, the Ford 3.8/4.2 V6

[@FluidMotorUnion]

We’re ready when you are!

[@02SLERA]

96 Thunderbird V6 was my first car, I’d love to see what you’re doing with your super coupe

[@OGYELLOW]

Wow. The education here is unmatched. Well done!🎉

[@billbonu1639]

You can overthink anything.

[@fobbitoperator3620]

This channel melds gearhead knowhow, with the intricate disciplines of raw science. Your oratory presentation was quite polished, & professionally articulated. Great video!

[@FluidMotorUnion]

Thanks for the view

[@canoezzz]

Amazing work OJ, usually these videos don't keep me engaged but your diction and knowledge are unparalleled. Keep doing what you're doing.

[@turboflush]

Just changing the outlet tip can make a difference. I have a 2000 silverado with flowmasters. It had dual 2.25 outlets. Changing them to an oval changed the tone. Megaphone of a sort.

[@tommys2979]

Ditch the flowdisasters and get some straight thru style mufflers. Sounds way better

[@ALCRAN2010]

​@@tommys2979, recommendations?

[@Rocamellion]

This was a really interesting discussion of the concepts behind exhaust systems.

[@danieldimitri6133]

Just a few notes... The results you got are great 👍. As a muscle car guy I was afraid of it sounding like an open wheel indy/f1 being that it would have even firing banks and so many cylinders. This is actually better than what I was expecting. But if you wanted an exotic f1 sound or to harmonic tune the engine it would be easy without megaphones which the math of those seems to be a guarded secret. On 2 strokes they are often regarded as sound wave reflectors but when glossed over in automotive exhaust literature they talk about sound wave timings extensively but then some may say megaphones don't follow the same mathematical model and require testing. Not sure why that would be but darin Morgan who designs intake systems that also use sound wave reflections talks about angles as part of the rpm range so perhaps the reflections aren't a function of the average length to the cone and just happen when acoustic impedance sufficiently changes so I don't have enough acoustic knowledge to speak on that. But I do know how you would typically tune collector extensions and primary header pipes when megaphones are not involved. Sometimes the path to the best x or H pipe placement is blocked but because it's harmonic there may be subsequent locations down stream. These down stream locations may be lower in pitch so if an f1 type sound is desired you may need to pinch a harmonic (ask a guitar player about string harmonics) to make it high in pitch if you so wanted to. To do this you could add a stepped pipe or an H or x at a half or third or quarter point in the path getting to the tuned point. A typical location for a x would be around 33" behind the end of the primary header pipes for a 6500 rpm engine, it depends a bit on gas speed (the back wave might be delayed in time more than the forward wave time is decreased by gas flow changing the exact length a bit from standard organ pipe math) and temperature. But if that's obstructed by the transmission or transfer case or cross member you could go around 67" with an H at 33" or 16.5." the x on many cars would actually be better placed near the rear universal than as soon as it fits by this math. Shorter for an 8000rpm engine and longer for a 5000 rpm engine like a stock cam or a long runner efi manifold like Ford and Chevy used in the 1980's on tpi and 5.0/5.8l engines. Those numbers are for 8 cylinder engines, the numbers for 12 cylinders may be shorter. The more pitch you want you would divide the distance to the x by larger whole numbers for additional reflection points. A guy who built a 5.0 Ford (yes classic 5.0 not Coyote) powered BMW for budget racing built a 180 degree header to get equal pulses and a super car sound. It worked but this type of build often forces you into primary pipes that are too long. It might work on a 5.0 because the intake is also very long. But it's not always best. So he then replaced the hand built headers with equal tuned length headers and used a triple x pipe to get the super car sound. So he had a pushrod V8 with odd firing banks not known for that high pitched howl and extracted that sound from it on a full length sedan simply by pinching harmonics using redundant x pipes ! Long pipes tend to mean lower pitched rumble but it can be manipulated easily by causing intentional reflections at equal interval lengths.

[@goldar4846]

Awesome info. Is there a source I can read into this more on?

[@morganmenser6773]

Awesome comment! Where can I find a video sound clip for this BMW?! I would love to do triple X pipe on my C5 corvette.

[@francesco461]

Correct me if I'm wrong but 1" of exhaust diameter for every 100hp sounds like it has to be incorrect. The area of a circle grows quadratically. so a 2" circle has an area of 3.14 square inches but a 4" circle has an area of 12.56 square inches. Just speculatively the flow demand for horsepower has got to be linear. Sounds like you'd lose scavenging effect very quickly. Also doesn't match engine dyno results I've seen on Richard Holdener's channel.

[@riccello]

You are absolutely correct.

[@killroy2993]

That 1"/HP. Will also depend on displacement. A 7l engine making 300hp will benefit more from a 300hp 1.5 with a 3". Let alone V engines with dual exhaust. Or split headers

[@Fluffylives]

Literally says “this is not the best way”

[@FluidMotorUnion]

You build 700 + systems and this applies to 3/4 of them, it hard not to recommend this to most of the people watching…

[@Sammy_q50s]

There's a table I saw with displacement figures to help with he ratios

[@DragonKingNate123]

19:00 As soon as the no megaphone dyno pull was done I audibly said “holy fuck” LMFAO

[@perkypears]

the sound difference is CRAZY

[@spyplane8]

Anyone who understands anything about sound waves or even built a custom tuned subwoofer box should be able to understand what the diameter and the length of that vent can do to the sound.

[@desparky]

Years ago I had a 5.0L V8 with a single 2½" pipe. It had an expansion chamber near the transmission (very similar to a Catalytic converter that had it's insides removed), then a straight through pipe through to a rear muffler. It sounded OK, but I started experimenting and hole sawed another hole next to the muffler tailpipe into the Helmhertz chamber at the back of the muffler. This hole lined up with the internal perforated pipe inside the muffler, and I inserted another short pipe into the hole and attached it to the existing tailpipe with hose clamps so that it could be adjusted to insert into the muffler chamber by different amounts. My mate and I took turns driving WOT and the other listening as we drove by. We adjusted the length of the new tailpipe until we got the best sound, then welded it in place. The results were amazing. Not super loud but more like a sub woofer effect, especially at idle. I guess it may be due to two out of phase sounds being produced? Strangely blocking either pipe had the same effect at making it quiet to about the same noise level. I had many people ask me who built the exhaust. So my question to @FluidMotorUnion is, have you tried placing the megaphones in each pipe at different locations to each other. ie, one close to the engine and one further to the rear. Or, placing them at close to the same length, but making a sliding connection on one so you can adjust it along the pipe by a few inches and move it slightly to experiment with different positions along the pipe while ethe other one remains in the same place. Please tag me if you try this, as I would be very interested... even though my revhead days are pretty much behind me.

[@cody0006]

You should make a video on your explanation brother thats smart af

[@desparky]

@@cody0006 Unfortunately the car was sold many years ago. My only car I have with a V8 has a lovely factory Stainless exhaust that I don't want to hack apart. I've been tempted though.

[@gregz4249]

Sounds like a trombone effect

[@MichaelSPalmer]

Probably the best sounding Merc v12 Biturbo I’ve ever heard.

[@MegaPixie666]

The best sounding one on KZbin is Effspot's old v12 merc imported from Japan. It sounds like a Ferrari v12. It custom headers by some Guru in Japan.

[@FluidMotorUnion]

@MegaPixie666 who built his lambo exhaust?

[@MegaPixie666]

I don't know, probably yourself

[@jlnade1851]

Not a biturbo tho​@@MegaPixie666

[@UKBUILT]

😎👍

[@orange2352]

Let’s goooooooo. Alex better have gotten his push ups in!!!

[@FluidMotorUnion]

Screenshot’d this comment to bully him with 🤣

[@orange2352]

@@FluidMotorUnion haha nice!!!

[@gEtar87]

Fantastic video! Ever since tuning 2 strokes with expansion chambers, i always wondered why there wasnt more exhaust tuning for 4 strokes... scavenging, pulses and waves have to account for something.

[@Scandinavian_Pride]

I was told my the local muffler shop that I could NOT get true dual exhaust on my 2000 Honda Accord sedan 3.0L. So I'm considering putting the J pipe exhaust on her.... Good, bad or it won't make a difference in performance?? Great upload! I wonder how the "megaphone" would sound on the vtec v6 Honda? I replaced the stock mufflers with flow masters with much bigger tailpipes. It does NOT have that raspy or crackling sound. It actually has a much deeper sound.... I was happily surprised too!! I can't stand that straight pipe crackle PERIOD! haha

[@bunky8077]

That original exhaust it came to you with is shocking for a car worth that much! Mild steel, crush bends and mig wire hanging out. I would be embarrassed giving that back to a customer. Fine on a 25+ old car but not on that

[@FluidMotorUnion]

It’s way more common than you think. Although, our view is skewed because we are known as a place that will fix your bad sounding exhaust choices… so maybe that’s why WE see them so often?

[@AtlanticBuilt]

It's crazy what stuff comes with. Even quarter million dollar + cars come with the MIG goobers nowadays lol

[@getahanddown]

It is subpar by Mercedes. That price, spec level and performance they should at least look good. Carry on what they had going from the headers, mandrel bent 3" stainless-ish pipe isn't going to break the bank

[@HeidiFegles]

People who think they can weld should be given a weld test before continuing on the exhaust

[@killendeezhoes]

⁠@@HeidiFeglesfuck it we learning

[@mxracinguy5993]

This guys is clearly very smart. He even follows the rule of thumb of having one inch of moustache per 100 IQ points. This was very informative. Wish you did a segment on how to add megaphones to sportsbikes.

[@FluidMotorUnion]

I'll keep that in mind for future videos! Maybe a custom megaphone build is in order.

[@mxracinguy5993]

@@FluidMotorUnion Cool, with your expertise I'm sure you'd achieve an answer whether it's a win or a fail. Of course space on a bike is limited and no one wants to see long pipes sticking out. But if a megaphone could be compact enough and still achieve respectable results, you'd have a whole new clientele lining up the door. Looking forward to your future experimentations.

[@ssoffshore5111]

Interesting concept using the megaphones. I'd love to see this tried on an already great sounding NA engine, like a LS7. It would also be interesting to try using the megaphone and reducer going into and out of a high-flow cat system. That might flow better with a smoother transition into the inlet side/face of the cat, and the cat would tend to straighten the flow/soundwaves, before reducing back to a traditional pipe side. Only concern might be getting the cats close enough to the engine with the megaphone... But using the C6Z example I mentioned, I think one could place them in the early part of the tunnel with success. Could be interesting to experiment with!

[@slick408]

I have a c6z & kooks with their high flows. Check out HJS catalytic converters. They make what u want, no experience myself but I heard they the best.

[@fransb8543]

Having witnessed the result of your efforts on Alex's LS swapped 911, I'm more than convinced of what you guys are capable of. That thing sounds absolutely venomous.

[@spezzy]

Sounds much better than my S65 did. Would like to see you guys test the Brilliant Exhaust merge pipe on these as well. Same style merge that Gintani made popular on Aventador.

[@dot_boi]

Great video! I'm more of a DIYer, this gives me a couple ideas to maybe mess around with. I've played around with a Helmholtz or 1/4 wave resonator. I fabricated two telescoping pipes T'ed 90 deg off and capped closed, uses clamps to seal it for testing. I played around with different lengths which changed the sound and you could get a narrow "scoop" in frequency depending on the length. Its best to build a solid one once you figure out roughly what length you want first.. I tried to pick out some drone areas, while not completely removed, it definitely helped remove drone and changed the sound in a little bit of its own way. Have you guys made one before?

[@bigtsperspective5831]

Factory exhaust is cheap ,is restricted and lacking a good sound. However the entire reasons for factory exhaust is to meet production cost , epa standards and federal dot safety standards. It’s not that they don’t care it’s that they have only so much room legally to get 600 horsepower on to the highway. Like a hand gun . Can’t buy it with the extended mag . That’s a customer option 😉

[@j.cannon2021]

Yep that's pretty much what the guy said

[@WZ16A]

First time I've heard one of these turbo v12s that don't sound mediocre, really cool video, the NA m120s that Mercedes and pagani used to use sounded divine

[@UKBUILT]

I am using an M120 on my V12 build 😎👍

[@ThePete2432]

24v Vr6 vw is still one of my favorite sounding cars

[@aluminumfalcon552]

Yes, that and the Audi 2.5 5-cylinder. #1 and #2, you pick the order.

[@richardgoldschrafe4747]

I agree, And I get to drive one every day.

[@jeffreymichael4294]

Came home in an uber to find the brake lights on in my 2003 maxima. Same problem. Rubber pad was laying on the floormat. Found a Dorman replacement p/n 74025 at autozone for 9.99. Fixed the brake lights AND the one on the cruise switch was gone too. Cruise had not worked for 3 months. Now that works too. Both pads in the box for $10.

[@TommyPickIes]

It sounds like a dragon now.

[@FluidMotorUnion]

Once we install the larger turbos and dial in the tune maybe it'll breath fire as well ;)

[@HeidiFegles]

My Subaru has 2 mega phones on 1 pipe the expansion chamber for a 4 stroke or the power bomb in the fmf world but this is the key to tuning your exhaust tone

[@williamrgrant]

You know you are in the 21st century when a garage shop video about exhaust delves into FEA and the physics of pressure pulse scavenging. Wonderful discussion. That thing sounds insane now.

[@teamairsoft1005]

Thanks for the advice on my corvette! I appreciate the sheer amount of knowledge you have on fine tuning these exhaust systems and I especially appreciate you taking the time to share it with me.

[@mreroot]

I've used megaphones in a couple.of builds. Actually used two to build a tailpipe on my 16 wrx. Used 1/4 inch rod every 90° on the outside, counter sink holes drilled through in a helix pattern. It was then inserted in the outter cone and I cut exposed section the inner cone roughly halfway between it's end and the end of the outter cone. It was finished with a 45° cap and mounted about 45° out from facing down. It was an expansion from 3inch to 5inch. It turned out exactly as intended too, deepening the tone, cutting engine noise and allowing the turbo noise to be more pronounced.

[@aluminumfalcon552]

FMU: we’re telling you our secret because the only way you’re going to be successful with it is if you have all the equipment, resources and experience we have. The car sounds great by the way

[@tnc4700]

using 2-stroke rules to improve a 4-stroke... i like it!!!

[@Richard-n2w1g]

This is called scavenging in a 4-stroke. A 2-stroke relies on that resonance to perform as intended. A 4-stroke is improved by using it

[@tnc4700]

@@Richard-n2w1g exactly

[@halrichard1969]

Mr O. J. , Right away i sensed where you were going with the exhaust pulsing, backpressure, and evac efficiency. What cracked me up was that the presentation might have been served up by a professor in a tweed suit standing in front of a chalk board. And, here we are getting exhaust nerd education from a guy with a Hidden Body Builder in that jump suit presenting as your everyday mechanic, which you most certainly are. Well done sir, well done. I enjoyed your very clear and detailed explain of what it is you do. Thanks for this Video. :D

[@FluidMotorUnion]

Order megaphones pre-built by yours truly here: fluidmotorunion.com/product/exhaust-megaphone/

[@KSenhor]

On a NA car should this be installed after or before the ressonator?

[@Mortarman0341]

Love your content

[@diztroy1]

Thanks for offering these, looking forward to experimenting! Your website says both megaphone and megaphones (plural) in the description , so it's not clear to me if they come in pairs or a single megaphone when I try to buy, may want to say "single" or "pair" explicitly. Also, have you experimented with one on a turbo 5 cylinder like a TTRS 2.5T?

[@andregroves7640]

Great editorial. Thanks

[@VerrueckterKerl85]

maybe that‘s exactly what i asked for in my Corvette. a deeper, more throaty mean sound. i‘ll give it a try.

[@mr.shazam2739]

Jaw dropped when you revealed the exhaust with megaphones. Amazing work!!

[@chrispalubeskie3256]

use glass packs and turbo mufflers it will sound amazing, with a NA motor dont use more than 2 3/4 pipe or it will cost you in hp. 3 inch in boosted cars and dont use X or H pipe installs then because they need a clean flow to maintain hp

[@joshuat2408]

I’ve had a Corvette C5 for 6 years. 180° headers 8 into one equal/unequal headers. all the major muffler companies. Doesn’t give me that exotic sound. I would love the car to have a hint more of. Definitely look into megaphones more might be what I’m looking for and keep me EPA compliant here in Cali :). thanks for the overview great video and insight

[@spaceT999]

i think the mega phone causes the flow to become linearized causing velocity to increase, and less disruption in the airflow. I bet if you added one of these after every bend you're going to have a pretty cool sound, and performance gain

[@FluidMotorUnion]

Video idea?!

[@hunkydory419]

Wow, that's an amazing tone\sound coming out of the back and you still hear enough of the turbo induction noise as well. Perfect balance of both. If there's no drone then that's actually the perfect exhaust!

[@Drunken_Hamster]

Wow, that's more than I thought it would do. Not really a direct comparison, however. I'd have liked to hear the actual car worked on with the existing system, then the fore, mid, and aft placements of the megaphones for a truly accurate back-to-back. In all my listening to exhaust, I've also noticed that the longer your merge, the smoother the blending of the sound is. Double X-pipes get more high-pitched than singles. Y-pipes with a long single section and stuff like the Mac Prochamber do the same. As for sizing a Y pipe to be unrestrictive, I believe I mentioned before that an exact match would be 1.414x the diameter as your duals, with the 4/3 rule (or 1.33x single diameter compared to duals) being "good enough" and potentially increasing velocity and scavenging in an N/A application. In this case, dual 3.5 into a single 5 since max flow is the priority to unburden the turbochargers. In any case, I wonder what a dual 3.5" into single 5" Y pipe, with or without a single big megaphone before splitting it back into 3.5" duals for the tail tips would've sounded like in this application. Another thing to consider for your pipe organ analogy; Have you thought of inserting a series of smaller pipes into a bigger pipe or chamber to get them to resonate at a different frequency or set of frequencies to compliment the base engine resonance peaks? Borla does this on some of their systems, and while I haven't necessarily _liked_ the few that I've heard, the idea is at least sound (pun intended) and I notice an audible difference between their basic systems and the ones they do this to when directly comparing them.

[@Levibetz]

Reminds me of brass instrument design obviously. One thing about brass, something like a french horn gets its characteristic smooth tone by having tubing that tapers over its entire length. Perhaps stepped diameter systems could replicate this? Ultimately we're talking about impedance matching. Look at how a compression driver is designed. A compression driver in free air isn't very loud, because it doesn't have much pressure to work against, where with a cone on it it can pull more current and really kick sound out. I suspect the megaphones are doing something similar, though I'm not sure how necking them back down effects this.

[@williamh6547]

Damn , that sounds really good, couldn't believe what a HUGE difference that made, and to be honest I wasn't expecting it. Great video, and thanks for the cheat sheet 😁

[@robbertmadden1386]

After watching one of OJs videos, I feel like I need to raise my hand to ask a question. Great job OJ !

[@aussiebevo103]

Man what a difference that mega phone made. Sounds absolutely mint

[@ozracin81]

That was very educational, feel like I should have took a test and got a cert at the end.. Thank you for taking the time to explain.

[@Carboneye7]

The test drive did not disappoint ! You have my sub Sir!

[@Firebird400]

Sounds a lot better after. Good job

[@applesbighatranch6906]

Regardless of any subjective choices and fluid dynamics theory, it would appear that you do top-shelf exhaust system fabrication. Very, very clean and tidy, sirs. Well done!

[@marshonmellows]

Try 6 into 1 equal length headers that sequentially fire, with steps, and a megaphone after the collector.

[@DanielBradley-b5m]

Great informative video, will definitely try this technique out in the future. Only thing I saw in question was the welding with no use of back purging. Id there a reason why?

[@garretabbott]

This guy is an excellent host! Really knows his stuff, great video

[@MaddMattsGarage]

Totally awesome, now I'm not a big budget dude but I appreciate the sound and I'm looking at my Jaguar XFR for both power and noise upgrades in the exhaust, the builds that FMU does makes for great inspiration. Cheers team.

[@FluidMotorUnion]

Hopefully it’s something you can try and get into your next system without being intimidated by those who say you need to be an engineer 😂. Try it see how it sounds, move it, try it again!

[@MaddMattsGarage]

Ha I have been fabricating an exhaust for my Ford Sierra xr4x4i (Ford Merkur in the US, as I live in New Zealand) and making changes to it and not being a competent welder and hence practicing on the Sierra, but since I'm into building my own I take inspiration from your works. But once I get the welding done then I'll progress into my more advanced cars.

[@Marfoir0303]

My profession is aircraft structural technician and I built hydraulic tubing and fuel lines at those diameters. I could see that those bends on that exhaust tubing wasn’t done by a professional because if you use a knuckle mandrel when making bends on a hydraulic production tube bender it will not crush your radius and not reduce flow

[@gideonyoun]

Love the thoughtfulness of the details you shared. Any chance you've built a system for an Audi b9 3.0 turbo? Would love to know if you did anything similar to this.

[@Endy5_Still_Alive]

I bet they could make my XB sound like a formula race engine with a single megaphone and some wood glue. FMU is amazing!

[@FluidMotorUnion]

Sounds like a possibility!

[@zkitzz123]

Dope, thank you sir. I will try this one day when I buy my first welder. You are awesome

[@FluidMotorUnion]

Good luck!

[@RichCadwalader]

Two cycle dirt bikes have this, it's called an echo chamber. Clean work, man! Looks good! Sounds Great!

[@JohnPolk2112]

I think it's called an "expansion" chamber!😂

[@Matua01]

I value your time in putting out the secrets of a well appreciated exotic tone.

[@roninthedestroyer8958]

I am in the middle of building a 68 AMC AMX 343 I have 1 5/8 headers to 3in collectors. I wanted 3 inch all to tailpipes. But the shop said he could not get 3 inches over the rear end especially being leaf springs. The engine is cammed rough idle and 11 : 1 compression. The 2.5 after the mufflers is going to choke the engine.

[@Carl_Jr]

The structure and presentation on this video surpasses a lot of your others, bar none. While certainly educational as are the others, this one seems less rehearsed and is truly OJ pulling knowledge from his back pocket of expertise. Great video!

[@LilYeshua]

Two stroke motorcycles have power valves to widen the power curve?

[@FluidMotorUnion]

Two strokes have much better results with a similar concept in "Zoomies" because of the frequency of the pulses, 4 strokes have less to gain than a two stroke and need to be more dialed in to get the effect but they work in the same manner.

[@TravisFabel]

This is a different subject but one I love. With a 2 stroke you dont have valves but rather ports. The height of the port determines at what RPM it is most efficient. A power valve takes an elongated port and covers/uncovers the port at specific RPMs to broaden the curve. This is completely seperate from exhaust tuning, that is critical in a two stroke for efficiency and therefore power. All fun stuff. Not related to this stuff, but super cool stuff.

[@wacabby]

can make even higher frequency, just stack two sets of megaphones. the principle works by creating a expansion of gasses, which slows the velocity, and then a partial collapse to speed up the gas. gas sped up, for a given pulsation, will increase in frequency, therefore appear to higher pitch.

[@maxenielsen]

A megaphone helps match the acoustic impedance of the tube to that of the open air. That results in more acoustic energy (pulses) leaving the tube. That’s why musical wind instruments have bells. So adding a megaphone on the final tube reduces scavenging. As you state, finding a gratifying sound while getting decent power boils down to a trial and error process. Unless, perhaps, one uses software to simultaneously model both aspects. Such software is definitely possible. Similar modeling software is in common and regular use in, say, electronic design. What software apps are out there for exhaust systems? Are you using it? Thanks! And, wow! That upgrade you did with the turbo equipped engine sounds absolutely awesome! Wow! I’m sure your customer loved it!

[@midwesterndrop-ape3066]

Just realized I’ve driven past your shop a bunch of times, great work on the exhaust.

[@FluidMotorUnion]

Much appreciated

[@a64738]

I replaced the rear muffler on my 1991 Mercedes 190E 2.0I with a big straight muffler with no restrictions and it sounded great and the fuel consumption dropped 5%.

[@davelowets]

The original "Ramchargers" drag racing group from back in the late 50s were a group of Chrysler engineers that were interested in drag racing. They had a very "sciencey" approach to modifying their "High and Mighty" 40s coupe. Those guys had a tuned megaphone hanging out of the bottom of the wheel opening on the front fenders for each cylinder of their Hemi engine. They also used long lengths of hose, similar to radiator hose, to run from each intake port out through a hole in the hood, and up to an intake plenum up on top of a "tower" on the hood. The carbs were WAY up there on top of the tower. The intake runners were very LONG. The intakes and megaphones were both tuned for 5000rpms, where the vehicle was shifted. The car looked strange for sure, but it worked well

[@bb4vic]

Great vid!... He pretty much said "if you let your Soul-Glo, the exhaust will flow!"

[@johnziska912]

Bitchin info... I worked in R&D at SuperTrapp/Kerker fabbing pipes for bikes for many years... Besides the dyno the flow bench was a good way to find what worked and what didnt muffler flow wise. Divider plates, pulse converters, stepped pipe crossovers....all in a days work. It was really fun working on systems for the H-D flat trackers or tuning on the dyno when they were in the area. Also, working with EPA, EEC, TUV and JMCA you really learn what it takes to extract some HP without exceeding their restrictions of Db. Fab On !!!

[@jonathanhill8268]

Sound difference was huge improvement, what were the power numbers?

[@patpowell862]

Dang. Ten minutes in and I felt like I signed up for an exhaust physics class. Moved on to different video.

[@mikejacobs4727]

I just rebuilt my Jaguar s type r . I have room 3/4 way down after were the resonator was . I already sent this to my buddy who is a professional welder . He gonna fabricate two for me and I'm gonna bolt them on . I can wait . The exhaust sounds decent now but I wasn't satisfied 100% this willale a huge difference I beleive

[@klikliks_service]

Wow, it's the first time I saw your channel. My goodness, you're a very detailed person. Great explanations too.

[@FluidMotorUnion]

Welcome aboard!

[@vigt548]

Demonstrating this on a car that we can all relate to was a great idea!

[@Thatdavemarsh]

Clearly a “track only” car. Not an emissions compliant device in sight? I’d be interested in how much the CAT dampens the pulses and reduces the effect. That is a beautiful exhaust with great work.

[@ronaldmasterbud1551]

OK, I Was Very Skeptical. But That Sounded Good, I'm Impressed !!!

[@IMR_Seb]

I know they probably aren’t considered “exotic” but do you guys ever work in Porsche exhaust? I’d assume they’d want to get the engine low like everyone else but you’re definitely gonna get constricted with not wanting the exhaust to clip/hit things vs minimizing tightness of the bends

[@FluidMotorUnion]

We do tons of Porsches check out our Porsche playlist

[@Brandonm50]

I now cannot stop thinking about adding megaphones to my exhaust system. But where to place them ?

[@pacman407]

Is there a megaphone length per displacement rule of thumb? Also, how do you feel about oval pipe compared to round (since oval allows for more ground clearance)? Would a megaphone work well with this style pipe?

[@FluidMotorUnion]

megaphones are really trial and error and oval pipes don't make too much of a difference and can be used when space is tight

[@pacman407]

Awesome. Thank you for the reply.

[@HeidiFegles]

The best exhaust is sized to the engine. And 0 restriction. Like dual 3.5” stainless mandrel bent with 0 muffler. And at the end kick it up to 5” at the end for the deep tone.

[@ronkirkham3410]

I just subscribed, I am 45 yr old.. have always had v8 cars/trucks and enjoyed Borla and other companies. Right now it's an audi s5 3.ot supercharged v6.. and the cat's are known as afail point and were I live I do not have to have them!... I would truly love to speak with you about this project and others..your help is greatly appreciated

[@FluidMotorUnion]

You can schedule consulting time with OJ! More information coming soon :)

[@ronkirkham3410]

@FluidMotorUnion that would be great is there a way I can leave a number or be able to be in touch with someone

[@DoubleBFPV]

Man yous guys really made that car sound freaking sick! Great work thanks for sharing!

[@FluidMotorUnion]

Glad you liked it!!

[@joecool7832]

Very comprehensive approach to performance and sound. Very well presented and to the point. Keep up the great work!

[@ImolaM5]

Good content! I actually designed my E39 M5s exhaust system after being inspired by FMU’s product for these cars. Now I want to add megaphones because I am looking for just a little more!

[@FluidMotorUnion]

Very cool!