No More Exhaust Myths - /ENGINEERED 

Number 1 and 3 tubes will need to be beaten nearly closed to clear steering box.

Exactly.!! the engineers that design vehicles have absolutely know idea what it takes to fix / work on them.. Cars should be designed by Real mechanics. which would help make repairs easier / cheaper.. the newer the vehicle is, the more over engineered it is.. which makes costs go up with repairs.. way more people need to know about this.

Don't forget close enough to the plug wires to burn them out frequently

Don't forget to wrap the headers around the starter

Yessss! I'm a tire and oil tech and I hate this, it mostly seems to be GMC that jus loves putting the oil filter next to or behind the fucking manifold!

That's p-unny

Booooo

+AJHedges I thought it flowed pretty well actually

+AJHedges i'm sorry but for me those 30min passed like 5 minutes if you are really interesed

It was a joke...

I think the warranty is usually voided after you start blowing...

Phil Jones

HAHAHAHAHAHAHA

😂

@pete smyth you do realize this is not really any engineering conference but a random video on the net, don't you?

ikr lol

+markiplierSINGSb.a.d.l.y. A bare bones, Formal intro. I wish they would do a sexual innuendo intro to spice up the beginning. Missed opportunity.

+markiplierSINGSb.a.d.l.y. Coloquial terms for the 4 stroke cycle: intake, compression, power, exhaust.

+markiplierSINGSb.a.d.l.y. Actually a very witty and intelligent intro ;)

+markiplierSINGSb.a.d.l.y. a good one. why, what was wrong with it?

TargaWheels haaha😂 si si yes

I kept thinking of my old one I sold in the late 80s. I loved that car.

I had a difficult time taking my eyes off of it.

Yah that’s mine. 😝

Bro! SAME!

+JD Perham Magnaflow doesnt make turbo manifold

iStanceDaily Hub right, that doesn't meant they can't talk about the science behind it

+JD Perham If they don't make turbo manifolds, he'd be talking about an area in which they really don't have a right to talk about, so he could spread mis-information and degrade the reputation of the company. A wise choice by him not to talk about it, but it is a shame turbo's were left out of the video.

This is true and a good point, but they do make cat backs for turbo based cars so hopefully they do have some engineering experience with them, which would have been nice to be shared here. Oh well maybe another video from another company some time then

+Rich Smit Except that locomotive engines are 2 stroke, and diesel... that completely blows (no pun intended) this discussion out of the water. The EMD/GM 2 stroke needs that blower to force the exhaust gas out of the cylinder, without it, it won't run. The 567/645/710 engines have ports like a chainsaw or weedeater motor on the low end of the cylinder bore. When the piston is far enough down, it uncovers those ports and fresh air from the blower or hybrid turbo charger forces the air into the cylinder, also at the same time the 4 exhaust valves open up and let the combusted fuel air mix out, while the fresh air from the blower fills in from the bottom. Once the piston moves up and closes the port off, the power cycle starts again, and fuel is injected when the appropriate timing dictates. I said hybrid turbo because the turbos on the EMD locomotives are actually gear driven at low speeds, and once the engine output is high enough, the exhaust turbine will pick up the compressor load, and the overrunning clutch allows the turbo to spin faster than the gear drive could spin it. That's why most of the 645/710 engines have that yang yang yang yang sound at an idle... that's the turbo gear drive you're hearing.

You aint even married yet and already putting up with this BS?

lilpoindexter ikr the horror of this generation lol

Rusty Ranger bruh I can't get mine off of me.

+ Speed of darkness. Some of us are more fortunate than others lol

Speed of Darkness bro super glue is not a good lubricant!!!!

Elhadji Amadou Johnson u must have magnaflow exhaust😂

Decat all the way😄

JonnyD3ath not possible due to emissions

+omfgwtfbbq90 "not possible" 😏😜

+omfgwtfbbq90 If you can dream it, you can do it.

+omfgwtfbbq90 pff, cuz he knows we don't run that shit on our cars...

everything you need to know about the back pressure myth is there you just have to not be an idiot and think a little bit, he explained all about tube diameter and exhaust velocity, airflow, and exhaust pulses helping extraction. He just didn't outright say it maybe to help weed out the retards who can fuck off.

by what i got was. If the tube is too big at the header its bad but mainly if the tube size isnt consistent all the way down the system. its worse

He mentioned the science about back pressure when he spoke about the restriction in the header causing an increase in peak torque vs average torque. That's where the back pressure comes in. Now, if you want overall torque, open that exhaust up and let it flow.

Back pressure isnt that important but you need about a minimum of 1ft of pipe and good tuning to not warp valves. Dealing with race cars bassically all I've noticed. Friend ran open header on his 302 f15p for 4 years towing and daily use and never had an issue but was very well tuned and he had a 3in to 2in on the collector to retain alittle back pressure. Loud as hell though but loved it

Cfm to tube size.

Turbo Exhaust is for a whole nother program/video. The most important takeaway from this video is that a Flowmaster chambered muffler will not flow as much air as a straight pipe --- but a perforated glasspack can and WILL flow as much (or more) air than a straight piece of pipe.

Do you? Pressure and velocity will both drop at some point.

+DrewLSsix Educate yourself. www.princeton.edu/~asmits/Bicycle_web/Bernoulli.html

+eric kemp The Bernoulli equation applies at constant mass flow. An engine varying its angular velocity does not have constant mass flow, so both pressure and velocity can drop simultaneously.

+Paul Optional Siegfried That's a good point, but not entirely relevant to the situation in question. Richard states, "...as long as the drop in pressure does not impede upon the CFM airflow..." What I'm saying is that a drop in pressure would increase airflow. What he meant to say was, "...as long as the drop in VELOCITY does not impede upon the CFM airflow..."

+eric kemp I think what he is trying to get at is that in a full system a drop in one of the two would result in an increased resistance to flow through the system hence dropping the other. I may be wrong as Im only just getting an understanding of this side of things but that was how I understood it

I know very well, don't take it so seriously it is just the internet. I am a engineering student myself actually. So I know the information here is kinda superficial....

+Mari Onette sssssshhhhhh, dont tell them that.. Before he thought the exhaust was just to keep it quite. now he tells his mates his exhaust is fully modified super customized electronic pressurized badass

YES!! That's what I wanted to hear the MOST!

David Stuck don’t use

They're pretty efficient these days. I mean sports cars come with them and they're making more power than ever out of smaller displacement engines.

Exactly! Picture of the video showed catyletic converters and didnt even talk about them...dumb. maybe they had to remove that part so they dont get sued??

Cats don’t give up shit. It’s like 2% on 1000hp engine. On stuff less than that, its negligible

Just briefly he said if the diameter was too large it creates a restriction.

at the header

proto35 it was discussed the whole time hahaha

proto35 people think of restrictions when in fact it is velocity you want.

Maybe they think back pressure adds torque because it reduces losses from cam overlap. Course the same back pressure cancels out the top end power the over lap was put in to achieve in the first place.

Agreed!

Jarrod Swick you saved me 30 minutes

Apparently straight pipe has less flow than a MagnaFlow muffler because of friction lol

nope. 21:02

Actually it's still true, only dictated by length. If the pipe was long, this would be an issue. The length of the pipe needs to be more or less tuned to the CFM flow volume and speed. Temperature drop is a factor to.

F.G. Kaye Don’t use cat.

Cut them off. Sell it

Leibel 500 to 600 m/s depends the temperature

It all depends on the temperature, the speed of sound is slower than exhaust gas in Siberian gulag, comrade. 306 m/s at -40C, 411m/s at 300F lol

+1 !!!

that was the first thing I noticed too

+SexyMistaMustard Guy makes some money, eh? Also bonus points to us for noticing. :p

I love that watch maker, I always notice when someone has one on.

Doesn't match his t shirt though....but you can tell he put that shirt on for the interview

ChrisHallett83 or u u can turn the headers upwards and have them come out through the hood and make some holes on it😀

They're getting much better, and smaller (not internal diameter).

That depends on the type of Catalytic converter. Early General Motors and Toyota cats were the pan-type, which had the active ingredients in a semi-pellet form, and they were very restrictive, compared to the modern "Honeycomb" design, which will flow enough air to accomodate about 350 HP PER BANK without loss of exhaust flow . Today, we have 700 HP cars with full cats in place -- on the street, and LEGAL in ALL 50 states. Novices and morons get in line to eliminate their cats -- while they scorn the folks that want to keep our air and water clean. I've run a lot of illegal shit over the years, but nothing that could compromise our air quality.

Chuck Hallowell because racecar

@@BrandonKent136 WTF is wrong with you!?? Did you miss your nap !??

Brad Nay don’t use

+Foxontherun2 You didn't watch the video, did you.

puts a dip in and cracks beer...

Yeah I did,so.

Jesus

Never had a v-8 ;o)

brwi1 buy a drum kit and practice practice practice

Try watching it on Lucy. I feel like i just went to college.

Alexander Garcia hahha baked 😂 square ass 😂 hahah

..and yet we persisted...

+James Tennier That is correct. A four stroke engine takes 720 degrees of rotation per fire in a cylinder. Power stroke, then exhaust stroke.

720’ / 8 cylinders = 90 / cylBut the banks are tilted, so the bank angle comes into play too. A V8 will usually be 90’ between banks, with pistons sharing 4 crank bearing points, so you have two 4-cyl banks with one lagging the other by 90 degrees. Now you can spac the four cranks by 90 degrees, pick your 180 degree pairings, assign a firing order, design your cams, and finally run your header tubes for optimal pairings.

Bit lateresponding, but close - exhaust pulses 180 degrees apart are grouped together - the other four are 90 degrees to the first. In practice, that usually means the outer two on one band and the inner two on the other, eg traditional SBC has a firing order of 18436572 with the left (?) bank being odd and the right even so one group will be 1, 7, 4 and 6 and the other group would be 3, 5, 2 and 8. You can check that and other engines on the interweb, as there are multiple sources.

Well I don't believe scavenging works on the street as header manufacturers would lead you to believe. The reasons are complex but it's something like this, cross plane cranks benefit from scavenging but it occurs in such a narrow band as to be pointless chasing it on a motor that has such a broad spread of power as a street engine. There are too many variables for it to work properly. There is a way however that MAY (no promises) work and that is anti reversion cones in each of the primary tubes. There are some things that are known to work generally for specific motors. For example the 440 Mopar is known to benefit from 2" primary tube headers going into 3 1/2' collectors. Indeed it seems to be the case but that is from a factory sponsored drag racing data collection and the info gained is so narrow nothing is relevant outside that particular motor with iron heads and larger valves as specified by the factory manual for hot rodding the B/RB. I am sure there are other knowns for other motors, but for the home hot rodder unless you have a dyno, about 1000 hrs, $150k, 49 different combos of header primary tube length, intake type, head work valve size, port size, camshaft and on and on and on into infinity then you're just guessing. Headers are about reducing pumping losses and stopping reversion. Some do it better than others, but the main cylinder filling effect is the inertia of gas flow initiated by camshaft lead and lag (AKA overlap). How well that flow can be kept moving, post exhaust, may give an added boost but I doubt all cylinders are going to benefit equally due to intake manifolding! The whole header thing is designed to even it all out as much as possible by having the leaner cylinders running at the correct A/F ratio and the richer ones running too rich rather than the richer cylinders running the correct A/F ration and the leaner ones being a bit too lean but within specs for longevity. The whole thing is a balancing act and reducing exhaust pumping losses will yield a power increase since the the volumetric efficience of the engine has changed. Port fuel injection aids this since the intake runners are intentionally tuned. So that's my take on it. Header manufacturers say it's science, I disagree, so I guess they're right and I'm wrong because they have more money than me implying I have shit for brains. As I mentioned they're right.

A THIRTY MINUTE ad! A little more like an infomercial.

I wish more ads were like this. If there was ever a real case to convince someone of the value of your product it's using an experienced engineer like this to share information with a crowd of actually interested buyers.

That's not just another way to look at it but a bad way to look at it.

Do you?

I wonder if he's a dad?

Agreed

your an idiot

corvette z06 guy probably doesnt evem have a corvetter

+Stephen Cain Learn the difference between "your" and "you're" before calling someone an idiot.

corvettez06ss yeah exactly

+Woo Cheol Shin My Roush muffler (actually made by Borla) on my mustang has no highway drone and is loud as hell when you get on it and it's a straight through absorption design.

+Woo Cheol Shin The exact opposite is true. If you have an absorption muffler that drones, then the absorption material has failed. An easy way to tell is to tap the outside of the muffler, if you here a dead thud, then the absorption material is OK. If the outside surface rings when you hit it, then the material has failed. For comparison, I had 70 series Flowmaster on my motorhome. Not only did they kill the mileage and power, but they droned like crazy because even through the sound bounced around in the chamber, the noise transferred through the case, because there is nothing to absorb it. The 70 series may have been quiet at the end of the pipe, but up by the muffler, it was very noisy. I removed the pair of 70 series Chokemasters, and installed two Magnaflow mufflers. I made no other changes to the system. The mufflers were much quieter in the coach, with no drone. My mileage went from 6 mpg to 8.5 mpg. My zero to 60 time went from 19 seconds to 16.5 seconds.

The Dynomax ultraflow sounds good and doesn't drone any more than a Flowmaster 40. I don't care for the Magnaflow sound though. It's too bland and quiet.

Woo Cheol Shin this was not about sound...lol

Not really garbage. Just over priced.

Not really garbage. Just over priced.

When battery technology gets better and energy recovery increases range electric vehicles will be more prevalent. In fact, all aspects of electric vehicles need to be improved.(cost, range, lifespan) At present, 25%~30% efficient IC engines 'rool'