Why Not to Put Exhaust Headers on Your Car

Why Not to Put Exhaust Headers on Your Car

rev up your engines, today I’m going to
talk about why not to put exhaust headers on your car’s engine,
now exhaust headers serve one purpose they allow the gas that has burned
inside your engine to come out the exhaust and then flow through the
catalytic converter through the muffler and out the back and on the factory cars
they’re called exhaust manifold, not header, cuz cast-iron can take a lot of
heat it’s strong it’s not gonna break, plus they’re relatively easy and cheap
to manufacture the exhaust manifold is under this heat shield it keeps the heat
from getting in and damaging anything under the hood and the design of the pipes
are for one main thing to get the exhaust gas to leave as fast as possible,
so the engine can have as most power as it possibly can and to run the most
efficiently, now when I was a young mechanic all vehicles were carburetored
practically and if you wanted more power out of a car, you could change the stock
to fancy headers like the ones in the picture behind me and a fancy headers
would flow better they had better heat characteristics,
they could be custom-made for each engine to get more horsepower, and since
they were simple, carburetored engines all you had to do was re-jet the carburetors,
put jets that were the right size so the air fuel mixture would remain perfect
since you changed how the exhaust flows you have to change how the air intake
comes in to put fuel into the engine, now back then if you had a stock Chevy 350
v8 engine and you put racing headers on them that were tuned correctly, you could
get maybe about 16 more horsepower out of that big v8 engine, but you have to
realize that most of that horsepower gain was at the really high rpms their
made more for racing than street driving since the headers aren’t made out of
cast iron, a lot of times they were stainless steel, cast iron is thick
stainless steel is thin, so they can have wider openings for the exhaust gas
the cast iron would be restricted down because it’s thick where the stainless
steel could be wide open and they’d flow better,
so headers in and of themselves don’t give your engine extra horsepower, they
just allow your engine to get the most horsepower out of its design that it
possibly can, while all modern cars are all fuel injected
and if you put headers on them you have to do a lot of reprogramming, you have to
find a mechanic with a five gas analyzer and a dynamometer and is able to
reprogram the computer to make it run correctly for the new flow that it has,
and in the case of many modern cars if you’re driving them on the Street in the United
States the exhaust manifold has the catalytic converter built-in, so if you
remove the stock and put on these racing headers you’re eliminating a catalytic
converter, you’re breaking the law you can’t take a Catalytic converter off a
car, so putting fancy headers on a modern car that you’re driving on the street
it’s just not a very smart idea now I know people are gonna say, Scotty oh the
guys that are modding their cars they put headers on, but yes that’s generally the
last thing they do when they totally modify a car to either race or to get a
ton of horsepower out of it and often in places where they don’t even do state
emissions testing, so they don’t have to worry about having it passed an emission
test every year to be on the road, first they’ll rebuilt the entire engine to
make it stronger, then they’ll put either a turbocharger or supercharger on it,
then on top of that as the finale they’ll stick nice fancy headers on the
engine so it flows as well as it possibly can and it has the most power
that it possibly can, now I still see guys trying to do it on street vehicles
here in Houston and then you see them going down the street and they’re shifting
gears you can hear the engine backfiring and popping through the exhaust, it’s
cause they just bolted headers on they didn’t change anything else and the car
doesn’t run right it can actually cause the Pistons to hole from pre-ignition
because they won’t run right, and sure they look cool when they’re under the
hood, a lot of times they’ll have them all polished and shiny and some of the
guys will wrap the headers with heat tape so they retain the heat better and
then they flow out faster for more power and they’ll remove the catalytic converter
sometimes even the muffler and have a totally free-flowing exhaust, they like
that giant loud sound, which is fine on a racetrack but in most places it’s highly
illegal they put out too much noise the decibel level is too high there’s laws
for that most states, so they won’t pass inspection because they’re too noisy and
since the stock exhaust manifolds have heat shields on them and the fancy ones
don’t, you stick headers on modern engine you can make the engine
compartment get way too hot, it’ll mess with the electronics and all the
wiring of a modern car and since you generally driving on the
street, these modern engine designs their stock are designed for generally
stop-and-go city traffic where they do most of their driving, not going top-end
a 130-140 miles an hour, so putting headers on any modern engine
it’s a dumb thing to do for something you’re driving every day on the street,
so now you know why it’s a dumb idea to put fancy headers on a modern car that
you’re gonna drive every day, sure it’s certainly fine if you’re building a race
car, for driving on the street that’s just stupid these days, because you’re
not gonna gain that much horsepower for the relatively large amount of money
you’re gonna spend putting the headers on and then having the system reprogram
to accept them correctly, so if you never want to miss another one of my new car
repair videos, remember to ring that Bell!

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About the Author: Maximilian Kuhn


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  2. Wow this guy no offence Scotty but you don't know what your talking about you seem to forget that newer cars have what's called an o2 sensor an this adjust you air to fuel mixture an does this live as your driving. So guys install those headers an enjoy

  3. I got headers on my car and I have not had one problem after installing headers increases you're low end torque and you don't even know what you're talking.

    Ps Scotty don't know jack crap

  4. I love my pops pops though 😂😂 Scotty you gotta stop making it seem like mods will ruin it lol my VQ35DE will be just fine 😉

  5. If it's your daily driver,true street car and just hanging headers on your 1-1/2 exhaust is plain stupid. Scotty is 100 percent right. To do it right you have to increase the diameter of your exhaust pipes. If I see a civic with headers and a 2 inch exhaust or smaller is hilarious. Then they stick a fart box, or god forbid dual fart cans, just a huge waste of money. Replacing exhaust manifolds with headers and doing nothing else to the car is just plain wrong

  6. i dont think scotty knows that everything is getting a turbo ….i mean the Chevy….. VW…..Honda….KIA…..Hyundai….ford…..dodge….and other companies under them (ex. Cadillac & Lincoln) mean other than Tesla what car company dose not have a turbo engine in a more than one model? "not a race car" im looking at a turbo sonic for a slow fun beater XD and damn right im going with a full exhaust kit not for power but that turbo sound with 35ish mpg….maybe not the way i drive but it will still get better mpg than anything i own. XD

  7. Scotty is going to tell you " Don't " in every thumbnail 😂😂😭
    And your going to hear the name "Toyota Celica " about every other video.

  8. Use to watch alot of his videos but the more I watch, the more I wonder about him. Hmmm I'm going to modify a car, exhaust, headers, etc. Scotty, buy a nice quiet Toyota and have no passion for your car.

  9. I disagree with this.. i put long tubes, true dual 3” pipes 2’ long with super 10s on the sides.. better power all across the board and better mpg without tuning..

  10. Scotty I have a 2015 Ram with a 5.7L that has a tick due to a known issue with exhaust manifold bolts shearing. The internet tells me that just replacing the bolts will only lead to the same problem. The internet recommends a quality shorty headers as a replacement and the issue does not reoccur What say you. Your advise is very welcome

  11. Scotty is partly correct in his assumptions, OK. Basically, what he is saying is for the benefit of a lot of young guys and girls who end up WASTING a lot of hard earned money in an attempt to gain more horse power , by having the usual 'mods' performed on there car. Often, due to poor research, they end up with poor quality or just the wrong type of headers, exhaust or software changes required to be of any benefit towards gaining an increase in real power output. Quite often the car actually goes disappointedly backwards and runs terribly. If your doing these 'mods' for show only, then fine. But if your doing them for REAL power gain, then be prepared for time in research, correct information, making sound industry contacts and most of all be prepared when it comes to a reasonable budget, in order to achieve the desired outcome.

  12. This guy can have fun with his stock grocery getters literally hates on everything people do besides keeping it stock .. not a true enthusiast

  13. Lol "You can't take your catalytic converter out of your car!" Thats funny, he must live in california. Cats. don't quite your car either, thats what the muffler does…Its literally in the name. Cats. just "clean" the exhaust and plug up the whole system.

  14. Used to enjoy watching this guy before he became ignorant about everything. He was wrong about so much. The length of the headers dictates were in the powercurve you gain. Guys ridiculous. headers are a great way to gain torque for cheap. And sounds better.

  15. Yes headers ARE better when done correctly, the problem is you have so many manufacturer make them too large to use on the street, and usually too short to get any real benefit from it (except high rpm). Most headers are horrible.

  16. Too much noise is illegal he said. Gun is small but make too much noise and kill people but legal. Why don’t you just install and gun to a car then so you drive a super loud noise thing that fully legal

  17. Cast manifolds are heavy RETAIN HEAT and crack more often than headers! Bad advice for the person wanting a smoother accelerating and running vehicle.

  18. What a joke i am assuming. He made this to humor all watching cause no mechanic is this Fricken Stuiped. Or ???????

  19. Is this video a joke? I've seen some of this guys other vids and he didnt seem stupid, he cant be this stupid, I feel like he is trolling everyone.

  20. Come on, Scotty. Stainless steel headers were a rarity back in carbureted times. Something that I saw less that one percent of the time, only on very high dollar show cars at the time, ones that usually did not even get driven. Don't worry, you are still awesome!!!

  21. My '85 Corvette with L98 V8 TPI engine has fabbed up sheet metal short tube style headers from the factory rather than cast exhaust manifolds. If I went on to put long tube style headers on my Corvette, the TPI system would automatically re calibrate the air/ fuel mixture for any added air flow and added power, as long as I make sure to hook up an O2 sensor in the new headers.

  22. Me: daily drives a modern car in the country, flies down dirt roads with high speeds
    Scotty: "your car is built for stop and go at low speeds"


  23. Buy the ceramic coated headers , they will keep the engine bay 50/70 percent cooler over stock cast iron , then rev up your engines ….

  24. I know several thousand people and not very many install tuned headers on their car, the ones that do are older chevelle's or hot rods, street rods, the young kids that put them on rice burners like to spend money, might as well let them, if 1000 watched this vid their might be 2 that don't do it. All motorcycles have these tuned headers on 'em, and most new cars have some sort of a tuned header from the factory, but a few still have a cast iron manifolds…

  25. Im doing this and welding a 3" straight pipe in my s70 98 that i got for next to nothing 😀 for rally reasons! (Still gonna take good care of it)

  26. If you remove that heat shield on ford, plastic valve cover dies. Everything dies. Everything melts like fukishima. But a ford made, standard non metric fukishima.

  27. So…old engines can have headers but not a modern engine..
    So them papdakis guys are messing up over there putting headers on toyota engines…tune it up

  28. I fitted el catless headers on my Toyota 86 and a crackle pop tune not only is the car way more responsive and smoother to drive but it has eliminated the torque gap and It gains HP on top end sorry Scotty I have to disagree with you on this one .

  29. Computer would not need to be reprogrammed, would not require any gas analyzing, nor would it require a dyno. The computer would pick up the flow rates and exhaust from the 02 sensors and work it out itself… We're not talking about putting headers on a 94 lumina here, you're doing much less work on an efi engine than you would be in a carb setup to see the same or better gains

  30. So let me get this straight, you basically want us other owners to keep our vehicles as stock as possible so it makes it easier to work on. What's the purpose of you bring a mechanic then?

  31. Headers on my 1965 Dodge Dart gives my baby slant six more power. They’ve been on for 7 years with NO leaks. I think it was worth it.

  32. Yeah, people always put header on AFTER they install their turbo, everyone knows stock catalytic converter a and headers mesh very well with 20+psi.

  33. Pre-ignition. Scotty, Have you ever heard of "Nock Sensors". Any car with EFI probably has them and the fact that the exhaust is allowed to pop, means the car is running without issues. It could also mean the person got the car tuned to cut rpm instead of fuel to limit engine speed. Also nobody is installing headers on a POS like that. Also you could have explained that Headers reduce low speed pulsing which is needed to help boost torque at low speeds. Most of the guys building engines know this and that's why on Nissan 240s, stock headers are often kept unless you begin running over 500Hp. It's also why some aftermarket companies use elements of the stock design to help improve flow and keep low end torque.

  34. What about shorty headers, high flow catalytic converters and catback exhausts…. Will they cause issues with the engine?

  35. Scotty only films on overcast days. This prevents him from getting distracted and yelling at clouds. Headers are the biggest bang for the buck power modification you can make. When installed with OEM O2 sensors, they require no "tuning" as he calls it.

  36. They take restrictions off basically, with no tune a tune is better but it’s absolutely fine ! I have a cat and I have full exhaust mate allways have and u don’t do up everything first then exhaust!!!’ Hahaha u have no idea at all

  37. Sounds loud which isn’t good for street driving.. gets more horse power.. Thanks Scotty! But I do think you should rename this video “Why you should put headers on your car”

  38. I put fancy headers on my modern car and couldnt be happier. Also im a car enthusiast and love to modify every bit of and, simply cause I know what im doing.. where i live, there are no emissions laws, sound restrictions or inspections for our cars. Scotty.. it just sounds like you dont know how to have a fun time in a modified car. Or! Plot twist! You were once a huge underground street racer and know the dangers of it and are trying to push people away from any car scenes.. either way. I pretty much dont agree with you on anything you say anymore 😔

  39. Ah… Scotty the PCM will automatically adjust the air/fuel mixture to adjust for the freer flowing exhaust. No special tuning required unless unless your optimizing timing.

  40. There's always that one old fart mechanic that is stuck in the early 80s during the gas crunch. I feel sorry for anybody who actually believes this crap.

  41. Watched more than 30+ scotty kilmer videos cuz i drive a Toyota corolla 199* wish YouTube recommended me this earlier now my car is always overheating because it's not taken care of

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