Koenigsegg Proves You Don't Need A Straight Pipe Exhaust

hello everyone and welcome in this video we're gonna be talking about two different Koenigsegg exhaust patents that allow them to run crazy high horsepower engines over a thousand horsepower and yet still remain emissions compliant now a big thank you to simply safe for sponsoring this video we'll get more into that at the end of the video but know that there is a link to check out in the video description now in order to understand these Koenigsegg patents there's a bit of a logic train that we need to take so we're gonna start at the very beginning and then work our way through so the whole idea of an exhaust system that exhaust pipe from your engine is that you need to get those spent exhaust gases from your engine and out and away from the car so that you can bring in new air new fuel and continue to make good power well the problem is this exhaust has some bad gases in it some harmful emissions that aren't good for our health but humans are very clever we're not going to let that stop us we want to have some fun with some cars so we designed this thing called a catalytic converter and it helps get rid of those bad gases many of those bad gases that are going out that exhaust okay well the problem with this catalytic converter now is that it creates a restriction so ideally you would just have a straight pipe exhaust where your exhaust comes out and then it just travels through the ideally designed exhaust pipe diameter and out the back this gives you the minimum restriction and allows you to make the most power unfortunately that is not emissions legal so it's not going to help out with those bad gases that the exhaust is creating and if you're a manufacturer that's trying to sell cars to the public that's not going to work so you have to come up with something in order to prevent it so manufacturers use catalytic converters within the exhaust well they use a pre cat and a main cat there's two different catalytic converters here in this system that I've drawn and the reason being is that this main cat isn't effective until it's at operating temperature so let's say you just started your car everything's cold the exhaust is cold so all those harmful emissions are just passing right through that catalytic converter they're not being converted and they're just going out into the atmosphere so we're trying to prevent the bad emissions before this thing has gotten warm and so what manufacturers do is they put a pre catalytic converter that's closer to the exhaust manifold it's got that dense core that the exhaust gases have to through and as a result it gets out some of those harmful emissions on startup so it's not the best thing in the world that doesn't solve all the problems and until this is that operating temperature it's basically just as good as we can get so it's going to help reduce emissions at startup for that short duration where your engine is cold once the engine is warm this main catalytic converter is really going to do the work and it's very effective at converting those harmful emissions those nitrogen oxides and so this can be sized whatever size you want if you need a thousand horsepower engine no problem you make the catalytic converter bigger you can make do with a catalytic converter or whatever power you want that's used in rally car it's used in supercars it's used in these thousand horsepower connects legs so it's you're able to do it the problem is this pre catalytic converter right here this is what's going to create a restriction even once we're at operating temperature now all we need is this main catalytic converter but we still have this small dense pre catalytic converter acting as a restriction on our system and causing us to lose horsepower that's obviously not good so we need to do something about that now before we can get into the solution Koenigsegg wants to make big power and to do so they're using turbochargers so we need to add a turbocharger to the mix here and that gives us really two options that you'll see most manufacturers using as far as where do they place that pre catalytic converter they can place it before the turbocharger or after the turbocharger now if they place it before that's ideal for the pre catalytic converter because it means it's getting those hot exhaust gases immediately out of your exhaust manifold but then it's creating that restriction before your turbo and it's also taking some of the energy before it reaches the turbo so it's going to take a little bit longer to spool up that turbocharger it's not going to react as quickly so it's not really ideal to use this method so you place the pre catalytic converter after the turbocharger that way your turbocharger gets those exhaust gases immediately and you get good response from the engine unfortunately this turbocharger takes away some of that heat because it's converting that energy from the exhaust into useful work to create boost for this engine and so because it's dropping the temperature of the exhaust that means it's going to take even longer and heat everything up and even longer to heat up your pre catalytic converter so your pre catalytic come is going to receive cooler exhaust and it's not going to be as effective at eliminating those emissions now either way you have to choose one of these if you're going to make this great emissions compliant engine with the turbocharger and either way you're going to have the restrictive pre catalytic converter which means you're basically going to reduce your maximum capability of a boost and another thing that this does that may not be quite as simple to see just looking at this is this pre catalytic converter is going to cause back pressure within this exhaust which is going to build up the pressure between the turbo and the exhaust and in doing so it's going to force some of that air that's trying to come out of the engine to remain in that engine and because that hot exhaust remains in the engine it's going to increase the cylinder temperatures you're going to have hot EGR which isn't good so you can't use those gases for combustion and they're heating up that cylinder so you're gonna have more likelihood for running into engine knock as a result you get less boost and as a result you have to pull timing and you make way less power so the sad thing about putting the pre catalytic converter in either of these locations is you're ultimately going to lose power so how does Koenigsegg get around this so Koenigseggs very first patent which I believe was in 2004 was the rocket cat which was used in the Koenigsegg CCR now we're looking at here a zoomed in version of this pre cat and this main catalytic converter and so what's going on is you have your flow it comes in and it passes through this pre catalytic converter which is held within this chamber that has a path around the pre catalytic converter that the exhaust could also flow now at low flow your flow is always going to take the path of least resistance so at low flow is just gonna simply go in here this isn't all that restrictive because you don't have all that much exhaust flowing in and it's how this design forces the air to flow so it comes in this pre catalytic converter travels out and then travels through the main catalytic converter so you get the benefits of that pre catalytic converter at low flow and that when you're in very high flow when you step on the gas and you want to make full horsepower well there are other alternatives for the exhaust to go through this so instead of being forced to all only go through that pre-cut some of that exhaust gas will also go out and around the pre-cut and then to the main catalytic converter so you open up the amount of space that has the exhaust has to flow around this pre catalytic converter and in doing so you reduce the restriction it just takes that path of least resistance and you're able to make more power now the beautiful thing about this system and their first patent is that there's absolutely no moving parts to it it's extremely simple it's always gonna work it just passes through it's a static system that you don't have to worry about things kind of falling apart or moving parts rubbing against each other and wearing out you just have that flow go through it and then off you go and koenigsegg says they're able to get over a hundred horsepower increase by using this system versus using a system like this that is very restrictive now it's not this system that's creating horsepower it's the fact that you're reducing a restriction so this is taking away horsepower this is allowing you to keep the horsepower that you are making so finally we get to a 2011 patent of Koenigsegg 'he's used on the Agera RS and so this engine is producing 1160 horsepower crazy high power levels obviously you need an exhaust that is not that restrictive and so the very clever thing they did with this exhaust system is they incorporated bypass valves and so your exhaust comes out and when you first start your car and you know you're not making all that much power your engine's cold so you don't want to run it hard yet while you're first starting up that car then the exhaust is going to be closed off from the turbocharger and instead forced to route a different direction through the pre catalytic converter bypassing the turbocharger and then through the main catalytic converter now you might be wondering we'll wait a minute what if I want power from the get-go well first of all you shouldn't be driving your car really hard until the engines warmed up so I think the system is very clever in that it's only going to be really used when you are your engine is cold and you shouldn't be driving hard anyways second I'm sure if you were to floor it because for some reason you just had to have 1,100 horsepower in that moment they'll close this off and they'll allow that exhaust gas to be routed through the turbochargers so there's a logic built into it to incorporate the scenario that you're driving in so once the engine is warm and you no longer need to heat up this main catalytic converter to get it functioning you close off this pre catalytic murder and all of your exhaust then passes through your turbocharger and then through the main Keller converter which is sized appropriately for this engine so you no longer have to worry about that initial problem we discussed of having a pre catalytic converter that is always creating restriction on your entire exhaust system here it's only there at the very beginning when your engine is cold and then once things are warmed up you bypass it completely the main catalytic converter does its job and helps convert those harmful emissions and you size it appropriately for the system so you can make those crazy high horsepower numbers now Koenigsegg claims this frees up over 300 horsepower for this engine which is absolutely nuts and another very cool thing about this exhaust is that they claim at least when this came out that they were the only high powered turbocharged engine where the exhaust pressure was actually lower than the intake pressure as a result of incorporating this system so they said that for example if you were to have 1.5 bar of pressure in your intake manifold they would have about 1.3 more of pressure less than the intake manifold in the exhaust manifold versus traditionally if you were to do this you know using a system like this you'd have something like 1.5 bar in the intake manifold and then 2.5 bar in the exhaust manifold and of course the problem with that having a higher pressure on this side versus this side means that you're going to force some of that exhaust gas to remain in the cylinder it heats up the cylinder it means you've got less air and fuel to work with it means you've got less boost to work with the hot cylinder means you have to pull timing so you don't run into knock and all of this means you start to lose power so that's why this system can free up over 300 horsepower because there are cascading effects of having this pre catalytic converter in line with the turbocharger and always creating that restriction so it's very cool what Koenigsegg came up with how to create this street-legal 1100 some horsepower engine now again a big thank you to simply say for sponsoring in this video I actually bought a simply safe system several months ago after talking with some friends who had recommended it while moving into my new home the system is super easy to use and install I probably spent about 30 minutes getting the entire system operating how the ability to check on my phone at any time that my house isn't on fire that the front door and the garage door are both closed that there's no water leaking in my basement then the temperature isn't near freezing in my house so I don't have to worry about pipes bursting it all helps with peace of mind everything is professionally monitored 24/7 it even works in the case of a power outage and there's no contract to get locked into with fair monthly pricing I also love the doorbell camera which allows me to see when packages arrive and also records any motion so if someone were to try and steal my packages I would get a video of that there are all kinds of different sensors as I've already touched on and others including glass breaking sensors or motion sensors that are pet-friendly and allow you to adjust the sensitivity you can check out simply safe using the link in my video description if you have any questions or comments of course feel free to leave those below thanks for watching

Channel: Engineering Explained

Views: 348,654

Rating: 4.9289942 out of 5

Keywords: straight piped exhaust, straight pipe, exhaust, performance exhaust, car exhaust, catback, aftermarket exhaust, koenigsegg exhaust, borla, magnaflow, exhaust pipe, catalytic converter, high flow catalytic converter, exhaust patent, koenigsegg patent, rocket cat, engineering, science, horsepower, torque, engineering explained

Id: MlAwPszq2iw

Length: 12min 1sec (721 seconds)

Published: Wed Aug 21 2019

Reddit Comments

[u/KaiSimple]

The only thing is that, he does all of this on a marker board. So that being said, although his calculation is correct, without putting it to actual test it just theory.

[u/Reaper_Messiah]

This was an extremely interesting video, thanks for sharing