Benefits Of Individual Throttle Bodies


Hello, everyone and [welcome] in this video We’re going to be talking about how individual throttle bodies work, and so I’ve got two drawings here on the left We have a four-cylinder engine with a single throttle body and then on the right we have a four cylinder engine with individual Throttle bodies So looking here on the left, a very simple setup. Which you’re probably all very familiar with You have your air intake you know this is going to be a much longer winding path for most vehicles then you’ve got your throttle body that goes into your intake manifold and then into your engine Now with an individual throttle body as the name suggests each cylinder has its own Throttle and so you can have this intake manifold just like this setup And the you know air intake and all that you won’t have that throttle body right there before the intake manifold instead You’ll have one place at each of the intake Runners for each of the cylinders and in this case. I’ve drawn it So you’ve just got your cable for your throttle cable driven, or it could be an electronic motor there That’s going to be opening and closing this until all of those will open and close together Depending on you know where your foot is on the throttle pedal Now some of the differences between these One of the things that can be tricky which you may wonder is how do you tune the Air fuel [ratio] for a setup like this? Where you don’t have that you know massive Intake manifold with the vacuum which you can determine So what you’ll do is you’ll actually tap in vacuum lines into each of these intake Runners here and All of [that] will [feed] to a vacuum box, and then you can have a map sensor Which will connect up to that vacuum box if you’re unsure about how map sensors work I do have a separate video explaining that but that’s how you will tune In this example the Air fuel ratio of this system. Now, you know, what is the advantage of this system? Well It’s simple and it’s cost-effective And that’s why almost everyone uses this and you can size it accordingly for power. On the other hand here You’re going to have the biggest difference between these two is that in here you have a partial vacuum Leading up to that throttle body when you’re at partial Throttle versus in this system You have atmospheric pressure resting in your intake Manifold you don’t even need this you could honestly just remove that completely you know you have to worry about filtering in that scenario, but you don’t need this part of the system. The point is if you have atmosphere pressure directly outside each of these cylinders Versus in this case, that atmospheric pressure when you floor it has to travel all the way into the cylinder rather than [just] traveling from Right here to right here. So you know that’s one of the big advantages of this individual throttle body setup Is that you have Instantaneous throttle response because the second you press on that throttle that atmospheric pressure is right there and it goes right into your cylinder. So great to have that throttle response you’re also going to have reduced pumping losses at Partial Throttle because instead of drawing a vacuum through this giant area right here Instead you’re only going to be filling up this volume in each of these Intake Runners before you get to that throttle body, so you’re going to have a very small vacuum in comparison less pumping losses So this can be more efficient at partial Throttle. Now again as I mentioned you can remove This intake manifold here and in doing that you can improve the air flow for each of these cylinders So you can make it easier obviously. There’s no restriction coming in so that can be a horsepower benefit You don’t have those bends winding through that air intake if you do you know eliminate this whole system so from an efficiency standpoint It does make sense. Now which of these systems is going to make more power And that’s really not a question where you’re going to save this one or this one Really it comes down to sizing so you could have a very large intake manifold system on an engine that Isn’t restrictive at all and would allow for maximum horsepower at high RPM? And you could have a very restrictive You know small individual throttle body system, and so that at higher RPMs that wouldn’t work out so you can have you know Individually tuned velocity stacks for these where you make it very efficient for a certain RPM band But you don’t want to just say that you know inherently this is going to have more power than this Because that all comes down to the sizing of you know the piping in there And so you know one’s not necessarily better than the other from a power standpoint you are going to get Instantaneous throttle response you have the instant throttle response with this which will be great you’ll definitely notice that And then you’re going to have reduced pumping losses so more efficient at partial throttle. At wide open throttle You know it really depends on the setup one’s not necessarily going to be better than the other You just have to tune for what you’re going for high power high RPM means you’re going to want you know Shorter length intake Runners, you’re going to want larger intake Runners high power at lower RPM You’re going a lot longer runners, a bit more restrictive system, so it’s more turbulent, you get quicker airflow So thank you guys for watching and if you have any questions, or comments feel free to leave them below

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