Hey Veeky Forums

The increased load on the engine requires more air and fuel, which creates more energy and heat to spool the turbo.

If the engine isn't creating enough energy the turbo won't spool, which is why if you're just cruising along you won't be making eleventy billion psi of boost.

heat has energy.

hey for all we know you are fucking new too.
in fact you are fake so if you want us to believe your shit post bread on your hood you bitch otherwise you pick up all your costco coupons and piss off out of here very quick.

>hey for all we know you are fucking new too.
he might as well be when he tries to explain timing

So i changed my coolant and now my car is smoking, what did i do wrong?

She smokes a little but she's cherry.

>Turbos spool by airflow caused by both air consumption and expansion rate of this air
>Run at constant rpms under no load = draw in very little air = use very little fuel = low air volume in exhaust and low expansion of said air
HMM I FUCKING WONDER WHY IT WON'T SPOOL IF YOU'RE NOT SPOOLING IT

That's like asking why bicycle won't go faster if you don't pedal faster.

Probably spilled some on the headers.

hey what did i ask for you to do... post a pic of bread on hood ro go and annoy /ovg/ they love it.

oh damn ok im gonna head back over to facebook leave you's to chat about strange stuff....

bye.

uwotm8

Move this to the commie's thread, dont shit up this thread where a newfag is actually asking a wholesome question.

>go back to facebook
Holy fuck.

Post a pic of ur hand please.
I want to confirm my image of you I've built in my head. And your hands are a VERY important part of this image.

>Timing
Not important for the context
>RPM

How fast the engine goes.

The more you press the gas, the more air and fuel goes into engine, the more exhaust leaves the engine and goes into the turbo.

The more gas you give a car, the higher the RPM will be.

The higher the RPM will be, the engine works faster and more exhaust is let on faster

Ergo: More gas + More RPM = Turbo spool

ohhhh myy fuckinngg gooooooooooooddd

This isnt a fucking engineering class I dont want to hear about that fucking shit when youre suppossed to be psoting bmws in my fucking introduction thread and nooone is even paying it any mind

I have fucking HAd it with youuu

You would be an awful teacher.
You're giving him a bad impression of what RPM is and why/how it changes.
Someone who already understands this stuff can read that and understand what you're saying, but it's just very poorly thought out and structured for a n00b.

This person doesn't know how a turbo works and what RPM is. Of course im making it structured for someone that dont know shit about cars idiot.

But what if it's only when accelerating

The second half of my post, upon review, was also poorly structured.

I was trying to say that your post is NOT good for noobs.

Ok. Here's how it works.

RPM is how fast the crankshaft is going.

Revolutions per Minute.

the higher the RPM, the faster the insides of the engine move, the faster the flywheel goes, the faster everything moves, etc. That's the basics.

your gas pedal dictates how much air/fuel gets into the engine. The more air/fuel, the more power, and the more air/fuel burned, more exhaust is let on.

So the more you open the gas pedal, on ANY RPM, means you will get more power.

But the engine will always want to suck air and inject more fuel by itself if you dont stop pressing the gas pedal (when you press the gas pedal, you are only making the engine suck as much air as it wants to, then the computers inject as much fuel as there's air).

On top of what i''ve said, that the more you press the gas, the more power the engine will be making because there's more air/fuel, the engine will increase its RPM, because it can breath more easily, so it will increase RPM until the intake (the section that filters air, injects fuel, etc.) cant pass more air, and the engine cant rev any higher (slang for increase its RPM) Or until the computer kicks in and once it detects there's too much RPM it stops injecting fuel to avoid damaging the components (more RPM could damage components in the long run).
Now: Onto the turbos:

When you have more exhaust (you press teh gas pedal more) the exhaust per stroke (when the exhaust leaves the engine) will be more. When you increase the RPM, there will be a lot more strokes and a lot more exhaust coming out. That all makes the turbo spin faster.

OP I don't know either nut none of these answers seem very accurate.

Also these namefags need to get lynched.

Now, here's a thing:

Just because the more you press the gas pedal increases the rev doesn't mean that both are directly linked. You can increase the rev not having the gas pedal all the way, and you can lose RPM while having the gas pedal fully pressed (in case you are, say, turning or going uphill).

In cars with custom tuneable ignition timing (you can adjust the moment in which the computer sends electricity to the spark plugs) the screen will show a square showing a lot of squares defined by throttle position (how much you press gas) AND RPM, and then have many squares that define the timing depending on those two conditions.

You wont always find ways to do it every time, but you can replicate almost every throttle position in almost every RPM and vice versa. Just because an open throttle means a lot of RPM and closed throttle (idle, when you leave the gas be) means low RPM doesn't mean the car cant do something else.

This is the most uneducated nonsense I've seen on this board today.

youre embarrassing yourself.

Blow on a little case fan.
The harder you blow the faster the fan spins.

That's literally it.

someone plz halp, i plan to flush my coolant tommorow, don't wanna waste money

Your arguments truly leave me on the ground. I thought that my years of engineering study and wrenching and working as a mechanic made me learn everything about how a car and engine works and why but now i realize that with those posts i actually know nothing.

Dear OP

It's all about heat and pressure. Hot air takes up a lot more space vs cold air. When you're not on the throttle, you have less "bangs" per second. This means the exhaust isn't all that hot.
When you get on the gas, a lot of "bangs" happen and that means a lot of heat. That heat makes the exhaust try and expand, problem is, it can't, because the exhaust between the engine and the turbocharger only has a limited volume.
So if the volume can't increase, then the pressure of the exhaust gas increase. The exhaust that goes after the turbo goes to the outside air which is at a low pressure. So all your high pressure exhaust gets shoved through an even smaller hole (increasing pressure even more) and then it hits the blades of the turbine on it's way out of the turbo so it can go out the exhaust and get to the area of low pressure. This makes the turbine spin really fucking fast which obviously spins your compressor wheel and produces pressure in the intake.

This is why wrapping or ceramic coating your headers and using a turbo blanket can cause the turbo charger to spool earlier, because you're keeping heat inside the exhaust instead of letting that air cool down, which lowers the pressure inside the exhaust.

Also, if you have an electronic boost controller, it may bleed off pressure and not allow the intake air to become pressurized until it sees a certain amount of throttle input. This is beneficial to gas mileage.

33 replies and not one mentioning a waste gate.

The fuck is wrong with you all?

because wastegate is not an essential component for the explanation of a turbo. Neither is the BOV nor the oil lines nor the coolant lines.

The wastegate isn't going to open until you at least hit the fucking wastegate spring pressure. So it's completely irrelevant until you're making boost.

...

>This is why wrapping or ceramic coating your headers and using a turbo blanket can cause the turbo charger to spool earlier, because you're keeping heat inside the exhaust instead of letting that air cool down, which lowers the pressure inside the exhaust.
naw, thats done to keep engine bay temps down.

It does both my friend.
Most non-engineers discount the thermals of turbo systems.
Thermals are fucking huge in turbo cars.

Real OP here,
first of all thanks to everyone that replied but I got mixed info on all that.
Also, did not expect the whole thread to be shitposted so much, you ant Veeky Forums seems a fun lot indeed.

So let me sum it up:

Let's say I drive my car (pic related) in 4th gear, at 2000 RPM on a flat surface. With my turbo gauge I see, let's say, almost nil boost manifold pressure, OK, that's because the engine, while doing some RPM already, it's just sipping air and fuel due to the low power required to keep the car rolling at that speed.

Then I want to bring the car at 3000 RPM, same gear, same flat surface. I accelerate so the turbo build a boost spike until reaches that 3K rpm, and then boost goes down again as the car settle to that speed using again little fuel and air.

If I hit a flat motorway and bring the car to that starting 2000 RPM but on 6th gear, then I'd be doing motorway speeds; and the car this time has some steady turbo boost pressure because at those speed there are far more air/tyres resistance and so the engine has to produce some power to keep that speed.

So my conclusion is: turbo are spooled by the exhaust pressure, made by the burnt air/fuel mixture that the ECU delivers into the cylinders. Since the car can go under load at almost any RPM, while that factor matters, is actually the produced power (so more air/fuel burnt) to overcome the load that make the turbo going.

Is that somewhat ok?

...

>gas engine
There is a butterfy valve between the compressor and the intake manifold, it controlls the airflow into your engine.
You controll it with your accellerator pedal.
The more rpm and the more you open it, the more exaust gas drives the turbine, wich drives the compressor, wich builds boost.
>diesel engine
The power here is regulated by the amount of fuel you inject into the engine, there is no butterfly valve.
The more fuel you inject, the more exaust gas volume you create, the more you drive the turbine the more you build boost.

YES! YOU GOT IT PERFECTLY! (except the ECU part, there are carbed turbos).

The more horsepower a car has (regardless if the car just has a bigger displacement or higher RPM limit) the bigger turbo you can have, because if you stick a turbo too big the engine may not produce enough power to spool it up.

Wow I think this may actually be a correct and concise answer.