When i speed up and turn off the ignition, the combustion sound doesnt.
And when pushing the throttle the combustion sound gets louder -
even though the revs come down.
(i drove the FZR)

I expected to hear just tire rolling sounds.

Any ideas?

The engine is still turning and acting as a pump, so it will still make some noises. The volume of air going through the pump is controlled by the throttle, and will control the aural volume. So it's not far out.

At least, that's my understanding of the situation, although recently I seem to be getter 'wronger and wronger'...

Quote from tristancliffe :

At least, that's my understanding of the situation, although recently I seem to be getter 'wronger and wronger'...

It's because of this.

Quote from tristancliffe :

The engine is still turning and acting as a pump, so it will still make some noises. The volume of air going through the pump is controlled by the throttle, and will control the aural volume.

No, throttle either controles the amount of fuel vaporized in the carborator or the amount of fuel being injected. There are some sort of air mass regulators, but they dont cause noises like that. Sorry to say that.


And combustion does not take place, so there shouldnt be any kind of hard noise.

:detective

I'm sorry, the big community always knows everything better than the devs.
Please take my opinion just as suggestion.

:eclipsee_

The throttle (on a gasoline engine) controls a valve, usually a butterfly value or a slide valve, and controls ONLY the volume flow rate of air. In a carb it is the pressure drop across the venturi (which is affected by throttle position) that mainly controls the fuelling (on a simplified carb, obviously it's rather more complex than that), and an an injected engine it is either an electronic or mechanical system that decides how much fuel to inject based on throttle, load, rpms etc etc etc.

To say the throttle controls the fuel directly (as I understood you to have implied) is wrong.

Of course, wthout combustion there shouldn't be combustion sounds, but that is the limit of the LFS engine. But a real life engine will develop noises due to work on the air itself, and the volume/tone of that noise will be controlled by the throttle valve.

Take an engine. Remove fuel system. Spin engine (either via transmission and road friction or by alternative means) up to a decent speed, and it will make airy noises. Hell, get a tube with a piston in it, and move the piston - the tube will make a noise.

I never said LFS was perfect, just that it wasn't far wrong.

i know this is O/T, but i gotta ask this question in here; if the gas pedal does what you say tristan, does that mean that if you floor the gas pedal in a lower gear, does that mean you get better gas mileage than barely on the pdeal at a slightly higher (1k to 2k+) RPM?

Quote from XCNuse :

i know this is O/T, but i gotta ask this question in here; if the gas pedal does what you say tristan, does that mean that if you floor the gas pedal in a lower gear, does that mean you get better gas mileage than barely on the pdeal at a slightly higher (1k to 2k+) RPM?

That's why we have transmissions (and because of the small powerband of engines). I just read on how a carburator works. When you press the accelerator, more air is let in. When the pistons stroke down, the air is sucked in, which sucks a needle in the carb that lets more fuel in.

@XCNuse: I would think that at maximum output, the engine probably loses a great deal of efficiency. But that's purely a guess on my part. Also, at low RPM's, you're not generating as much vacuum pressure as you would at high RPM. I've actually experienced this on my bike. I'm in top gear at about half throttle. I twist the throttle a little more, I get a slight boost in acceleration. I twist it all the way to full throttle, and I get no noticable boost in acceleration. Granted, that may be due to it being carbureted.

I remember pulling a car with a dead battery to start it.
And it made pumping sounds due to compression etc.
So yes, you're right for this.
:bowdown:
Its not completely quite, but the throttle didnt make it louder.

Why should it? Doesnt have a great influence on the air flow anyways.
Air regulators dont cause a vacuum in the engine. Its more of a stream
control that reduces the flow over the carburator needle. Not the amount
of air breathed by the car.


Added: Never drove a turbo - just talking about plain road car engines.

Is the kind of throttle inputs we have on sims (value wise, position, mostly linear etc) a good approximation of how a real throttle works?

I've often wondered if maybe some fuzzy logic, or some other smoothing (or an opposite to smoothing) sytem might represent a throttle more accurately?? At the moment is it simply a case of precisely transfering the pot value into a throttle value??

The steering has an analogue smoothing option for pot wheels. Would air intake etc in the throttle always be exact and unwavering? Or maybe the jittering of pedal pots gives us a comparible variance anyway.

:static::detective

sorry, just had to throw that 3rd smiley in.

Quote from tristancliffe :

The throttle (on a gasoline engine) controls a valve, usually a butterfly value or a slide valve, and controls ONLY the volume flow rate of air. In a carb it is the pressure drop across the venturi (which is affected by throttle position) that mainly controls the fuelling (on a simplified carb, obviously it's rather more complex than that), and an an injected engine it is either an electronic or mechanical system that decides how much fuel to inject based on throttle, load, rpms etc etc etc.

To say the throttle controls the fuel directly (as I understood you to have implied) is wrong.

Of course, wthout combustion there shouldn't be combustion sounds, but that is the limit of the LFS engine. But a real life engine will develop noises due to work on the air itself, and the volume/tone of that noise will be controlled by the throttle valve.

Take an engine. Remove fuel system. Spin engine (either via transmission and road friction or by alternative means) up to a decent speed, and it will make airy noises. Hell, get a tube with a piston in it, and move the piston - the tube will make a noise.

I never said LFS was perfect, just that it wasn't far wrong.

Actually on most injection cars, the injection is stopped when lifting the foot of the pedal ( engine braking ). And as you say, it still makes noises.

But actually i would think in two contradictory ways.
Indeed with throttle opened the engine doesn't have to force much the air in. But compression will be high since the air in the cylinder should be quite close to 1 bar at BDC.
At the contrary, with throttle closed, less air should be admitted and moreover the engine has to pump harder. Thus more frictions and forces that would create structure borne noise. But during the compression the forces should be lower, since the pression reached at TDC would be less.

So actually i don't know what to think

:munching_