Quote from wheel4hummer :

Well, I am talking about the volume of air after the intake. Because the volume of air that is sucked into the intake is smaller, and then the air contained in that volume is expanded when it is sucked through the intake tube and throttle body. So if you mean the volume of air that starts out outside of the intake and then is expanded when it gets sucked into the intake, then I agree. I just realized where I may have been really confusing. lol

I realy don't know how to explain it so you will understand, it's kind of frustrating.

If the pressure is lower inside the intake, then you have less volume of air, because at 1 atmosphere that volume of air will take up less space.

meaning that it's the opposite of compressing the air, if you compress the air, then at 1 atmosphere of pressure, the air will take up more space.

This is partly why an engine makes more noise with the throttle open as it does with the throttle closed at the same RPM, because the engine is getting more air/fuel, and thus better compression and ignition.

Quote from ssm :

Second of all, this is a BIIIIG tangent to my original post. I just wanted to post a suggestion for some improvement ideas that might catch the attention of the Devs. I lurked about the older forum posts a bit, it looks like many people are ALSO looking for brake fading. I am hoping that brake fading, "sponging", and damages will be included in the next update.

not to be an ass, but most of that has been suggested a million times, and discused untill dead.

Last edited by DragonCommando, Tue, 5 Aug 2008 23:20.

Quote from wheel4hummer :

How is that possible? I'm talking about volume, not amount of air molecules!!!! If you are filling a 3 liter container with air, and you have a valve at the top which controls how fast air goes into it, the container is still 3 liters even if you close the valve 50%, is it not? It just takes longer for the pressure to build in the container if the valve is closed 50%, and therefore in a given amount of time, it would contain a lower amount of air molecules then if the valve was fully open. But either way, it is 3 liters of air, but since the pressure is higher, there is a greater amount of air molecules if the container had it's valve fully open for an equal amount of time.

EDIT: Although, I just realized that in an engine there are pistons, and the volume of them changes as it goes on the intake stroke. When I mention volume, I mean when the piston is at bottom dead center. Because, I guess the volume of the engine constantly changes. But, even so, the only thing that effects the volume of an engine is the position of the crankshaft, since that moves the pistons thereby changing their volume. Combined with the fact that one piston may be on it's intake stroke while another is on a different stroke. But again, the engine doesn't get any smaller if you use less throttle. I understand that I am being given a hard time just because this is an online forum, and that is to be expected. Also, no-one is understanding what I am writing, and they think something completely different then what I am typing. Life is a huge misunderstanding, it seems. You can't expect to understand everyone, and you can't expect everyone to understand you either.

The actual pressure is different, so the air volume at 1 atmoshere is different. Though the intake won't be at 1 atmoshere unless the engine isn't running at all.

What I mean is, if the throttle is closed, less air goes into the engine even if the RPM is the same, you get less air volume into the engine. If you open the throttle, even if the RPM doesn't change, vacuum decreases and you get more air volume into the engine.

Quote from ssm :

How is that not relevent? The more load, the more fuel you need to burn to reach a certain engine RPM.

see, that makes sense, why didn't you just say that.

Quote from wheel4hummer :

I know, I was just saying that the engine takes in the same volume of air regardless of throttle. But people misunderstood me and thought that by saying "volume" I meant "amount of air molecules", but that is not the case. I meant volume as in space occupied by something.

But the engine doesn't take in the same volume with different throttle positions, even if the engine RPM is the same. At idle, the engine is taking in less air with the throttle closed as it is with the throttle open. even if the engine doesn't accelerate. ofcourse, that only happens under a load that balances out the power with the resistance.

Quote from wheel4hummer :

How is that relevant?

Its not.

But what you said doesn't quite make sense either.

The faster the engine revs, the more air and fuel gets taken in, and the farther open you keep the throttle, the higher up the vacuum balance will be, so the engine will suck in more air, but the vacuum will balance out and maintain the speed of the engine.

In alot of older model cars and some newer cars with horrible syncronization, it was and can sometimes still be a benefit to double clutch. Many transport trucks still require you to double clutch, because they run unsyncronized transmissions with straight cut gears.

Double clutching on upshifts gives the engine time to slow down and match the speeds in the transmission.

Because your input shaft is now spinning faster than it will be when you engage the next gear, you need to slow it down. so you disengage the gear you are shifting out of, leave it in nutral and release the clutch, as soon as the engine slows down to the speed for the next gear it will have taken the input shaft with it, allowing you to put it in gear even without using the clutch, though it would probably be a good idea.

On a car with very fast throttle responce it only takes an instant for the engine to rev back down to match the speeds. So your shift will still be just as fast unless you where using the clutch to match speeds before.

double downshift? do you mean double clutching? because thats only done when you upshift. For downshifts you have to blip the throttle, and you don't even have to use the clutch. Just release the throttle, put it in nutral, blip, and stick it in gear. If done right, it will just slide into gear, no syncros needed.

If you want to make it more realistic, just have gradual wear, there isn't much you can do to screw up a shift badly enough to break something.
you can do it, but its not as simple as screwing up a shift.

You usualy feel the grinding in the stick more than you hear it (at least in the cars I drove), and if it does grind, its not doing much damage unless you shift like a gorilla.

If you want realistic shifting, you need realistic shifters, that can prevent you from clicking it into gear if it doesn't line up, and unfortunately they don't have those yet.

I would love if when I buy my license I could hop in a high powered muscle car.

Just imagine the challenge of getting the monster to corner, you'd be fighting oversteer like crazy in the corners and just lugging it around the track. It would add one hell of a challenge for even the more experianced drivers.

As for setup, it would have very little rear end adjustment since it would probably have a simple setup, even leaf springs would be logical for an older model muscle car.

Something like a hemi cuda or even a 70's charger comes to mind, of course, it has to be completely custom.

I wouldent like the auto box though, theres just something about "four on the floor" that has a ring to it.

Thats been suggested before though.

Quote from james12s :

well i didnt make it up(someone else may have), its something ive been told by someone who doesnt useually make things up, but i may be wrong i dont know but it seems posible that some cars would have it seeing how nanny state-ish cars are getting, you cant fart without the car warning you its flammable(or possibly)lol

Its a bit more complicated than cutting ignition when you put the clutch peddal down, It actualy reduces throttle. This system will only be pressent on cars that have electronic throttles, drive by wire throttles as they call them here. What it actualy does is let you shift with your foot down on the accelerator peddal, so you never have to lift. But it also does a good job of keeping the boost up on a turbo, which is partly what it is for.
Basicaly, the computer matches the revs for you.

I hate newer cars sold here because of the idiot proofing they have, and it seems to get worse by the year.

now they have cars with rev limiters that let you flatshift! They don't cut ignition, they limit the revs so the car will go from one gear to another without jumping, and you don't have to release the throttle, ever.
It's like they want people to be idiots.

Thats true, but in the case of a waste gate, its easier to manage one, so one big one will generaly be better than 2 smaller ones. All you have to do to contol boost is control pressure on one valve, and generaly, the less moving parts, the more reliable it will be.

If you can fit 2 wastegates, you can fit one big one. This is even more true on high boost applications where the turbo and exhaust will be much bigger.

I have only ever seen dual waste gates on dual turbo systems with a small and large turbo.

Unless you are talking about dual port external wastegates, but to my knowlege, the second port serves a different function and isn't needed for proper functionality of the wastegate.

Quote from MAD3.0LT :

hahahahahahahahhahahahaahahah

jajajajajajajajajajajjajajajaja

fuk this is amusing to read
i thought i was dumb (maybe i still am )

their is many ways to controle boost and vary intake pressures but personaly id prefer a externaly wastegate or even 2 on a 4 inch dump with a 2 and a half inch wastegate pipe but thats costly and ilegal here

2 wastegates? You can't mean on the same turbo, that would be completely pointless. One wastegate, controlled by the management computer, is all you need. And all I've ever seen on turbo charged race cars. That means no fancy crap that lets you change boost from inside the car either, boost controlers are useless if the engine management can do it already.

Last edited by DragonCommando, Tue, 15 Jul 2008 03:26.

Quote from tristancliffe :

I think by boost controller he meant the electronic version, and wasn't referring to the obligatory wastegate.

I don't love the sound of atmospheric blow off valves. They generate the sound known to me as 'pure moron'. Only an idiot would fit one on a road car in place of a recirculating valve.

Thats exactly what I meant, and I agree about the blow off valves as well. I hate that sound almost as much as I hate the sound of a car without any valve. Compressor surge/stall is bad, period. If your car makes a funny fluttering sound when you let off the throttle, there is something wrong.

Last edited by DragonCommando, Sun, 13 Jul 2008 20:04.

Quote from wheel4hummer :

/facepalm

I was wondering when someone would use that picture.

I'm realy considering making an animated diagram of the system, so people will stop mentioning wastegates and BOVs and trying to explain the function of each, and failing horribly at it.

A wastegate is on the exhaust side, a blow off valve is on the intake side.

The wastegate is used to contol boost. It is run by a pressure line going from the charge side of the turbo to the wastegate. Boost controlers just change the pressure on the wastegate, so you can obtain a higher boost before it opens, or limit boost by running a weaker spring in the wastegate and compensating for it with the controler when you need more boost.
Wastegates also prevent the turbo from overspeeding, which can cause damage or even failure. If you've ever seen a turbo explode, I can garantee it was because it was spinning faster than it was designed to.

Generaly high performance race cars won't need boost controlers, unless they are bracket racing drag cars. If you have a boost controler on a road car, it's simply for show and serves no function other than to say "I have a boost controler, I'm cool":rolleyes:

The blow off valve serves a completely different function and controls boost during throttle off, there are no servos or switches of any kind on the bov, just a single vacuum line going to the intake after the throttle plate.

Quote from Crashgate3 :

You laugh, but a fair amount of the emails I get at work are like this.... it's enough to make you want to weep.

The sad part is, some schools are starting to allow the use of this for tests and assignments. One girl wrote a whole short story like that.

It's just getting mental now.

Quote from MAD3.0LT :

and i can go from -20 vacume to -2 vacume free reving the engine

This is because the engine doesn't respond as fast as one with more than a fue performance bolt ons, if the whole inside of the engine has been replaced with stronger but lighter parts, the vacuum will not drop as much. It will still drop, but not as much, sometimes not enough to close the BOV.

This doesn't hurt anything since you don't need boost if you are just reving for kicks n' giggles.

However, from what I'm getting from what you people are saying about the turbos in LFS. There apears to be two problems, one is that the turbo lags alot, and the other is that they all act as if the car can maintain enough vacuum to prevent the boost from being used.

Well, it realy depends on how quickly the engine responds to throttle position, if it responds slower than you can get positive manifold pressure in nutral. but on a car that responds very quickly the engine will keep up and you will only get a small drop in vacuum.

If you put a turbo on a formula 1 engine or an engine with similar responce time I'm positive you won't get boost in nutral. The turbo will spool, theres no question about that, but the valve won't close bacause of vacuum.

For the most part, stock turbos don't have blow off valves, they have recirculating valves, so it doesn't matter if its open or not, it's always filtered.

But a performance turbo usualy has a blow off valve, which in most cases has it's own filter to prevent dust from being sucked in at idle. But some people like to hear that noise made popular by a particular movie, and run a blow off valve with no filter without realizing what they are risking.

When you go WOT from a stand still in gear the vacuum will drop almost instantly and boost can then build as soon as the turbo spools, because the engine has a load on it and will not just rev up as fast as it can.

If you go WOT with the car out of gear, the engine has no load and will then wind up as fast as it can, usualy keeping up vacuum. This causes the valve to either only close partialy, or not at all. Which means that even though the turbo is spooling up, the boost is lost through the valve.


So the turbos in LFS behave quite realisticaly in that sence, if you just WOT out of gear the engine will keep up with the vacuum drop, and it won't drop enough to close the valve.

I could provide a diagram of the system, but it would take some time to make. It would more than likey need to be animated to show without load, and with load.

Last edited by DragonCommando, Mon, 7 Jul 2008 21:48.

Quote from morpha :

I think we're talking about different ways of testing here.
You're trying normal, linear acceleration, basically building up speed rather than turbo pressure. I go for turbo pressure rather than speed

To get 1.7 bar in 1st @ 5000, I actually have to left-foot brake to keep the revs @ 5000 while still applying full throttle. If I just go for it and accelerate like I normally would, my results pretty much match yours.

Click me, I'm a video! ... showing how I drive when I'm concentrating on a little read-out instead of the tarmac I'm meant to stay on

And this is because you are putting a high load on the engine (by braking and accelerating at the same time)
The high load keeps the engine from accelerating and maintaining vacuum, because the throttle is open, the blow off valve closess and you get higher boost.

I should have made it clear in the beginning, but I was rushing.
Sorry about that.

Vaccum will not slow down a turbo and more than likely would assist it in spooling since you are drawing air through it in the direction it is designed to push air.

If there is little or no load on the engine then vacuum will still be too high to close the blowoff valve completely and you will lose boost. Atleast untill you get near the maximum speed the engine can rev with the intake size it has. which would be a bad idea since thats usualy well above redline.

When a Turbo equiped car is idleing the blow-off valve is sitting open, when the vaccum drops off as the engine speeds up the blow off valve closses. The blow off valve and turbo spooling rate/time are completely seperate from eachother, and as soon as you get vacuum again the blow off valve will open regardless of boost or not.

When Demo had a turbo the only thing wrong that I noticed was the lag.

Last edited by DragonCommando, Sun, 6 Jul 2008 21:19.

Mip maps work on a set of distance planes, so the texture actualy gets lower resolution at each of these planes. Because it is using a smaller mip map as you get farther away.

So for instance, if the object is on the plane with half on the far side and half on the near side, the half closest will be drawn with a bigger texture (mip map) than the half farther away. Thats why you see lines on the ground in games where the texture gets less detailed with each line.

Its a bit more complicated than that, but at the very basic thats how it works.
It has no ties to polygons at all if my memory is correct.

Then they are already used.

I forgot that LFS now uses DDS for skins. If it was jpg, then it would either have to calculate when loaded, or not use them at all.