Quote from Shotglass :

so in other words their efficiency is rubbish => turn it down a little => problem solved ... exactly what i said

ok but their efficiency is only rubbish when on boost

Can I buy co2 offsets for my FZ5?

My car went from 4,5 km/l (10,58 mpg/22,22222 and so on l/100km) in average to 3,5 km/l (8,23 mpg/28,57 l/100km) in average, when I went from carburator to fuelinjected turbo.

I really cant get it much higher, even if i drive very nice. I've had it up to 5,2 km/l (you do the math) max as turbocar, that was on a long trip with 130 km/h constant.

Quote from RevengeR :

Still, revs itself doesnt mean boost really builds up. Like you have the car in neutral, then rev it to lets say 4000 rpm, then load that engine (to be simple, be in gear and just step on the brake). In neutral, since its not under load, less A/F needed to get the revs, which equals in less exhaust. Then in the next case, when loading the engine, it does more work to maintain the same rev, which means more A/F, more exhaust -> the turbo effectively builds up boost.
Its not just about how fast it builds up the boost (because at 4000rpm in neutral you will not have boost effectively), but how much boost it builds up if it does any.

Like I have a supercharged 3.8 in my car. Since its a 'forced-fed' engine, we can talk about boost. During daily driving, I can simply drive without making any boost. No boost either when revving it in neutral. Boost only builds up when the engine is loaded.

Im not saying you are wrong, I just say revs itself doesnt mean theres built up boost in the cylinder head. Also, cruisin at 60 km/h at 3000 revs wont make boost building up, not even slowly. Load is what you ned when you want to build up boost.

PS: ah, sorry, seems like I totally misread the facts, and wanted to prove the opposite. You have to excuse me, its 5:15 am

Are you fricken kidding me? Ofcourse i know RPM =/= boost.... :doh:

The first thing you are trying to "prove me wrong" with is completely stupid. You are comparing building boost without load and building boost with load.

Quote :

In neutral, since its not under load, less A/F needed to get the revs, which equals in less exhaust. Then in the next case, when loading the engine, it does more work to maintain the same rev, which means more A/F, more exhaust -> the turbo effectively builds up boost.

In neutral, less A/F ratio needed to get the desired RPM??... uh no. I hope you meant throttle position. If not, you need to stop posting in these forums before you turn into a complete moron. Here ill fix it for you.

"In nuetral (engine has no load), less throttle is needed to reach a desired RPM, which means less fuel needs to be burnt, and less exhaust will be produced....
...Under load, more TPS is needed to reach a desired RPM, which means more fuel needs to be burnt, and more exhaust will be produced. **** RESPECTIVELY ****"

In order for your engine to see boost, your throttle butterfly needs to open up to allow air to enter. In most turbo cars (except insanely undersized turbos for the motor, which is the case with most large diesel trucks), you can essentially go to redline (definetly in nuetral, possible under loaded conditions) without any positive manifold pressure. If this wasnt the case, then your car would never be able to see redline in N/A form, and you would have a serious problem, or that engine is completely inefficient.

Sorry to tell you, but your idea about your supercharged 3.8 is wrong. You dont see boost in a supercharged application when cruising because your TPS isnt opened very much and the air that the supercharger is flowing is being blocked by the throttle butterfly. Where does it go? Well, a tiny bit is getting by the butterfly, a tiny bit is going through the IAC, and the rest will go out the bypass/blowoff valve if your setup uses one... if not, it escape back passed the compressor fins and you most likely experience compressor surge. Building boost in a supercharged car has nothing to do with load because your supercharger's RPM is directly proportional to the engine's RPM... it has everything to do with throttle position.

Do yourself a favor and stop trying to copy off a stupid wikipedia website or some other damn website that doesnt know what they are talking about. Go out and try to learn this stuff before you try to act like you actually know the stuff. You just make a complete fool of yourself.

Can peoples become any more stupider?

This seems like a lot of work, but is really cool. Keep on going!

It's been done numerous times before, but most have lost the energy from repeating ad infinitum.

It's just not worth it. *sigh*

Quote from theycallmeebryan :

Are you fricken kidding me? Ofcourse i know RPM =/= boost.... :doh:

The first thing you are trying to "prove me wrong" with is completely stupid. You are comparing building boost without load and building boost with load.



In neutral, less A/F ratio needed to get the desired RPM??... uh no. I hope you meant throttle position. If not, you need to stop posting in these forums before you turn into a complete moron. Here ill fix it for you.

On A/F I wanted to say air and fuel, not the ratio of the mixture. And if you read down a bit, you would see that I misread your post. And no, I didnt copy nothing from wiki. As I said, I just misread it. Read it twice next time

ps: Yep, I admit I was wrong with the supercharger, its quite a rare stuff over here, so I just havent experienced it so far. Ppl learn from their faults :P

Quote from theycallmeebryan :

Can peoples become any more stupider?

I wouldn't go so far as calling people stupid, it is just that many don't know much how stuff works, of course wise mens are quiet until they are sure they know stuff in question, but I think we have passed that era, now it is F&F type of realism and knownledge era, which is of course shite, but what can you do, times do change.

One thing I have learned is that no matter how well you do explain things you will find similar thread soon again with similar debates

Quote from JTbo :

I wouldn't go so far as calling people stupid, it is just that many don't know much how stuff works, of course wise mens are quiet until they are sure they know stuff in question, but I think we have passed that era

I don't know about that... I mean, the Earth was originally believed to be flat.

Quote from theycallmeebryan :

Are you fricken kidding me? Ofcourse i know RPM =/= boost.... :doh:

The first thing you are trying to "prove me wrong" with is completely stupid. You are comparing building boost without load and building boost with load.



In neutral, less A/F ratio needed to get the desired RPM??... uh no. I hope you meant throttle position. If not, you need to stop posting in these forums before you turn into a complete moron. Here ill fix it for you.

"In nuetral (engine has no load), less throttle is needed to reach a desired RPM, which means less fuel needs to be burnt, and less exhaust will be produced....
...Under load, more TPS is needed to reach a desired RPM, which means more fuel needs to be burnt, and more exhaust will be produced. **** RESPECTIVELY ****"

In order for your engine to see boost, your throttle butterfly needs to open up to allow air to enter. In most turbo cars (except insanely undersized turbos for the motor, which is the case with most large diesel trucks), you can essentially go to redline (definetly in nuetral, possible under loaded conditions) without any positive manifold pressure. If this wasnt the case, then your car would never be able to see redline in N/A form, and you would have a serious problem, or that engine is completely inefficient.

Sorry to tell you, but your idea about your supercharged 3.8 is wrong. You dont see boost in a supercharged application when cruising because your TPS isnt opened very much and the air that the supercharger is flowing is being blocked by the throttle butterfly. Where does it go? Well, a tiny bit is getting by the butterfly, a tiny bit is going through the IAC, and the rest will go out the bypass/blowoff valve if your setup uses one... if not, it escape back passed the compressor fins and you most likely experience compressor surge. Building boost in a supercharged car has nothing to do with load because your supercharger's RPM is directly proportional to the engine's RPM... it has everything to do with throttle position.

Do yourself a favor and stop trying to copy off a stupid wikipedia website or some other damn website that doesnt know what they are talking about. Go out and try to learn this stuff before you try to act like you actually know the stuff. You just make a complete fool of yourself.

Can peoples become any more stupider?

well, that basically proves that i was right. I was going to say that by the logic of the people who said that load=boost, no exhaust gasses are produced in neutral/clutch in. Of course gas is produced in neutral, are you guys suggesting that since there is no load, petrol suddenly doesn't produce a gas when burned? Petrol will produce the same amount of gas when burned, regardless of load. RPM controls how fast new gas is produced, controlling how fast the turbo spins, correct?

:sadbanana

Quote from dougie-lampkin :

are you guys suggesting that since there is no load, petrol suddenly doesn't produce a gas when burned?

But by definition there is no such thing as "no load" no matter what there will be friction. Usually, when people say "no load" they are not counting the load of the friction in the engine.

Quote from wheel4hummer :

But by definition there is no such thing as "no load" no matter what there will be friction. Usually, when people say "no load" they are not counting the load of the friction in the engine.

Oh, shut up. That's like saying that night time should be called daytime because there is ambient light. Of course there is friction, but it's pretty negligable. Carry on like this and there'll be a LFSForum Petition to re-ban W4H

Quote from dougie-lampkin :

well, that basically proves that i was right. I was going to say that by the logic of the people who said that load=boost, no exhaust gasses are produced in neutral/clutch in. Of course gas is produced in neutral, are you guys suggesting that since there is no load, petrol suddenly doesn't produce a gas when burned? Petrol will produce the same amount of gas when burned, regardless of load. RPM controls how fast new gas is produced, controlling how fast the turbo spins, correct?

Correct, there is exhaust gas - put your hand over an exhaust whilst someone revs it in neutral and you'll feel it. But that exhaust has very little energy to it, because the throttle wasn't opened (so not much fuel was used). You can't use full throttle for more than a second otherwise it'll rev too much. Sitting on a rev limiter at full throttle in neutral will cut the sparks (and hence the energy in the exhaust gas). And turbos are driven more by the heat of the exhaust gas than the flow of it.

All of the above (and more) means that turbos don't generate boost in neutral. And I'm a complete fool when it comes to Turbos. The ones that know are slapping their foreheads again. One is a sad banana.

Sorry, I may have come across wrong as suggesting that neutral generates boost, I was just using that as an example. But what I am saying is that an engine will generate gas, regardless of the load, as load is not proportional to boost, as was suggested earlier by several people.

BTW, out of curiousity, what was W4H banned for?

W4H was banned for being an asshat, in short.

you can generate boost in neutral just not practically. as said before if you revved in neutral you'll hit the red line in a second. At redline Fuel and ignition are cut if you kept it there it would slowly build boost. but seldom would you ever want to launch at red line. if you have a two step launch control you could build boost in at a lower RPM. Eg a STi with launch control set at 4500 Rpm will make 8 PSi and but no more.

Quote from Voytech :

You can't be serious.

Yes, he IS serious, and he's technically quite correct I'm afraid.

Judas Priest...

The turbine side of a turbocharger is not driven like a pinwheel you find at the fair, although I can understand why people think that. Of course, there is some component of plain kinetic transfer but in fact it's quite small (I forget the typical numbers but it's not much).

Exhaust gases are very hot, and with that comes pressure (heat/pressure is the key). It is in fact the expansion of gasses inside the turbine that causes the vast bulk of energy transfer, and without heat that does not happen. In essence, it's working off of a pressure differential between the inlet side and the outlet side of the turbine housing. This is why you want large diameter plumbing on the outlet side, so that the pressure differential is greater and spool times are quicker (as opposed to an NA engine where you'd want proper diameter/length tuning for pulses etc). Just think of it as a compressed gas exerting pressure on a closed container - except that the container isn't closed, one side of it happens to move and one side is open.

If you think that the heat is not the dominant factor, simply play with a turbocharger on a bench - you can blow ambient temp air through it, and yes, it will move somewhat... However you can use a blowtorch to put much LESS air through it, and spin the thing up like crazy using far less "flow".

Predominantly, you're converting thermal energy (not heat if you want to be freakin anal) in to kinetic energy. No thermal energy, no happy fun times with your turbo. Burn more gas=make more thermal energy in the same little space = more pressure differential = more boost = more gas etc etc, a positive feedback device - unlike in LFS where boost is delivered linearly and then the increase tapers off.

Quote from Jakg :

W4H was banned for being an asshat, in short.

lol, will probably happen again soon!!!

Quote from tristancliffe :

That's like saying that night time should be called daytime because there is ambient light.

Not at all actually. Where exactly did I say that "there is a small amount of friction in your engine, so it is constantly at maximum load?"

I've done some experimenting of my own, and I have concluded that the XRT IS more economical than the XRG at city driving. I did one lap in each around kyoto ring, with 6.5 litres of fuel in each (10% in XRG, 12% in XRT). I used the original hard track setup for each car. I gave each car full throttle up to 3000rpm, then changed up, with no flat shifting. I continued this up until 70mph (+/- 1) when I used the throttle at around 33% (don't know exact figure) to keep it at 70mph(+/- 1). I kept each car in the middle lane. Here are my results:

XRG - 0.3% of full tank = 0.195 litres
XRT - 0.2% of full tank = 0.150 litres

Considering the XRT is 200cc more than the XRG, I think that that finally concludes that turbo cars ARE indeed more economic than non-turbo cars.

Now, here come the accusations of a spoiled test......

EDIT: I forgot to mention that I did this test with 100% fuel in each car and got the same results. Not that it matters.

Quote from dougie-lampkin :

Considering the XRT is 200cc more than the XRG, I think that that finally concludes that turbo cars ARE indeed more economic than non-turbo cars.

The XRT uses 0.77% less fuel then the XRG, is that really very conclusive evidence? Because, the difference between the final drive ratio of the XRT and the XRG is 0.81%.

Quote from wheel4hummer :

Not at all actually. Where exactly did I say that "there is a small amount of friction in your engine, so it is constantly at maximum load?"

My point was why even mention internal friction when even a 2 minute old fawn would realise. You're trying to be smart, because it's the only thing you ever add to technical discussions other than giving some of us a change to giggle at you.

We better stop this thread, it's caused Tristan to lose his short term memory!
(ps hope you feel better soon)

I may have to employ the ignore function soon, something no one has ever driven me to before.

Quote from wheel4hummer :

The XRT uses 0.77% less fuel then the XRG, is that really very conclusive evidence? Because, the difference between the final drive ratio of the XRT and the XRG is 0.81%.

That doesn't matter, I didn't adjust ANY settings, so therefore the turbo is more efficient than the non-turbo, regardless of gearing, as it would be that way on a real turbo car.

Quote from Ball Bearing Turbo :

We better stop this thread, it's caused Tristan to lose his short term memory!
(ps hope you feel better soon)

I may have to employ the ignore function soon, something no one has ever driven me to before.

lol, this has gotten quite out of hand alright!