More crazy 6.0 stuff

[HGM]

reason I asked was the big guys like cummins and detroit dont go into EGr mode unless some conditions are met, like above 1100 rpm, not full throttle and engine temp above a certain point.

I doubt EGR is effective at idle, they only use it to reduce NOx emissions,, which occur at high cylinder temps, which aren't a factor at idle.

also probably hard to get EGr flow at idle, due to low exhaust pressure.

whatever, really!, if it was mine I'd disconnect the stuff and figure out a way to recalibrate the ECM outta EGr mode. probably stick a regular wastegated turbo on the thing and call it good to go.

Well, dont forget too that EGR also reduces engine noise.. Its a benefit for a diesel to be "quiet" enough to run through the McDonalds drivethrough... Really, marketing plays a big part in this too..

 

[cp1969]

How does egr quiet the engine? I have always likened egr to running a tube from one's rear to one's nose and using that as part of your personal intake air. You wouldn't like it; I see no reason why your engine should, either.

 

[em14]

cp1969 ...
I'm going to be laughing for a month .. that's a great comment!
Leo

 

[HGM]

How does egr quiet the engine? I have always likened egr to running a tube from one's rear to one's nose and using that as part of your personal intake air. You wouldn't like it; I see no reason why your engine should, either.

EGR lowers combustion temperatures. It does this by displasing O2 in the combustion chamber with an inert gas. On a diesel(unlike a gasburner), there is an over abundance of O2. By diluting/reducing the O2 in the cyl, you can basicly reduce the size of the cyl... Less fuel + less air = less bang/less heat.. EGR can flow on a diesel under most operating conditions.

 

[KICK]

EGR can flow on a diesel under most operating conditions.

I dont think so.

think about it...

imagine a situation where you have 20 psi of boost pressure in the intake manifold and 1 psi in the exhaust system, how can the low pressure flow into the higher pressure area?


in order to make egr work, they need to create high exhaust back pressure.

in comes the "VNT" to create high exhaust back pressure.

they need the exhaust back pressure to be higher than the pressure in the intake manifold which is under boost.

in comes the" VNT" to regulate boost simultaneously with increasing the exhaust back pressure.

 

[KICK]

Well, dont forget too that EGR also reduces engine noise.. D

thats too funny.

the way the injection of fuel is accomplished accounts for most of the improvement

lots of the electronic controlled engines that are so quiet now have fuel delivered in more than one injection pulse

the injection is pulsed and timed over a longer period of time than it used to be

 

[HGM]

I dont think so.

think about it...

imagine a situation where you have 20 psi of boost pressure in the intake manifold and 1 psi in the exhaust system, how can the low pressure flow into the higher pressure area?


in order to make egr work, they need to create high exhaust back pressure.

in comes the "VNT" to create high exhaust back pressure.

they need the exhaust back pressure to be higher than the pressure in the intake manifold which is under boost.

in comes the" VNT" to regulate boost simultaneously with increasing the exhaust back pressure.

Maybe you need to think about it.. You just answered your own doubt... The VGT changes backpressure. As the backpressure is increased(into the 50+psi range under hard accell) EGR will most cretainly flow into the puny 32PSI intake pressure... I have recordings I can show you to prove it and a truck we can road test if your ever in the Atlanta area..

 

[HGM]

thats too funny.

the way the injection of fuel is accomplished accounts for most of the improvement

lots of the electronic controlled engines that are so quiet now have fuel delivered in more than one injection pulse

the injection is pulsed and timed over a longer period of time than it used to be

Yes you are correct that injection style and timing plays a HUGE part of the "noise" factor. But EGR does in fact lower noise as well.. If you have a tool that can command EGR flow at idle, try it sometime...

A diesel engine has an unrestricted flow of fresh air, unlike a gasburner. Even by cutting the fuel back, we still cannot control temperatures. So, by replacing the O2 with EGR, the whole combustion dynamic can be changed/taylored into the proper air fuel ratio. This can now be done throughout the whole RPM range. A diesel WILL flow EGR whenever the PCM decides it can do so without creating driveability concerns.

KICK, I respect your opinion and you certainly know what you are talking about on the big stuff. But once again, your assumptions that the smaller stuff opperates ecactly the same way are not correct.

 

[KICK]

A diesel engine has an unrestricted flow of fresh air, unlike a gasburner. Even by cutting the fuel back, we still cannot control temperatures. So, by replacing the O2 with EGR, the whole combustion dynamic can be changed/taylored into the proper air fuel ratio. This can now be done throughout the whole RPM range. A diesel WILL flow EGR whenever the PCM decides it can do so without creating driveability concerns.

.

it sure does have an unrestricted flow of air, it also doesn't have any vacuum to help pull anything into the intake,although engine does draw air in , main reason for vnt is to control the exhaust backpressure and the boost to give the ability to mix the burnt gases with the clean air when EGR is commanded by the ECM, Idle happens to be low boost and relatively low exhaust flow, also low cylinder temps, thats why egr is inneffective at idle, doesn't mean ford don't do it.

the proper air fuel ratio is determined by the amount of fuel injected into a cylinder, no stoichiometric fuel air ratio like a gasser.

the science behind EGr is that since it is already a burnt gas, it is inert and it helps lower peak combusture temperatures... if Ford needs it at idle, I'm sure they can command it. mostly been my experience they don't need it at idle, engine isn't doing very much wwork wise and running clean

 

[HGM]

it sure does have an unrestricted flow of air, it also doesn't have any vacuum to help pull anything into the intake,although engine does draw air in , main reason for vnt is to control the exhaust backpressure and the boost to give the ability to mix the burnt gases with the clean air when EGR is commanded by the ECM, Idle happens to be low boost and relatively low exhaust flow, also low cylinder temps, thats why egr is inneffective at idle, doesn't mean ford don't do it.

the proper air fuel ratio is determined by the amount of fuel injected into a cylinder, no stoichiometric fuel air ratio like a gasser.

the science behind EGr is that since it is already a burnt gas, it is inert and it helps lower peak combusture temperatures... if Ford needs it at idle, I'm sure they can command it. mostly been my experience they don't need it at idle, engine isn't doing very much wwork wise and running clean

OK...