EGR ALS- Explain please
09-04-2006, 08:00 PM
#1
DEYTUKURJERBS
Thread Starter
EGR ALS- Explain please
I still have no idea how it works.
Someone tell me please, in detail.
No just giving clues (gareth
) as im not one for thinking today, ive been sick about 20times and still feel rough now.
And does it work in conjunction with, or instead of, normal ALS.
Thankyou.
Someone tell me please, in detail.
No just giving clues (gareth
) as im not one for thinking today, ive been sick about 20times and still feel rough now.And does it work in conjunction with, or instead of, normal ALS.
Thankyou.
09-04-2006, 08:17 PM
#2
EGR: exhaust-gas recirculation
A method of reducing NOx (oxides of nitrogen) exhaust emissions by recirculating some of the engine's exhaust gas into the intake manifold. The exhaust gas serves as inert filler that absorbs heat during the combustion process and reduces the peak temperature reached during combustion.
A method of reducing NOx (oxides of nitrogen) exhaust emissions by recirculating some of the engine's exhaust gas into the intake manifold. The exhaust gas serves as inert filler that absorbs heat during the combustion process and reduces the peak temperature reached during combustion.
09-04-2006, 08:18 PM
#3
Professional Waffler
right firstly i have never been told how it works,, i just sat down and thought about it a little!
i jumped too the conclusion that what you are doing is turn the turbo into a turbine engine,,, this is done by piping the outlet of the compressor into the inlet of the turbine housing! because the exhaust gets a little hot, the only valve you could really use form a car is a EGR valve (hence the systems name)
if we add a little ignited fuel (from the engines injectors, standard als system) into the middle of the bypass between turbine and compressor we car get a small burn going on which will drive the turbine wheel,,, and because the turbione and compressor are connected, more air will be bypassed, wih more ignited fuel from the standard als, the turbo shaft speed just gets faster and faster
i may be well off the mark,,, but thats how i understand it
i jumped too the conclusion that what you are doing is turn the turbo into a turbine engine,,, this is done by piping the outlet of the compressor into the inlet of the turbine housing! because the exhaust gets a little hot, the only valve you could really use form a car is a EGR valve (hence the systems name)
if we add a little ignited fuel (from the engines injectors, standard als system) into the middle of the bypass between turbine and compressor we car get a small burn going on which will drive the turbine wheel,,, and because the turbione and compressor are connected, more air will be bypassed, wih more ignited fuel from the standard als, the turbo shaft speed just gets faster and faster
i may be well off the mark,,, but thats how i understand it
09-04-2006, 08:21 PM
#4
Professional Waffler
Originally Posted by Andy_R
EGR: exhaust-gas recirculation
A method of reducing NOx (oxides of nitrogen) exhaust emissions by recirculating some of the engine's exhaust gas into the intake manifold. The exhaust gas serves as inert filler that absorbs heat during the combustion process and reduces the peak temperature reached during combustion.
A method of reducing NOx (oxides of nitrogen) exhaust emissions by recirculating some of the engine's exhaust gas into the intake manifold. The exhaust gas serves as inert filler that absorbs heat during the combustion process and reduces the peak temperature reached during combustion.
i know karl dont like calling EGR ALS, egr as it confuses the matter, which is fair enough
09-04-2006, 08:24 PM
#5
DEYTUKURJERBS
Thread Starter
cheers gareth, but surely thatd make the EGTs even higher than with normal ALS, but reading the lil bit of blurb on the mountune site it says it lowers EGTs
ive read a few things on the net about it, but same as with most ALS descriptions on there, im not convinced any of it is correct
ive read a few things on the net about it, but same as with most ALS descriptions on there, im not convinced any of it is correct
09-04-2006, 08:42 PM
#7
Another quote for you Steve, I dont pretend to understand how it works but am interested in learning, hope the following is of use.
Now, antilag - there are lots of different forms of anti-lag. All are designed to increase exhaust gas volume at low engine rpm:
1) Jacked-open throttle - basically, you jack the throttle plate open so it never shuts, and fit a rev limiter so that the car does not rev it's nuts off at idle. This gives you more exhaust gas flow, as you are always effectively accelerating. Downside is braking issues (no vacuum, so either a vacuum pump or servoless brakes are required). With this system you would also retard ignition timing at low loads and low rpm, so that fuel burns in the exhaust manifold. This is possible with a standard ECU, but it is on all the time - making the car a pig to drive and limiting turbo life severely! You could use a choke cable or similar to manually jack the throttle open, but you could not turn the ignition retard off, so would lose responsiveness off boost.
2) Air bypass - similar to the above, but the throttle plate stays shut and a solenoid operated air bypass opens to allow air to flow into the engine. The ECU would then (using a switch to operate it) retard ignition, and operate the bypass at certain throttle openeings - this works like above, with unburnt fuel entering the exhaust manifold and burning there. Good thing is the ECU can turn it off with high EGT temperatures, or manually with a switch (depends on ECU). Must have an aftermarket ECU for this. EVOs have an idle speed control unit which bypasses air into the intake manifold when cold, at idle. This is often used for ALS purposes too - but in reality doesn't really flow enough air. A proper bypass system uses huge pipes and fist sized solenoids!
3) AIR - Air Injection Reaction
This is normally used for emissions purposes. At low rpm, especially with engines with alot of cam overlap, unburnt fuel will exit via the exhaust. Injecting air under pressure into the manifold will result in the air reacting with the unburnt hydrocarbons, and the extreme manifold heat, resulting in an afterburn effect - which gives more exhaust volume s, and quicker spool up. The injector itself is usually an issue as it does act as an obstruction in the exhaust manifold, possibly adding to backpressure. A better way to do this is to feed compressed air from the turbo via an ECU controlled EGR valve for a higher volume of air, turning it off at peak loads to avoid increasing backpressure. This is great as the afterburn is much kinder to the turbo, and doesn't affect the engine's normal running (no remapping). This could be added to a standard ECU engine if controlled by a seperate device.
4) EGR (Exhaust Gas Recirculation)
Here exhaust gas is metered intdo the intake system. This is not as crazy as it sounds! At low rpm, the exhaust gas is full of hydrocarbons and heat, so helps excite the fuel air mix going in resulting in more volume, better burning and increased exhaust gas volume. It must be turned off at peak loads to allow for full cylinder filling. This really requires a non-standard ECU to control properly and because the car would need to MAP sensor operated.
The EVO actually has a standard a SAS (Secondary air system) which is there for emissions. It only operates at full throttle and above 4000rpm. If this was changed to operate full time at low rpm it would make an effective ALS system without hurting the turbo.
Another thing, for MAP sensored cars, is to use a recirculating dump valve and recirculate into the exhaust manifold (poor man's EGR system).
Now, antilag - there are lots of different forms of anti-lag. All are designed to increase exhaust gas volume at low engine rpm:
1) Jacked-open throttle - basically, you jack the throttle plate open so it never shuts, and fit a rev limiter so that the car does not rev it's nuts off at idle. This gives you more exhaust gas flow, as you are always effectively accelerating. Downside is braking issues (no vacuum, so either a vacuum pump or servoless brakes are required). With this system you would also retard ignition timing at low loads and low rpm, so that fuel burns in the exhaust manifold. This is possible with a standard ECU, but it is on all the time - making the car a pig to drive and limiting turbo life severely! You could use a choke cable or similar to manually jack the throttle open, but you could not turn the ignition retard off, so would lose responsiveness off boost.
2) Air bypass - similar to the above, but the throttle plate stays shut and a solenoid operated air bypass opens to allow air to flow into the engine. The ECU would then (using a switch to operate it) retard ignition, and operate the bypass at certain throttle openeings - this works like above, with unburnt fuel entering the exhaust manifold and burning there. Good thing is the ECU can turn it off with high EGT temperatures, or manually with a switch (depends on ECU). Must have an aftermarket ECU for this. EVOs have an idle speed control unit which bypasses air into the intake manifold when cold, at idle. This is often used for ALS purposes too - but in reality doesn't really flow enough air. A proper bypass system uses huge pipes and fist sized solenoids!
3) AIR - Air Injection Reaction
This is normally used for emissions purposes. At low rpm, especially with engines with alot of cam overlap, unburnt fuel will exit via the exhaust. Injecting air under pressure into the manifold will result in the air reacting with the unburnt hydrocarbons, and the extreme manifold heat, resulting in an afterburn effect - which gives more exhaust volume s, and quicker spool up. The injector itself is usually an issue as it does act as an obstruction in the exhaust manifold, possibly adding to backpressure. A better way to do this is to feed compressed air from the turbo via an ECU controlled EGR valve for a higher volume of air, turning it off at peak loads to avoid increasing backpressure. This is great as the afterburn is much kinder to the turbo, and doesn't affect the engine's normal running (no remapping). This could be added to a standard ECU engine if controlled by a seperate device.
4) EGR (Exhaust Gas Recirculation)
Here exhaust gas is metered intdo the intake system. This is not as crazy as it sounds! At low rpm, the exhaust gas is full of hydrocarbons and heat, so helps excite the fuel air mix going in resulting in more volume, better burning and increased exhaust gas volume. It must be turned off at peak loads to allow for full cylinder filling. This really requires a non-standard ECU to control properly and because the car would need to MAP sensor operated.
The EVO actually has a standard a SAS (Secondary air system) which is there for emissions. It only operates at full throttle and above 4000rpm. If this was changed to operate full time at low rpm it would make an effective ALS system without hurting the turbo.
Another thing, for MAP sensored cars, is to use a recirculating dump valve and recirculate into the exhaust manifold (poor man's EGR system).
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09-04-2006, 09:12 PM
#8
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I think the only reason its called EGR ALS is because it uses an EGR valve......
It doesnt recirculate the exhaust gases in any way.....it just happens that an EGR valve is plumbed in about right to use it for antilag. lol
I presume you could use AIR (Air Injection Reaction) in a similar fashion (although air injection would remain constant unlike with an EGR system), but i dont know how many cars come with that.
EDIT: eek,....i must have completely blanked your post Andy. sorry mate. lol
It doesnt recirculate the exhaust gases in any way.....it just happens that an EGR valve is plumbed in about right to use it for antilag. lol
I presume you could use AIR (Air Injection Reaction) in a similar fashion (although air injection would remain constant unlike with an EGR system), but i dont know how many cars come with that.
EDIT: eek,....i must have completely blanked your post Andy. sorry mate. lol
09-04-2006, 10:13 PM
#9
Advanced PassionFord User
EGR on the WRC car is used in conjunction with normal modified ISCV als...we actually use a Focus WRC EGR as the mountune item is shite....air driven affair....the focus is electric/electronic..a very trick valve with a solid state relay controlling it....it basically blows air from the hot side induction pipe (before the intercooler) into the four branches of the exhaust manifold...the mountune item only uses 2 ports....hard to quantify in performance terms it also aids throttle response....and egt's are 800 - 1000 degrees...als and egr on....
HTH
Ian
HTH
Ian
09-04-2006, 10:15 PM
#10
DEYTUKURJERBS
Thread Starter
So the inlet pressure is higher than the exhaust pressure?
As surely itd flow from exhaust to inlet otherwise.
I always thought it was the other way round?
As surely itd flow from exhaust to inlet otherwise.
I always thought it was the other way round?
10-04-2006, 02:11 PM
#11
Professional Waffler
Originally Posted by sibster
EGR on the WRC car is used in conjunction with normal modified ISCV als...we actually use a Focus WRC EGR as the mountune item is shite....vacuum driven affair....the focus is electric/electronic..a very trick valve with a solid state relay controlling it....it basically blows air from the hot side induction pipe (before the intercooler) into the four branches of the exhaust manifold...the mountune item only uses 2 ports....hard to quantify in performance terms it also aids throttle response....and egt's are 800 - 1000 degrees...als and egr on....
HTH
Ian
HTH
Ian
sounds much easyer than the mountune item, btw i didnt think the mountune item is vacuum driven, i thought it would pressure controlled by the use of a few solinoids,, and because there is no pressure to drive the egr valve, there is a storage canister and one valve valve, so when the car is used on boost, the canister charges with a small amount of pressure 
it does look too me like my understanding of the ford wrc egrals system is right,
steve whats the TIP pressure when on light loads? 
10-04-2006, 02:15 PM
#12
Professional Waffler
4) EGR (Exhaust Gas Recirculation)
Here exhaust gas is metered intdo the intake system. This is not as crazy as it sounds! At low rpm, the exhaust gas is full of hydrocarbons and heat, so helps excite the fuel air mix going in resulting in more volume, better burning and increased exhaust gas volume. It must be turned off at peak loads to allow for full cylinder filling. This really requires a non-standard ECU to control properly and because the car would need to MAP sensor operated.
Here exhaust gas is metered intdo the intake system. This is not as crazy as it sounds! At low rpm, the exhaust gas is full of hydrocarbons and heat, so helps excite the fuel air mix going in resulting in more volume, better burning and increased exhaust gas volume. It must be turned off at peak loads to allow for full cylinder filling. This really requires a non-standard ECU to control properly and because the car would need to MAP sensor operated.
10-04-2006, 02:43 PM
#15
Advanced PassionFord User
Sorry Gareth....ive edited to what I actually meant....i was on doing a reply for servos 
The mountune egr uses pressure and 2 solonoids to control the EGR valve.....if I get time i'll post a pic of the focus egr....
The setup consists of an ally mounting plate welded onto the induction pipe...with a cutout and tapped to mount the valve...similar valve body but it has a large solonoid to operate the valve itself....
Pipework extend to a wiggins coupling and onto a manifold with stubs welded into the manifold before the turbo.....
Ian
ive only got a drawing of the plate which holds the valve and welds on the induction pipe....
The mountune egr uses pressure and 2 solonoids to control the EGR valve.....if I get time i'll post a pic of the focus egr....
The setup consists of an ally mounting plate welded onto the induction pipe...with a cutout and tapped to mount the valve...similar valve body but it has a large solonoid to operate the valve itself....
Pipework extend to a wiggins coupling and onto a manifold with stubs welded into the manifold before the turbo.....
Ian
ive only got a drawing of the plate which holds the valve and welds on the induction pipe....
10-04-2006, 02:56 PM
#18
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Whole EGR system is described on "Forced induction performance tuning" by Graham Bell I think, so if anybody has a copy scanned then he could post it.
10-04-2006, 03:09 PM
#20
DEYTUKURJERBS
Thread Starter
Originally Posted by Azrael
Whole EGR system is described on "Forced induction performance tuning" by Graham Bell I think, so if anybody has a copy scanned then he could post it.
10-04-2006, 03:15 PM
#23
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Great thread 
Ian, im coming up this Friday if your bloke can get the bonnet to me and it fits in the back of a saab 900.. then I can bring it up for you
in return to be shown around your wrc escort
Ian, im coming up this Friday if your bloke can get the bonnet to me and it fits in the back of a saab 900.. then I can bring it up for you
in return to be shown around your wrc escort
10-04-2006, 03:19 PM
#25
Advanced PassionFord User
Originally Posted by DaveEscos
Great thread
Ian, im coming up this Friday if your bloke can get the bonnet to me and it fits in the back of a saab 900.. then I can bring it up for you
in return to be shown around your wrc escort
Ian, im coming up this Friday if your bloke can get the bonnet to me and it fits in the back of a saab 900.. then I can bring it up for you
in return to be shown around your wrc escort
if I find it i'll let you know......thanks for the offer....your more than welcome to come for a gander....Ian
11-04-2006, 02:38 PM
#28
Advanced PassionFord User
another way to acheive als is with an actuated throttle, driven by a stepper motor that way you could eliminate the modifed ISCV and allow you to bypass as much air as you like. We are looking at a few options at the moment, idealy something fly by wire but cant perfect it....
11-04-2006, 04:22 PM
#29
Professional Waffler
sibster
thought about this myself,,, but it does get complex, and i got no realy time too look into it
just making a massive bypass is the easyest way
thought about this myself,,, but it does get complex, and i got no realy time too look into it
just making a massive bypass is the easyest way
12-04-2006, 08:50 PM
#33
DEYTUKURJERBS
Thread Starter
Ive seen it on the road (relativley) all the time, and I live about 20miles away
Its just a weekend fun car, but he dont use it much, or hard, but its fucking awesome.
Hes also got a DC5 Integra TypeR and Rover 600turbo tho.
Ive only been in it once in its new spec IIRC, as since ive not had any interesting transport I dont see him much anymore unfortunatley.
Its just a weekend fun car, but he dont use it much, or hard, but its fucking awesome.
Hes also got a DC5 Integra TypeR and Rover 600turbo tho.
Ive only been in it once in its new spec IIRC, as since ive not had any interesting transport I dont see him much anymore unfortunatley.
01-09-2006, 10:28 AM
#34
DEYTUKURJERBS
Thread Starter
Ok, i was just reading this again, and still dont totally get it
EGR air goes from just after compressor outlet, thru a bypass valve, and into the 4 branches of the ehxaust manifold?
So when off throttle the pressure at compressor outlet is always higher than in ehxuast manifold then? Or itd not work?
Does this still leave enough air to bypass throttle for normal ALS to work?
How if the amount of air metered (ie so its not too much that it makes the normal ALS innefective), just by the valve size?
I take it this could run on P8 etc surely as this bypass would only need to be open at same time as normal ALS valve wouldnt it?
Or am I missing a lot here?
EGR air goes from just after compressor outlet, thru a bypass valve, and into the 4 branches of the ehxaust manifold?
So when off throttle the pressure at compressor outlet is always higher than in ehxuast manifold then? Or itd not work?
Does this still leave enough air to bypass throttle for normal ALS to work?
How if the amount of air metered (ie so its not too much that it makes the normal ALS innefective), just by the valve size?
I take it this could run on P8 etc surely as this bypass would only need to be open at same time as normal ALS valve wouldnt it?
Or am I missing a lot here?
01-09-2006, 03:08 PM
#38
Advanced PassionFord User
Originally Posted by Stavros
Ok, i was just reading this again, and still dont totally get it
EGR air goes from just after compressor outlet, thru a bypass valve, and into the 4 branches of the ehxaust manifold?
So when off throttle the pressure at compressor outlet is always higher than in ehxuast manifold then? Or itd not work?
Does this still leave enough air to bypass throttle for normal ALS to work?
How if the amount of air metered (ie so its not too much that it makes the normal ALS innefective), just by the valve size?
I take it this could run on P8 etc surely as this bypass would only need to be open at same time as normal ALS valve wouldnt it?
Or am I missing a lot here?
EGR air goes from just after compressor outlet, thru a bypass valve, and into the 4 branches of the ehxaust manifold?
So when off throttle the pressure at compressor outlet is always higher than in ehxuast manifold then? Or itd not work?
Does this still leave enough air to bypass throttle for normal ALS to work?
How if the amount of air metered (ie so its not too much that it makes the normal ALS innefective), just by the valve size?
I take it this could run on P8 etc surely as this bypass would only need to be open at same time as normal ALS valve wouldnt it?
Or am I missing a lot here?
The description is about spot on pal....there is enough air still being prouduced for the ALS to still work...never seen it used on a P8...we run it on the T6..
It is cycled on its own output...
Example map from the T6 if it helps
Menu : ECU Software Setup
Group : OUTPUT FUNCTIONS ->
Group : EGR VALVE ->
Map : EGR Valve On f(RPM) (RPM)
1000
Menu : ECU Software Setup
Group : OUTPUT FUNCTIONS ->
Group : EGR VALVE ->
Map : EGR Valve Off f(RPM) (RPM)
900
Menu : ECU Software Setup
Group : OUTPUT FUNCTIONS ->
Group : EGR VALVE ->
Map : EGR Valve On f(TPS) (ř)
20
Menu : ECU Software Setup
Group : OUTPUT FUNCTIONS ->
Group : EGR VALVE ->
Map : EGR Valve Off f(TPS) (ř)
21
Menu : ECU Software Setup
Group : OUTPUT FUNCTIONS ->
Group : EGR VALVE ->
Map : EGR Valve Frequency (Hz)
100
Menu : ECU Software Setup
Group : OUTPUT FUNCTIONS ->
Group : EGR VALVE ->
Map : EGR Valve On Duty (%)
100
Menu : ECU Software Setup
Group : OUTPUT FUNCTIONS ->
Group : EGR VALVE ->
Map : EGR Valve Maximum On Time (secs)
8
