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Discussion Starter #1
Hi there! I read about the EGR system and I dont like the idea of putting exhaust gas into the admision. Has anybody got rid of it? I would apreciate so much if somebody could tell me how to do it and if there are any problems related. Thanks in advance
 

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Hi there! I read about the EGR system and I dont like the idea of putting exhaust gas into the admision. Has anybody got rid of it? I would apreciate so much if somebody could tell me how to do it and if there are any problems related. Thanks in advance
I simply blocked the tube, the difference is noticable :thumbs:
 

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Discussion Starter #3
Thanks! I read there could be missfire at high revs, have you noticed any?
 

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Thanks! I read there could be missfire at high revs, have you noticed any?
No, not at all!

I've been told that EGR works only at partial-load - however, after closing it, there's a feeling as if there was better acceleration througout the range.
 

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Discussion Starter #5
Something has to gain for sure, putting in the admision hot burned air directly from the exhaust is the worse thing you can do to a combustion engine. What tube did you block? The one coming from the exhaust?
 

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Something has to gain for sure, putting in the admision hot burned air directly from the exhaust is the worse thing you can do to a combustion engine. What tube did you block? The one coming from the exhaust?
As far as I remember there is only on tube that leads into the valve(?) (ofcourse, should be the one which brings in the worn air from the exhaust-system) - I put a small bolt into the tube (wich was small enough to fit the tube and large enough to block the input of the tube).

I've been told that this EGR-systems are wide-spread among diesel-engines?

KR
 

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Discussion Starter #7
I dont know much about diesel engines but this wikipedia article explains it pretty well

EGR in spark-ignited engines

The exhaust gas, added to the fuel, oxygen, and combustion products, increases the specific heat capacity of the cylinder contents, which lowers the adiabatic flame temperature.

In a typical automotive spark-ignited (SI) engine, 5 to 15 percent of the exhaust gas is routed back to the intake as EGR. The maximum quantity is limited by the requirement of the mixture to sustain a contiguous flame front during the combustion event; excessive EGR in poorly set up applications can cause misfires and partial burns. Although EGR does measurably slow combustion, this can largely be compensated for by advancing spark timing. The impact of EGR on engine efficiency largely depends on the specific engine design, and sometimes leads to a compromise between efficiency and NOx emissions. A properly operating EGR can theoretically increase the efficiency of gasoline engines via several mechanisms:

Reduced throttling losses. The addition of inert exhaust gas into the intake system means that for a given power output, the throttle plate must be opened further, resulting in increased inlet manifold pressure and reduced throttling losses.
Reduced heat rejection. Lowered peak combustion temperatures not only reduces NOx formation, it also reduces the loss of thermal energy to combustion chamber surfaces, leaving more available for conversion to mechanical work during the expansion stroke.
Reduced chemical dissociation. The lower peak temperatures result in more of the released energy remaining as sensible energy near TDC, rather than being bound up (early in the expansion stroke) in the dissociation of combustion products. This effect is minor compared to the first two.

It also decreases the efficiency of gasoline engines via at least one more mechanism:

Reduced specific heat ratio. A lean intake charge has a higher specific heat ratio than an EGR mixture. A reduction of specific heat ratio reduces the amount of energy that can be extracted by the piston.

EGR is typically not employed at high loads because it would reduce peak power output. This is because it reduces the intake charge density. EGR is also omitted at idle (low-speed, zero load) because it would cause unstable combustion, resulting in rough idle. The EGR valve also cools the exhaust valves and makes them last far longer (a very important benefit under light cruise conditions)[citation needed]

Since the EGR system recirculates a portion of exhaust gases, over time the valve can become clogged with carbon deposits that prevent it from operating properly. Clogged EGR valves can sometimes be cleaned, but replacement is necessary if the valve is faulty.

In diesel engines

By feeding the lower oxygen exhaust gas into the intake, diesel EGR systems lower combustion temperature, reducing emissions of nitrous oxides. This makes combustion less efficient, compromising economy and power. Diesel EGR also increases soot production
, though this was mitigated in the US by the simultaneous introduction of diesel particulate filters.[6] EGR systems can also add abrasive contaminants and increase engine oil acidity, which in turn can reduce engine longevity.

So basically the only benefit, apart from less NOx pollution, is lower temperatures inside the combustion chamber which increases components life. Sounds like direct loss of power at some regimes.

I also understood that diesel engines needed it before particles filters appeared so they would pass NOx regulations.
 

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Hi Colo, did you ever block your EGR valve in your GTV? Did errors appear? How was performance? Did you alter the ecu coding or not?
 

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Discussion Starter #9
I did! I've had it blocked for years. I didn-t touch the ECU, and I never check for errors. I remember that I noticed that the car was running better, but probably just a very small gain. I mostly did it because I dont like the idea of putting dirty smoke back into the engine. I also replaced the pipe that puts oil vapour from the engine into the flexi pipe with a small filter.
 

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I did! I've had it blocked for years. I didn-t touch the ECU, and I never check for errors. I remember that I noticed that the car was running better, but probably just a very small gain. I mostly did it because I dont like the idea of putting dirty smoke back into the engine. I also replaced the pipe that puts oil vapour from the engine into the flexi pipe with a small filter.



Hi Colo, any chance of some pics of your set up please ?

Thanks
 

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Thank you for your reply Colo. In your photographs i see that your car is a phase 1 GTV.
My GTV is phase 2 which runs on a different ecu(ME2.1). I wonder if disconnecting the EGR on the phase 2 will create errors and problems for the engine?
Anyone else who has tried this on a phase 2 is welcome to respond.
Thank you.
 

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EGR on a busso V6? Really? Never heard of it.. :paranoid: i thought EGR is only used in modern diesel engines?
 

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I think it's just a bit of a mix up with terminology.. oil vapours are piped back into the intake, there's no EGR (exhaust gas recirculation) on the GTV V6.
 

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EGR on a busso V6? Really? Never heard of it.. :paranoid: i thought EGR is only used in modern diesel engines?
Some Petrol engines used to use EGR, ie very early CF1 16v TS.
Don't think the V6 ever had it.
 

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If you do what Colo did and place a blanking plate between egr valve and manifold and leave everthing connected that will be fine. The ECU won't know it's been blocked off. If you have a laptop and software you could unplug the lead to the egr solenoid to see if it brings on the eml and reset it if it does.
 

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If you do what Colo did and place a blanking plate between egr valve and manifold and leave everthing connected that will be fine. The ECU won't know it's been blocked off. If you have a laptop and software you could unplug the lead to the egr solenoid to see if it brings on the eml and reset it if it does.
Thank you Spankdanny for explaining that. I would just like to clarify that Colo's is a phase 1 and mine is a phase 2. So euro 2 as opposed to euro 3 ecu system. I am assuming that the phase 2 has more complicated software( checks and balances) for emissions. Just blanking of the valve has worked for Colo's phase 1. Do you think that it would work for a phase 2? I do not have that software either to alter the ecu.
 

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There is EGR on the GTV v6. See attached workshop manual.
I stand corrected! I remember seeing some extra bits on the press photos for the GTV v6 when it first came out - always wondered what it was. So the early v6 must have EGR, interesting.
 
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