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exhaust gas recirculation system EGR


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It's not suppost to be open during high loading conditions. It would most definately rob you of power then. It is only suppost to open during cruise. Engineers made it that way so that you wouldn't lose power and the fact that, that is the place where the engine spends most of it's time making nox anyway. So if the are calling it high load as in when you go to WOT then I would say that is inaccurate info that any smog tech should be able to shoot down as a lie. Light to medium loads under "1/4 throttle" in most cases is when the EGR is suppost to open.

 

I've talked with numerous smog technicians and the teachers that trained them. In fact I have a 1998 edition of their text book. This is what I was taught. You better have better proof than a google quote, cause that looks faulty to me.

 

I don't deny that what your saying is sound, but I will say that at the time which I specified the power loss is moot. You'll never know and it doesn't rob you of mileage. All performance aspects are there. Your not racing your car at less than 1/4 throttle and are you?

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The answer to "Does EGR hurt performance?" can be answered with another question "Is part-throttle performance considered Performance?" To some, yes, to some, no. What we can all agree on is that EGR does not HELP performance. On the other hand EGR is said to improve efficiency according to this http://en.wikipedia.org/wiki/EGR

 

Is efficiency = performance? That is an entirely different question...

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You say PO-TATE-O and I say PO-TAHT-O...

 

If one wants to argue what constitues performance:

 

What kind of performance do you get in regard to gas mileage"

 

How does your engine perform in regard to emissions?

 

If you want to measure performance by "area under the curve", then you still are only talking about WOT, and EGR is not an issue.

 

If your definition of performance is to maximize power at all rpm/vacuum conditions, then indeed, EGR affects performance. On a road-race or autoX car, I can see this rather limited view of the word performance applied to good use.

 

On a street car, I think the broader view of all around performance is more appropriate.

 

Semantics.

 

It is documented that you get better mileage and lower emissions on engines with EGR and fuel injection that have been tuned for it.

 

I personally am fond of breathing, and even after I don't have to be emissions tested, I will keep my catalytic converter, MS my ZXT, and utilize a wideband and EGR for my daily driver to maximize performance in the areas of, power, mileage and emissions. No doubt I will bias toward power and mileage (since everything is a compromise something has to take back seat), but I have no doubt that what I end up with will pollute less than the stock EFI system.

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You say PO-TATE-O and I say PO-TAHT-O...

 

If one wants to argue what constitues performance:

 

What kind of performance do you get in regard to gas mileage"

 

How does your engine perform in regard to emissions?

 

If you want to measure performance by "area under the curve"' date=' then you still are only talking about WOT, and EGR is not an issue.

 

If your definition of performance is to maximize power at all rpm/vacuum conditions, then indeed, EGR affects performance. On a road-race or autoX car, I can see this rather limited view of the word performance applied to good use.

 

On a street car, I think the broader view of all around performance is more appropriate.

 

Semantics.

 

It is documented that you get better mileage and lower emissions on engines with EGR and fuel injection that have been tuned for it.

 

I personally am fond of breathing, and even after I don't have to be emissions tested, I will keep my catalytic converter, MS my ZXT, and utilize a wideband and EGR for my daily driver to maximize performance in the areas of, power, mileage and emissions. No doubt I will bias toward power and mileage (since everything is a compromise something has to take back seat), but I have no doubt that what I end up with will pollute less than the stock EFI system.[/quote']

..

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  • 3 months later...

I guess the main question, wojo, is what do you expect to gain by removing it?

 

That will determine if the time and expense expended by deleting it is worth it.

 

If you have a stock ECU (er, calibrated to take the EGR into account), & Stock Intake, I would say "NO, leave it on, it's not hurting anything"...

 

Now, if you have a recalibrated EFI system from Europe ready to supplant it, then yeah, pick up the 20 extra HP the Eurospec Turbos have, but you also need the .82AR exhaust housing, to remove the cat, the pneumatic retard distributor, and all associated blockoff plates for the EGR and the AAC...

 

Thinking you don't have any of those....

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I'd consider EGR a performance hurting system. I've driven cars with and without (disabled, same motor) and you definitely notice a difference. The difference is in fact in partial throttle situations, typically taking off from a stop. I believe the spec is 2,000-3,000 RPM. The big annoying thing about EGR is that when it malfunctions (e.g. carbon clogging), it causes serious drivability issues, namely low RPM bucking.

 

The flipside is of course a huge decrease in NOx. It also seems to decrease HC, probably because youre burning off some left over fuel from the exhaust stream that gets recirculated. But it's primary purpose is NOx.

 

Do I think the decrease in NOx is worth the small decrease in performance and increase in maintenance? Sure, everyone likes to breathe cleaner air. Would I add EGR if I could pass emissions without it? Probably not.

 

 

- Greg -

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"The big annoying thing about EGR is that when it malfunctions (e.g. carbon clogging), it causes serious drivability issues, namely low RPM bucking."

 

So that would be a "No Vote" in my book, as by blocking the plates, you should simulate the exact same thing as a plugged EGR Riser...

 

Hence my allusion to the "Stock ECU Calibrated for the EGR"

 

To decrease NOx without EGR, all other things being equal, run 15%+ ethanol. It drastically decreases the NOx content of the tailpipe gasses, but also decreases fuel mileage...

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  • 2 years later...

I know this is old but I thought Id mention some useful info...

 

Im not sure as to how it affects "performance" or "efficiency" when operating properly, but I think it is having a negative effect on most of our 30+ year old cars. If you take the time to cut off the rear egr port and see whats inside youll know what Im talking about. Ive cut several off and as soon as its cut off I have a nice pile of carbon powder/chunks on the workbench. Alot of it. My best bet is alot of this doesnt just sit in the egr rail its whole life. Even though the egr valve is closed while your cruising or at partial throttle, I think all of that junk is still going into the engine.

 

So im guessing this obviously has an affect on combustion but wont it also affect the life expectancy of your valves or even your turbo.

 

Also, Tony are the Euro components mostly transferable? Seems like they got the good stuff. :)

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