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Originally posted by Hdbngr8:
The simple reason is that race car engines typically aren't built with emissions in mind. There is no benefit using EGR other the emissions - unless the engine was designed with EGR in mind. Then you would have to consider that it may not have been designed with higher cylinder temperatures in mind. Higher temperatures can create problems with the piston, head, and cylinder wall. By running lower cylinder temperatures the designer may have gotten away with a piston design that may melt down under higher temperatures. Best be careful when playing around with this.
Bogus ... the stock 3L pistons have proven via many that it can sustain quite a bit of boost ... no way in hell that the EGR is lowering temps that would otherwise be higher NA than pushing 12psi through a turbo.
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I have no life
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I have no life
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EGR = added octane= slower burn of fuel and resistance to detonation. Slower burn (slower/lower rise in cyl gas temps/pressures) reduces NoX(very high compression ratios give high NoX)...Egr does NOT operate below optimum engine operating temps and not all the time. In most calibrations it operates on steady cruise driving and on overrun conditions. Down side of EGR delete 'can' be pinging so an ignition retard (loss of power) may be required with no EGR.
-'96 SE MTX 3L
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No, it's not bogus. My statement was more of a general one and not necessarily aimed at the 3.0 Duratech. I am in agreement with you that there is no real benefit to using EGR other than emissions (hence why the racing world does not use them). Because of the numerous 3L turbo engines out there it would appear that the stock pistons are likely stout enough to deal with the higher temps. All I am saying is you need to do your homework before you run off and block the EGR.
'98 SVT Red/midnight blue - a few mods
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Hard-core CEG\'er
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Originally posted by todras:
EGR = added octane= slower burn of fuel and resistance to detonation. Slower burn (slower/lower rise in cyl gas temps/pressures) reduces NoX(very high compression ratios give high NoX)...Egr does NOT operate below optimum engine operating temps and not all the time. In most calibrations it operates on steady cruise driving and on overrun conditions. Down side of EGR delete 'can' be pinging so an ignition retard (loss of power) may be required with no EGR.
If the EGR does NOT operate below optimum engine operting temps, then wouldn't that mean that "it helps the car warm quicker" is a false assumption? This is what I'm talking about ... seriously conflicting information out there on the subject. Prior to the clean air act of 1970, nobody knew what and EGR was ... it didn't exist ... it's the brainchild of someone looking to pass an emissions test. Don't get me wrong, I'm all for keeping it on the car and all other emissions control devices, but let's not jump on the bandwagon with false information here. I say this even though I too live in an area that doesn't require emissions testing. I'm not playing devil's advocate on this subject, I just want to know the REAL benefits of having/not having an EGR system on the car, and not some automotive myths/assumptions.
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EGR's sole function is to reduce combustion temperatures in order to reduce the formation of NOx. There is no performance benefit; in fact it is detrimental to engine performance. It is there so that engines can pass EPA emissions standards only. The only caveat is higher combustion temperatures MAY cause durability problems IF the engine was not specifically designed without EGR - this does not mean every EGR engine WILL have problems w/o it. There is some potential risk by removing it; the risk has to be evaluated for a particular engine. If you want to know more, PM me, and I will talk to my companies engine designers across the street from me.
'98 SVT Red/midnight blue - a few mods
E0 wheels for sale - PM me
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WEll, we do know that it isn't functional at WOT but it IS functional at cruise and a few other times.
The highest cylinder temps are when you run lean as in a lean burn cruise A/F ratio to save gas, deceleration initially as all the fuel is burning out, and of course if you run lean mixtures at WOT it will get really HOT.
But the engine uses fuel to keep combustion temps down under WOT, so I don't know about the EGR protecting the car at WOT.
I know DemonSVT studied the PCM controll of the EGR and can shed better light on when it is actually uses.
From what I gather it makes no impact on performance though.
Former owner of '99 CSVT - Silver #222/2760
356/334 wHP/TQ at 10psi on pump gas!
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EGR and what it really does:
egr recycles waste exhaust gas puts it back into the cylinders (as much as 10% of the total air intake of the engine on some engines) its NOT used to "reburn" unburned gasses. its used to take up space in the cylinders thus using less fuel. it also cools down the cyl temps to reduce NOx emissions. EGR does not function at WOT. it doesnt help performance at all. it DOES increase gas milage and reduce emissions. thats all its designed to do. but what do i know....im in class now and taking the test for my PA emissions license feb 1st.....
Russell
Oval Port 3L Nearly Done
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Originally posted by Blackcoog:
I also heard that it is used to heat up an engine quicker on cold days. Is there any truth to that? I could see how someone could beleive that since the exhaust gas is filtered back into the intake.
A no.
The EGR isn't active until the engine is warmed up.
Jim Johnson
98 SVT
03 Escape Limited
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Originally posted by Russell-3L:
EGR and what it really does:
egr recycles waste exhaust gas puts it back into the cylinders (as much as 10% of the total air intake of the engine on some engines) its NOT used to "reburn" unburned gasses. its used to take up space in the cylinders thus using less fuel. it also cools down the cyl temps to reduce NOx emissions. EGR does not function at WOT. it doesnt help performance at all. it DOES increase gas milage and reduce emissions. thats all its designed to do. but what do i know....im in class now and taking the test for my PA emissions license feb 1st.....
Although mostly correct, there is one error in what they are teaching you. EGR does NOT improve fuel economy. I used to teach this stuff for for people getting their smog license.
EGR lowers peak combustion temperature. Basically because it has already been through the combustion chamber, it is just inert filler. It is about like injecting an inert gas instead, such as pure nitrogen, argon, or any of the gasses used to keep the metal from reacting with oxygen in mig welding.
EGR does not "lean out the mixture". Instead, it just adds fluff, something that can't burn.
Once EGR is introduced into the equation, fuel curve and ignition timing can be somewhat optimized for the less than ideal situation. If done properly, little if any drivability issues are generated. If not done properly, power will be worse than it could be, there can be engine hesitations, engine surges as the EGR is introduced, and there can be "chuggle" or "trailer hitching".
If the timing and fuel curves have been designed (or set by the factory) for EGR, then again, they must be altered to keep from having engine ping or fuel mixture problems.
Jim Johnson
98 SVT
03 Escape Limited
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