Whats the EGR valve For???

[Hissss5]

Sorry... wrong year thread,but pretty much most of there mustangs have a EGR valve....This may sound dumb, but im going for it. On a 95 cobra 5.0 will the car keep trying to stalling at idle ( up and down rpms) without a EGR valve. I just got the car two weeks ago and the guy i got it from took the whole egr assy out..(everything that the egr needs to work)....and he has the smog paper work since 3/16/2010..with the check engin light on

If he didnt need the egr valve how did he drive it around town without any issues.....and pass smog

 

[zPipes]

buddy at emissions testing?

 

[st4ng07]

The egr pretty much takes inert gases from the exhaust and puts them back in to the combustion chamber. It helps with emissions and it lowers combustion chamber temps. Their is really no benefit of taking it off.

 

[zPipes]

well if they werent combusted the first time, wouldnt that mean that they are, in essence, less than optimal gasses - therefore reducing the purity, of the air in the chamber? maybe lowering octane a bit or something, or just getting less compression from the combustible gasses?

ok ok most of that was just random thinking from my brain, it sounds like logically that could make sense, but please chime in and give me a more experienced/knowledged answer. thanks!

 

[99Cobra_vert]

The EGR valve, under certain circumstances, redirects unburned exhaust back into the engine. This reduces emissions and also increases gas mileage and driveability, and even prolongs engine life. The gases sent back to the engine is small (5-20%); anything more will cause problems such as preignition and other anomalies.

The EGR is a good thing. Why people remove it is beyond me since it doesn't work at full throttle anyway. The computer doesn't let the EGR valve open at WOT.

 

[Hissss5]

would it make the car idle like crap?

 

[zPipes]

Interesting information. Thanks for the input.

 

[99Cobra_vert]

would it make the car idle like crap?

If it is removed and the computer does not know it, definitely. The computer compensates for EGR flow by adjusting timing and fuel rates.

 

[GreySVTSnake01]

If it is removed and the computer does not know it, definitely. The computer compensates for EGR flow by adjusting timing and fuel rates.

You shouldn't keep secerts from your ECU.

 

[Jimmysidecarr]

The EGR recirculates a small amount of exhaust gas.
The gas functions as a combustion damper and keeps the combustion temps below the point where Nitrogen from the air fuel mixture combines with Oxygen.
This keeps NOX levels down in the exhaust.

It also helps keep detonation suppressed and allows for more aggressive timing advance. Not exactly sure how this last function exactly works but I suspect it is from the lower combustion temps.

On many new engines the EGR has been eliminated by variable independent cam timing, where overlap can provide the tiny amount of exhaust needed to keep the combustion temps below the NOX threshold.

That's my understanding anyway.:shrug::beer:

 

[zPipes]

** New and Updated Information **


Gotta love us Florida boys. My buddy says, and i quote "if it was such a good thing, then why arent they on the NASCAR cars."

Now thats some good southern logic right there.

 

[Adam01Snake]

** New and Updated Information **


Gotta love us Florida boys. My buddy says, and i quote "if it was such a good thing, then why arent they on the NASCAR cars."

Now thats some good southern logic right there.

Finally....Someone said something that I could understand! :banana:

HAHA!

Good stuff!

-Adam

 

[birdman941]

well if they werent combusted the first time, wouldnt that mean that they are, in essence, less than optimal gasses - therefore reducing the purity, of the air in the chamber? maybe lowering octane a bit or something, or just getting less compression from the combustible gasses?

ok ok most of that was just random thinking from my brain, it sounds like logically that could make sense, but please chime in and give me a more experienced/knowledged answer. thanks!

Using EGR reduces the oxides of nitrogen at the tailpipe.
Cooler combustion temps also let you run more timing.
If it didn't work, the automakers would not be using it since the 70's.

 

[zPipes]

Well, I pretty much agree with my buddy's logic. If it was all that great why dont NASCAR cars use them. Also.. why do cars run just fine w/o them. It appears to be quite controversial and unclear whether or not its really all that important. Hell cars come with Catalytic Converters too... but most of us yank em off anyhow.

Also, if this mod would require the removal of the EGR Valve, and it wasnt worth the gains, I would think that less people would be doing it. There was that one chart that showed the gains of the spacer, but I think that was with the EGR still attached I'm not sure.

 

[cobraracer46]

Well, I pretty much agree with my buddy's logic. If it was all that great why dont NASCAR cars use them. Also.. why do cars run just fine w/o them. It appears to be quite controversial and unclear whether or not its really all that important. Hell cars come with Catalytic Converters too... but most of us yank em off anyhow.

The propose of the EGR valve is to inject an inert gas(exhaust gas) into the combustion chamber during light cruse part throttle operation to keep the air charge temp below 2500 degrees. Keeping the combustion chamber temp below 2500 degrees during cruising conditions keeps NOX emissions down.

The EGR system does not work at idle or wide open throttle and the car could ping at part throttle if it is not working.

Knowing this, it is a total waste of time to remove the EGR system since the EGR does not operate at wide open throttle.

 

[zPipes]

So can we find a mod to extend this tube or hose deal that is causing the need for removal on larger type spacers? Has anyone found a way to do this w/o completely removing it? Post up a write up if you have, even pics if possible.

 

[M.P. Cobra Fan]

You could possibly get some flew hose and add it to the metal tube. Just a thought.