Discussion in 'Need for Speed!' started by Turdle, February 26, 2008.
Here we go guys--
Read please-then post.
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I knew what an EGR was but didn't know what its actual purpose was until I read that and I think its good because it lowers emissions. I'm not looking for a car to perform perfectly and there has to be some give and take. Give cleaner air, take a little performance (assuming an engine with no egr at all performs significantly better).
But even if we decide that we don't like the idea of EGR that there isn't much we can do about because its already built into the computer and the engine.
Removing the EGR won't increase power and has the potential to lower fuel economy when removed. As far as a performance gain for removal there isn't any to be had. Actually removing the EGR lowers the detonation threshold.-j
^^^What he said^^^
EGR = good, if you're truck has it, it'll only help your MPG/performance
*From a graduate mechanical engineering student working at Colorado State Engines & Energy Conversion laboratory that performs all sorts of engines/emissions/power research*
I also understand EGR will increase life of the compression rings.
Ever notice how pre- egr cars were worn out at 100k miles?
I had always thought removing the EGR improved power, guess not though. Good stuff to know.
Back in the day of carburated cars removing the EGR did gain power, there were big freaking tubes that ran through the intake and bogged down stuff. That and they were huge and took up alot of room. The only thing worse were those enormous smog pumps with huge hoses and tubes that always ended up breaking and just took up tons of room. None of which were hooked up to a computer... cause there was no "computer" to be had. So most of the old hot rod guys would take all of it off along with the AC and gain alot of power, and buying a new intake manifold took car of the egr.
Now a days its smaller and placed all nicely and help aid performance, thanks to the computer.
Interesting read. I never actually knew what the purpose of the system was.
My EGR system is not functioning right now and I can tell you I have DEFINITELY seen a loss in fuel economy. Ouch. lol
I had thought EGR may also aid in warming up a very cold engine on a winter day. It seems like it would, but the article said EGR doesn't function at idle, so that tells me no.
Yes, there are many articles out there that describe this same thing. This article is one of the best I've seen so far - Good find!
I hope the guys that argue removing the EGR is a good thing read this.
Bringing this up to say it should be stickied somewhere, I have been looking for that article in the first post for a little time now.
i like what he said in that article and i agree with it but do have one thing that somewhat contradicts egr being good for preformance. When you are running the exhaust gas back into your intake it dilutes the amount of air and fuel that can go into your cylinders. the less air and fuel that can be pumped threw and engine the less power it will have. One more thing is that in the end of his article he says that because your engine knocks it loses power? An engine will still knock with egr. It was explained to me that an engine advances timing untill it knocks and then backs off timing from there. I am not sure on the knock and backing off timing but i know that egr does indeed dilute your air/fuel mixture. There still is preformance gains from an egr though.
I think egr has is benefits but the comparison was made only with a computer thinking it had egr not to vehicle tuned to forget that egr ever existed. So I think that msilver made a good point. Given the same engine one egr tuned, and the completely without egr or tuning for it which could make the better power?
Either Both would make the same, or the one with the EGR would be on top. Not to mention the engine with the functioning EGR would get way better gas mileage.
The main difference with tuning would be the one with the EGR could run more timing, which usually results in better performance.
EDIT - Just noticed msilver response.
In my own words --
The air is replaced with exhaust that will not burn again. Because of this, and when introduced back into the combustion chamber, (replaces a small amount of incoming air) the combustion chamber temp is lowered. Because of this new lower temp, more timing can be run. And because more timing can be run, more performance and better gas mileage is achieved. This new lower temp, more timing combination USUALLY offsets the more air, more gas combination.
So my vote is for the engine running an EGR valve.
Adding EGR gas to the cylinder may cool it down and allow the engine to advance the timing, but you also have replaced air/fuel mix with non combustable gas which reduces power. What you are saying is: optimal air/fuel mix will not net more power than the increase in timing will provide. Mind you I am speaking about having the EEC programmed to not use an EGR. I seriously doubt an EGR enabled engine is going to ever outperform an EGR disabled EEC reprogrammed engine.
Better fuel economy is due to the fact that the space the EGR gas will take up means less air gets into the cylinder, which means less fuel is added. Surprise! Reducing air/fuel ratio increases gas mileage. You are basically reducing your displacement (to oversimplify it).
We could also get into thermodynamics, and the efficiency of cooling the cylinder with an exhaust gas...
However, getting your EEC reprogramed for no EGR costs money. Not to mention I don't think the EGR is open at Wide Open Throttle, so who really cares?
also on us fords the dpfe sensor its almost always the faulty one when ever you get thecode of not enough flow. if you dnt want to just throw parts at it check the sensor with a voltmeter i dnt think is a recall but it does mest up i changed mine and instantly saved3 mpg and have no more engine pinging my.02
How true. I always attributed this to better metals and
oils nowdays, but the EGR cooling down the combustion
temps makes sense.
The California Smog technician said I didn't pass the function test event though I passed the pollution test better than 85% of California cars. He said the function test failed because of a faulty EGR valve. I'm getting a new one.
My D900 OBD ll read misfire on cylinder 1. Each time I pulled a different spark plug wire out of the coil module the OBD ll read misfire on cylinder 3. Go figure. I'm supposed to expect replacing the EGR valve will cure all that.
Thoughts of EGR and Direct Injection and issues with carbon build-up?
It's really the pcv juices and egr together that gums up the direct injection motors. Pcvs and crankcase breathers no matter how good they are functioning will get oil in the intake at high rpm in almost every vehicle. Just idi motors don't have the fuel injectors washing down the intake valve.
Replacing the EGR was a waste. There was an intermittent pinhole in the cylinder 1 spark plug wire. With the new wire the engine ran much better and that eliminated what had seemed to me to be a clicking for the last 7 years coming from one of the timing chains. Then replacing the intake manifold gaskets erased all DTCs and now the SUV runs better than ever. Thanks to any one who gives correct advice, especially StreetRod. That excludes my smog test man.