smittyb said:
+1
Did you block the EGR ports at the heads where the meet the lower intake? If not, your EGR is still functional somewhat. You may run rich at part throttle settings by taking the vacuum line off to keep it from injecting the inert air into the engine. I would put the vac line back. There is nothing to gain by removing it
I ran with no EGR for about a year, cause the intakes egr passage was broken, and had issues with pinging and couldn't advance my timing past the stock 10*. Never had any issues with poor idle or any other drivability issues other than the inability to advance timing.
Personally I would reconnect the vacuum hose and keep the EGR. The "EGR hurts perfomance" belief originated with the early EGR systems, which did hurt perfornace, but the performance problems have been resolved. It actually improves performance by allowing you to advance you timing, reducing emissions and providing better gas milage, so in the end it is best to keep it. If you decide that you don't want to keep it the best thing to do is have it turned off with a tune. That way the computer will know that and be able to compensate for the increase amount of air and it won't lean out.
Personally I would reconnect the vacuum hose and keep the EGR. The "EGR hurts perfomance" belief originated with the early EGR systems, which did hurt perfornace, but the performance problems have been resolved. It actually improves performance by allowing you to advance you timing, reducing emissions and providing better gas milage, so in the end it is best to keep it. If you decide that you don't want to keep it the best thing to do is have it turned off with a tune. That way the computer will know that and be able to compensate for the increase amount of air and it won't lean out.
mob said:
Yup, the EEC thinks the inert gas injected by the EGR at part throttle is still present. SInce inert air doesn't burn, the computer doesn't need to add fuel for that portion of air.
WHen you disable the EGR, the EEC is still pulling fuel out for the inert air that SHOULD be there. SInce that air is now replaced by air that can burn, the lesser fuel will cause you to run slightly lean. You may get detonation and other troubles at part throttle settings.
A computer tune will read this and can compensate by adding slightly more fuel. Only way i would remove the EGR is if i was planning on getting a custom tune anyway. They you will be safe.
Quote:
Exhaust gas is routed back into the combustion chamber because the exhausted air is much hotter than the intake air (try touching a muffler sometime). By sending warmer gas into the combustion chamber, the air/fuel mix does not have to do as much work to heat up, and your engine runs more efficiently.
Not exactly. It has little to do with the temperature of the exhaust gas (although I am sure that is a factor).
The major reason for the use of EGR is that the exhaust gasses are inert. In other words there is very little oxygen in the exhaust gas.
This is what Mustang5L5 is getting at above.
The heat of the exhaust gas is a secondary benefit. The primary reason for using the exhaust gas is because of the lack of oxygen.
jason
Exhaust gas is routed back into the combustion chamber because the exhausted air is much hotter than the intake air (try touching a muffler sometime). By sending warmer gas into the combustion chamber, the air/fuel mix does not have to do as much work to heat up, and your engine runs more efficiently.
Not exactly. It has little to do with the temperature of the exhaust gas (although I am sure that is a factor).
The major reason for the use of EGR is that the exhaust gasses are inert. In other words there is very little oxygen in the exhaust gas.
This is what Mustang5L5 is getting at above.
The heat of the exhaust gas is a secondary benefit. The primary reason for using the exhaust gas is because of the lack of oxygen.
jason
It does have to do with exhaust gas temp also. NOx molecules are more readily formed below a certain temp. By reintroducing hot exh gasses, the combustion chamber temp is raised above that temp. I want to say it something like 1200 degrres, but that sounds too hot when I THINK ABOUT IT. But then again, thinking hurts my head.
i deleted mine and the only problem i ended up with was a check engine light.solved the problem with a egr delete
piece i bought on ebay for 25.00.contrary to popular belief if you buy the ford electronics manual it will tell you that the egr only operates at full throttle anyway.it does nothing in regular driving conditions. i have had no troubles with timing or other wise.i do have a lifter pecking,but that has nothing to do with the egr.its been pecking for about 5000 miles.
piece i bought on ebay for 25.00.contrary to popular belief if you buy the ford electronics manual it will tell you that the egr only operates at full throttle anyway.it does nothing in regular driving conditions. i have had no troubles with timing or other wise.i do have a lifter pecking,but that has nothing to do with the egr.its been pecking for about 5000 miles.
smittyb said:
actually its exactly the opposite, the exhaust gas cools the combustion chambers, because it will not burn it just takes up space so theres less room for fuel and air, thus lowering combustion chamber temps, NOx occours at higher combustion temps
also one of the problems you can run into without a EGR is detonation
fiveohjunkie said:
All this does is turn off the Check Engine Light.
These plugs do not turn off the egr function in the EEC, so all the part throttle detonation problems can still occur.
I have used these plugs and they seem to work, as my CEL never came on while it was plugged in.
I should have sprung for the tweecer sooner though, and taken care of the problem the correct way.
jason
jeremey thomas said:
I would like to see a quote from the Ford manual that says this.
This is completely contrary to every document I have read on the EGR.
Which includes countless papers published by SAE.
As well as 4 textbooks publishes by SAE.
Also, all of the documentation I have found on the internet is contary your statement of the EGR only functioning at WOT.
Please provide the full name of the text, and publisher name. I would like to read the book myself.
EGR should not be functioning at WOT, as there are very few emissions requirements to meet at WOT.
jason
smittyb said:
You have the right idea, just things are reversed.
The hotter the combustion temps the more NOx will be produced.
As stated in previous posts...
The exhaust gas is inert and displaces Oxygen in the intake charge. The reduction of Oxygen reduces the peak temp of the flame front. The lower combustion temps reduce the formation of NOx.
The exhaust gasses are supposed to be cooled to a reasonable level before being introduced to the fuel. This is the purpose of the coolant in the EGR spacer.
Full temp exhaust gasses could cause pre-ignition at part throttle.
jason
Dear Stangnet User,
There is no problem with taking off your EGR. MyBad70's has been off since last year, and I recently deleted mine by way of an Accufab 70mm TB with a blank spacer and the $30 plug in to keep the Check Engine light off. You really have little to gain however, if you do not buy an intake that doesn't use egr. Your stock intake and some others have a hole where they connect upper to lower, so it is still "working" technically. If you weld that hole up I've heard it's worth 5 hp depending on your set up. If it works properly and you have the stock intake I'd say just keep it
Thanks,
Dr. Strype
There is no problem with taking off your EGR. MyBad70's has been off since last year, and I recently deleted mine by way of an Accufab 70mm TB with a blank spacer and the $30 plug in to keep the Check Engine light off. You really have little to gain however, if you do not buy an intake that doesn't use egr. Your stock intake and some others have a hole where they connect upper to lower, so it is still "working" technically. If you weld that hole up I've heard it's worth 5 hp depending on your set up. If it works properly and you have the stock intake I'd say just keep it
Thanks,
Dr. Strype
This is a great post . very informative . One of the things I love about stangnet . Theres some smart fellers on here!
I will be deleting my EGR soon when I do my H/C/I because I got a nice deal on an 99 Explorer intake which does not have provisions for egr . I became concerned while reading this post because of that dreaded word "DETONATION" . From what I understand that is not a good thing when running nitrous which are included in my future plans . These detonation issues were happening only at part throttle and not at WOT where the EGR is not functional anyway......? Right? So it would be safe to run NX with a WOT activation switch and not have issues with detonation . Am I correct in assuming this?
I will be deleting my EGR soon when I do my H/C/I because I got a nice deal on an 99 Explorer intake which does not have provisions for egr . I became concerned while reading this post because of that dreaded word "DETONATION" . From what I understand that is not a good thing when running nitrous which are included in my future plans . These detonation issues were happening only at part throttle and not at WOT where the EGR is not functional anyway......? Right? So it would be safe to run NX with a WOT activation switch and not have issues with detonation . Am I correct in assuming this?