djmarch

iTrader: (4)

Maybe a stupid question for you expert 3rd gen techs, but what does one pick up, Pros/cons, advantages doing an EGR delete ?

Thanks in advance

UltRoadWarrior9

Do you know what the function of an EGR is?

djmarch

iTrader: (4)

Exhaust Gas Recirculation.......If you're so smart, tell my why people are doing it ?

AlkyIROC

It's an emission device. Lets leave it at that.

My race car, Harley and diesel pickup truck do not have and EGR and they all run just fine.

Wife'sCar

iTrader: (1)

You need a block off plate, plug off the vac lines that went to the solenoids, and have the computer tuned to not look for it and run properly without it. The tune is the most important part. If you block and cap off everything without the tune chances are the car will run like crap. If it's working you are better off keeping it. People mostly delete the system when the valve or solenoid start failing and instead of figuring it out they just get rid of it, there are other reasons as well, but that's most common. A properly running egr system is not losing any power or performance.

It's just not necessary on race cars, being as race cars aren't required to meet epa regulations.

What it does is cause the car to burn any extra unburnt gas to lower any harmful emissions. (That's a very basic description mind you)

UltRoadWarrior9

No. you're defining the function of the catalytic converter.

Wife'sCar

iTrader: (1)

You do realize the Mason Dixon line was between MD and PA and that the capital of the Confederate south was in VA right? Guy asked a legit question. At least he didn't rip everything off then ask how to fix it.

Also for your information most of VA does not have smog checks.

Wife'sCar

iTrader: (1)

And unburnt gas can kill a cat. The "catalytic" converter is a "catalyst" to chemically reduce emissions. It's a big metallic filter.

But you are correct, I was mistaken on the egr function. I do know it supposedly helps keep engine temps lower

Wife'sCar

iTrader: (1)

A car that is built to be raced as in a non street legal, bracket, autocross, time trial, rally, circle, dirt, etc........ that will not be registered for street use. If it's going to be inspected and driven to the track then by that definition it is a street car. Not a race car. I'm sure you knew what I meant.

UltRoadWarrior9

Yup I knew what you meant... My question is, are you trying to help the OP by telling him how to delete his EGR, which will most likely be needed on a street car in order to pass a state inspection. In which case you're not doing the n00b OP any favors are you? Maybe I missed where the OP said he was converting his car to off road use.

Wife'sCar

iTrader: (1)

He asked a question, I answered a question. No one is breaking any laws, it's not up to me to hold his hand and make sure he follows all the rules laws and rules. He's a big boy.

What's not needed is immediately attacking him with things irrelevant to the question. He asked why do people delete the system and what the pros and cons are of doing so. You immediately jumped on him and attacked him because of where he lives, which is the same state I live in I might add. That was uncalled for.

Wife'sCar

iTrader: (1)

Freedom of speech should not be used as an excuse to verbally attack someone.

If you disagree with removing a part then use your freedom of speech to tell him why. List what it does then list why it's a good idea to keep it.

He asked why people delete it, and the pros and cons of doing so. So clearly (no offense to the OP) he's not sure what it does. That's why he's asking. To learn.

You jumped to asking what I would assume was a rhetorical question trying to make him feel bad, then commenced to cussing.

Give him facts not f**ks.

Wife'sCar

iTrader: (1)

There's no need to insult people as much as you have. Why do you feel it's okay to answer a question with making someone feel less intelligent.

Freedom of speech does not apply to the Internet as that freedom is limited to a specific country, this site is international.

Calling me a mommas boy over the Internet make you feel like a big man I hope?

five7kid

iTrader: (14)

Just so you know, I deleted the posts with the insults. Fair warning, insulting TGO members is not tolerated on thirdgen.org. I didn't take the time to edit the posts, my time is more valuable than that. Answers that remain without insults are sufficient to cover the tech topic.

naf

iTrader: (7)

EGR allows the motor to run more timing advance at part throttle cruise and can improve mileage. The recirculated exhaust gas lowers combustion temperatures. Deleting it can cause the motor to experience pre-ignition (pinging) at throttle tip in during low throttle cruise conditions which may have to be dealt with by reducing initial timing settings. Some ECMs will adapt by pulling timing via signal from the KS.

MoJoe

iTrader: (5)

To expand on NAF's description...
EGR is ONLY used at warm, part throttle, cruise conditions... think highway. By recirculating some exhaust back into the intake/combustion, it is replacing a little bit of fresh air (oxygen) and gas. This reduces the heat/power/pressure of combustion... a little bit. Enough to reduce emissions, but not enough to noticeably reduce power... you're at part-throttle cruise, so we are nowhere near talking about PEAK power.

You are kind of correct, but it is a matter of degrees..."Unburnt gas" IS the emissions that the cat is designed to reduce. TOO MUCH unburnt gas is what kills the cat, via overheating because it is reducing/combusting too much gasoline in the cat... Continuous mis-firing, or any VERY RICH condition puts to much fuel into the cat. While a very LEAN condition just raises the exhaust temperature to directly overheat the cat.

Just like the human body NEEDS water to survive, yet drinking too much, or in the wrong place (Example: in the lungs) will kill you.

And to address the obvious conundrum: how does adding HOT exhaust gas COOL combustion?
Answer: (stating the above in another way) by replacing some fresh air/fuel, and the inert (already burned, ain't gonna burn no more) exhaust "gets in the way", slowing down the combustion process (allowing more timing) to reduce the PEAK temperature/pressure.

jmd

iTrader: (4)

As said above, it cools combustion temps by introducting exhaust gas to the intake manifold. It's not used under WOT. It improves part throttle mileage.

I've run CCC with and without it functional. I've run TPI with and without it functional. I keep it, as it's beneficial for a car that's street driven.

UltRoadWarrior9

Roger that. My apologies to the OP and posters. Had a long day and vented in the wrong manner.... Back to the topic at hand.

djmarch

iTrader: (4)

Thanks for the input, and yes, if I was going to take that route I would have my memcal programed for such

Wife'sCar

iTrader: (1)

Your welcome, my recommendation though is if it's functioning properly, keep it. It's far more benificial to keep it on a street car

djmarch

iTrader: (4)

Exactly my thoughts on how the EGR system operates. First of all I know what it takes to do such, i.e. block off plate, reprogramed memcal etc...etc.
Here in Virginia, no emissions inspection is required on vehicles manufactured 25 years ago or later. I have deleted my smog pump that cleaned up my engine bay on the passenger side considerably.

My original question was why some members were doing the EGR delete. That's all I was asking for.

Thanks for everyone's input and support...and thank you moderator.

djmarch

iTrader: (4)

Your recommendation taken...

Wife'sCar

iTrader: (1)

Most, not everyone, but most people delete it because it's easier to get rid of it than to diagnose and properly repair/replace it. A lot of people think it's just emissions junk, but this is far from correct.

What part of VA are you located in if you don't mind me asking, I'm in Hampton Roads area.

amfornal

I have a 1989 L98 with smog pump disconnected and EGR blocked off (plated). I have no problems and car runs fantastic. No codes thrown. Intake stays much cleaner now.

naf

iTrader: (7)

'and there was much rejoicing'

Wife'sCar

iTrader: (1)

ASE doc

There are some great and well informed explanations of the EGR system and its function on this thread. It's funny how misunderstood this system is since it's been around for 45 years. I would encourage anyone who really wants to know, rather than just cling to their misconceptions, to do some research. I would expect that Wikipedia has some pretty good info on EGR.

One point I didn't hear mentioned is the fact that smog controlled vehicles need EGR in order to operate at Stoicheometry, which is 14.7:1 AFR. Stoich is key in the healthy operation of the catalyst and, according to the generally accepted science, it's just that happy place where everyone holds hands and gets kissy face. It is supposedly the point where the air to fuel balance is such that the all fuel is consumed in the combustion process.

From an automotive performance standpoint, 14.7: is right at the edge of way too lean. Even these smog controlled vehicles don't run there under any kind of engine load. However, the fact that they do run there during cruise and idle(anytime the system is in closed loop), leads to high cylinder temps. Even though we may not hear detonation, you can expect chamber temps to peak past 2,300f. At this point, oxides of nitrogen are produced during combustion. NOx(not the fun kind) is a noxious, ozone depleting gas that is on the hit list of the EPA. The key purpose of the EGR system, and the reason that tree huggers will hate you for deleting it, is to reduce or prevent the production of NOx. Protecting very lean running engines from high combustion temps is an afterthought.

I don't have EGR on my 87. It's engine is completely redesigned and tuned around max performance. Part of that is writing the timing table and the fuel maps to optimize torque output, which generally means 12.5:1 AFR at full load and leaning down from there as throttle pressure backs off. I may get close to stoich during decel and at idle, but not quite. The timing map is written for max torque also.

With an engine properly built and tuned for max output, cyl head temp is part of the performance equation, not an after thought requiring EGR to control it. An engine built and tuned properly has no need for EGR to prevent high combustion temps. The EPA may frown on our HC and CO output but you can't win em all.

Wife'sCar

iTrader: (1)

That's the thing, if you spend the time and money you can tune a car to run great without it. BUT you are also now running a "dirty" motor and won't pass smog and EPA rules. So you want to keep it on a daily street vehicle for legal issues and we'll as it helps a daily vehicle run good, but you could be getting more out of your engine. So it's a win-lose/win-lose situation. You're losing something on either side of that fence, unless it's a track only car, then ditch that crap lol

blackfrontier

iTrader: (1)

When my 89 GTA 5.7 motor started acting up I had the whole engine rebuilt to factory specs in a GM dealership that I worked for and THEY actually removed the emissions components for me. Why? We don't have emission testing in Idaho, the smog pump was on it's way out and I didn't want to buy another one and I wanted to clean up the engine bay. I personally hate those air tubes that come out of the exhaust manifolds and make it a nightmare to change plugs. In fact we left the EGR in place to "become the block off plate" and caped it off. Result? Car runs perfect! No issues at all. Didn't even reprogram the ECM but once in a blue moon will throw the EGR code which I can make dissapere at any time. I have all the emissions components in a box and can be reinstalled if I ever need to. The engine bay looks cleaner and gives me more room to work. I even powdercoated the plenum, intake runners and manifolds. Looks super sharp!

Wife'sCar

iTrader: (1)

The smog pump system and the egr system are unrelated as far as function and any connections.