why remove egr

[steelzeus]

From my understanding the way that the egr works is by recirculating gas into the intake. Wouldn't that be beneficial because it only operates at cruise and shuts down at everything other engine load. The way I'm taking it is by recirculating the gas it will effectively reduce chamber volume and cool the combustion chamber while also reducing fuel mileage due to reduce fuel demand. Please correct me if I'm wrong but could someone explain why we wouldn't want to keep it.

 

[_JaYvEe_]

egr's are for emissions and fuel mileage

 

[Deepnine]

It makes your throttle body and intake manifold dirty. it also heatens up you coolant, because it's cooled inside the head with the engine coolant.

 

[mitsocruiser]

it cluders your motor compartment it circulates dirty air and fuel back through your intake creating build up in the air intake and your heads is a few miles per gallon worth the life of your motor I removed mine 2 years ago and with my driving style I havn't really noticed any difference in my mpg just be prepared to have your check engine light on If you do a search though you will find several threads and about a thousand different opinions

 

[1992awdlaser]

The only reasons to remove it are:

Less weight
Cleaner engine bay
Less things to fail


You won't have your check engine light come on since it is a 1G.

 

[knochgoon24]

... is a few miles per gallon worth the life of your motor...

How do you suppose it will ruin your motor? There isn't that much build up. I don't understand the logic here.

With gas prices the way they are (or soon could be) I don't really see any reason to remove it. It really doesn't clutter the engine bay that much. What, 1 solenoid, the little erg valve under the intake, and a little vacuum hose? Really not that much clutter. And the whole system is less than a pound.

It makes your throttle body and intake manifold dirty. it also heatens up you coolant, because it's cooled inside the head with the engine coolant.

If you're having cooling problems during cruising conditions (when the erg is actually open) then you'll really have problems with coolant temps when you get on the gas.

 

[talonsteve25]

Mostly the carbon deposts in the intake im guessing.

 

[Deepnine]

If you're having cooling problems during cruising conditions (when the erg is actually open) then you'll really have problems with coolant temps when you get on the gas.

Thats true. Haven't thought that much, i just focused on the egr its self. On the other side the egr cools down the combstion temperature, it might get with egr on even cooler coolant temps. But it doesn't matter, i know.

 

[DSM1G90]

...just some info for the curious on this EGR topic:

"EGR Theory. EGR serves one purpose and one purpose only: TO REDUCE Oxides of Nitrogen (NOx).

Under normal combustion, Nitrogen(N2)Oxygen (O2) in the air and Hydrocarbons (HC) in the fuel combines into water(H2O) Carbon dioxide (CO2) and the Nitrogen remains unchanged. Under very hot combustion temperatures, the Nitrogen reacts with the other two byproducts and forms Nitrogen oxide (NO). After being released into the atmosphere, it picks up another Oxygen atom and becomes Nitrogen dioxide (NO2).

In the presence of sunlight, it combines with other compounds like Hydrocarbons and forms Smog. Since exhaust gas is inert (very stable) it doesn't burn again. So by being introduced into the combustion chamber, it will lower combustion chamber temps enough so that the Nitrogen doesn't react with the other compounds and is passed unchanged out the tailpipe thus not contributing to smog.

Now, since exhaust gas doesn't burn, it doesn't exactly help with combustion. At higher RPM's, this really isn't noticable, but at idle, the reintroduction of exhaust gas will cause a very rough idle and can cause stalling if to much is introduced into the combustion chamber. (Like sucking on the end of the exhaust pipe through a straw - how hard is that to breathe normally....)

The design challenge: The EGR system of today must precisely control the flow of recirculated exhaust. Too much flow will retard engine performance and cause a hesitation on acceleration. Too little flow will increase NOx and cause engine ping. A well-designed system will actually increase engine performance and economy. Why? As the combustion chamber temperature is reduced, engine detonation potential is also reduced. This factor enabled the software engineers to write a more aggressive timing advance curve into the spark timing program. If the EGR valve is not flowing, onboard diagnostics (OBD-II) systems will set a code and the ECU will use a backup timing curve that has less advance to prevent engine ping. Less timing advance means less performance and economy."


-DSM

 

[DSMboostin15]

That's some good info. I've always wondered how the EGR actually contributes to emissions and I didn't know that it could actually HELP with performance. Thanks for sharing that.

 

[DSM1G90]

Kinda makes sense then why the 7bolt was introduced along with the improved OBD-I system for the current 1Gb and the up and coming 2G vehicles which got the OBD-II systems: You got the increased compression ratio from 7.8:1 of the 6bolt to the 8.5:1 for the 7bolt. Then you have the EGR in the system cooling the flame to where larger timing curves could be met to give that stock motor 20bhp more than the 6bolt - along with the faster spooling turbo of the Garrett T-25.

....This was all done ... FOR THE VEHICLES SOLD ON THE SHOWROOM FLOOR!

All info above and in the previous post pertains to stock setups when the vehicles left the factory. I'm sure that, in modded setups, a lot of situations that have been either altered or modified, cancels out all topics of this discussion.

Course, we also have to take in consideration that the stock system needs the Ox2, temp, MAF and everything other sensor to be in the closed loop with the ECU to ensure maximum performance and economy in this spectrum as well.

Someone knew what they were doing with the 7bolt motor in that design setup. Just too bad some cranks had problems with the crankwalk issues being the effect of a poor design cause for this motor.

 

[Defiant]

We just did this thread two weeks ago.