hi can i remove the egr system without ajusting anything. Is this a good thing and if so can i get a cover plate for the back of the intake. Will the car run ok without it. thanks,kirk

 

why would you want to do that?

EGR is not the Devil as bubba says...

Truth be told, that EGR valve has saved your engine from self destructing more times than you could possibly know...because it did its job without you even being aware.

Does EGR rob an engine of power? No. Thats a myth. Ignorance keeps that story alive.99% of the folks that say that it does steal power cannot describe what EGR does or how it works and why. The only time that might happen is when/if the EGR system were to malfunction. Thats unacceptable to some, but driving around with 3 dead injectors seems to be ok. Remember, fuel injectors were the devil in the 70's. Disk brakes were the devil in the 60's. So were radial tires,. and unleaded gasoline. As the fog of ignorance disapated the clarity of fact prevailed. All these things are now standard issue in the automotive industry.

Is EGR harmful. No the opposite is true.

Whats the purpose of EGR?
it prevents the engine from meltdown from extreme combustion temps and aids in the immediate end of knock or more exactly, PING (pre-ignition). Between EGR and ECM knock sensing the conditions that allow PING can be negated instantly with the introduction of cold gases in combustion and retarded timing for a micro-second...or two. The 2 systems are not necessarily linked together, but they both work to end a deadly condition that will result in broken aluminum pistons, bent rods, broken internals in general, Bad stuff...

Much like PCV the EGR is there for good reason. If you want to keep an engine in one piece that runs at higher temps, leaner AFR (more precise AFR which is why that engine will last 250,000 miles) and perform well, you need both.

The ONLY valid reason to remove EGR is for a race car thats track-only. And tuned for such.

Hope that helped. I hate to see people do things that will end up biting them in the a$$ hard, somewhere down the road when there was no real reason to mess with it in the first place. If its not working, fix it. If you do not understand it, learn about it and I can assure you when you DO, you will want it there and you will feel better about running the engine to its potential, knowing there are built in systems that will help prevent meltdown should you go too far one day. Because when its all working as it should, there is no knock, no ping, no clattering, nothing odd at all. Because these things are all doing their job.
Are they added complexity? you bethca. Thats the computers problem, not yours.
If you want to run fast, run hard and still get MPG in the high 20's, and look good during the process, thats what it takes.

 

EGR was only ever installed for smog/ mileage purposes
As it is only activated under light load conditions ( because it reduces power under high load) ,
it has no effect if the engine is approaching the meltdown conditions you mention which only occur
if the engine is under load.
The knock sensor takes care of pinging / detonation problems

EGR is either on or off depending on the parameters programmed in the tune; it does not come on for micro seconds to solve a detonation problem

 

Ok, I respect your opinion and I ask that you respect mine as well.

Although EGR might be primarily a smog device to maintain the balance between High NOX and low HC by reducing combustion temps it has an obvious beneficial side effect of preserving the engine by preventing these extreme temps from doing damage.
2000 degrees is too much for a turbo and certainly will do damage to aluminum and other semi-soft metals if allowed to continue more than briefly (micro-seconds, mili-seconds, momentarily etc..)

Jeeze...I haven't done the math, but its a safe bet that during the combustion cycle of a single stroke at 3500 rpm when an excess combustion temp takes place due to load or other conditions, its BRIEF. very very brief...possibly mili-seconds? damn. My PP vocabulary is limited to the more common adjectives. Apologies.

EST, knock sensors work to stop knock caused by incomplete combustion, a completely different event but equally as damaging for different reasons. Either way, thru high temp or the physical stress of knock or piston rattle, these hypertheuretic/????(sp?) pistons do not do well under these conditions.They are engineered to disperse heat and be light-weight. Not rattle and absorb low frequency shock like high temp combustion knock. If you want to let your cans rattle, go spend the money on forged parts that are designed to do so. ..cause the stock pistons ain;t gonna last long rattling around or in excessive combustion temps.

Ping is another issue altogether..one that most people confuse with knock but I'm not here to define the difference....but there IS a difference. I WILL offer this ....its got to do with temps.

BTW, micro-seconds, mili-seconds,instantly, right now, immediately, all synonomous of now, briefly or quickly and are just expressions, figurative statements, not literal. Interprit as you will...nit-pik if you must.

I did not see where you'd approve of deleting the EGR in a street engine? or was the purpose just to critique my opinion? You are welcome to do so as long as you understand that each of us is entitled to their opinion.

Just for clarity, IMO, EGR serves a larger purpose (than a smog tool)and does no harm. If the 2 HP loss (<-another damn figurative statement) when briefly ( or mili-seconds?, lets just go with "briefly" to avoid any confusion) activated is a big deal to the driver/owner then I'd suggest he go find some more ponies to negate the minimal & temporary loss of power from this device. The side effect of sparing the engine from excess temps is far more acceptable than the risk of damage over a couple HP that will never be missed...or noticed.

Of course, thats just my opinion.....

 

The 1996 LT4 motors did not have EGR from the factory. Just sayin...

 

Well i had my EGR vacuum disconnected for more than 10 years, so it never operated. The 85 vette went from naturally aspirated, to supercharged with intercooler and i did not want to loose boost so i kept it disconnected. Now i never had any knocking until a couple of years ago, i fitted the wrong ESC module when i threw some parts at it that turned out to be an bad injector connector. I did re-activate the EGR valve as a test but it still pinged in summer with 230f-240f coolant temp. Last week i discovered my old ESC module while cleaning the garage, ping/ knock is gone turned out i had the 89 type module. (have found out the knock sensor and esc module are a matched part hence the original esc module works) I did not notice any loss in performance as the EGR is only pulsed on during highway cruise and any acceleration shuts it of. Still the thought of HOT DIRTY exhaust gasses getting pulsed back into the inlet (not evenly to all cylinders either) is disgusting. While i do not have to pass emissions i did not notice any coolant temperature difference either with EGR on or off. As long as the ecm monitors and adjusts fuel injector pulse widths to keep the air fuel ratio correct there is no problem. Just the annoying EGR code as it has been disconnected again. But that can be resolved with reprogramming the ECM chip.

As for engine damage, when i removed the original 1985 built 350 with 170,000 miles. (That had been supercharged 6 and 8 psi boost for the last 6 years) to fit my new 383 all was good in the old engine, it just needed a hone and new rings to double that mileage again. The rings were worn an no longer sealing well, no smoke blown just blowby needing extra crankcase ventilation. Heck even the heads were in great shape.

As for aluminum heads well that is a different thing, with dissimilar metals galvanic action and electrolysis is a part of life. Head gaskets and shaving the heads will need to be done, depending on how well the anti corrosion inhibitor balance is maintained.

 

Not disputing your analysis , just pointing out that on our cars EGR is not active when the problem
conditions you detail exist ; under load.

Each to there own, I don't believe it is subject to get emotional over
Mine was on until did major mods and had the ability to adjust the tune to delete it correctly .
Physically removing the EGR without deleting it's operation in the tune will give excessive spark advance when the ECM
commands EGR operation on the valve which is no longer there.
The feedback to the ECM only tells if it is working or not ; if not seen to be working it throws a code .
The ECM will not stop it's programmed EGR operation if it sees it not working and will continue to advance
the spark which it is programmed to do when it thinks the EGR is active

 

To answer your question I would say you cannot remove it without getting a tune change to eliminate it and a cover plate. If you do not change the tune you will get a check engine light, and possible part throttle knock retard because the tune adds in additional timing for EGR operation and the car will not know if the EGR has been removed.

EGR's only purpose is to reduce NOX emmisions at part throttle, it does this by adding in exhaust gasses to the intake charge to dilute the intake charge and causes the flame temperature in the combustion chamber to burn cooler, less then 2500 degrees (NOX is created when flame temperatures exceed 2500 degrees). EGR's negatives are that it reduces your mileage because it causes the combustion to be less efficient by increasing the pumping losses of your engine. It also heats the intake charge increasing the chances of preignition and detonation along with reduced efficiency. Manufactures try to reduce the negative effects of EGR by adding in additional timing when EGR is operating but the bottom line is removing EGR will not hurt the car but can increase the NOX emmisions as long as the tune is adjusted for the EGR elimination. (Your gas mileage sould increase slightly with EGR removal)

 

Nor did the RAF in WW2 - they used water to control detonation. The OEM's wanted an infinite supply so they choose exhaust as their substance to keep combustion temps under control.

Later designs have eliminated EGR because the CAM profile allows more overlap which keeps exhaust in the combustion chamber longer which accomplishes the same thing. Today's variable valve timing is even better or Lamborghini's spark plug that incorporates an O2 is about as good as you can get

 

PS - the bad rap isn't unfounded if you go back to '73, the first year it was mandated by the Feds. Actuated by a vacuum solenoid and backed by a meager 12/12 warranty, they leaked within short order or the solenoid would break (GM only produced the '73 model for 18 mos and there were no replacements once it broke). Add in carbs that were leaned to the max, the idle was poor (if they idled at all) and it typically stalled at every 3rd stop light. Chrysler K cars were even worse - particularly going uphill under light load where the motor would simply quit (why in the hell Congress saved it eludes me). It wasn't long before enthusiasts figured out that a BB in the solenoid vacuum hose plugged it for good and with the caps off the idle screws, you could fatten the mix for a halfway decent idle.

 

I've had mine removed for over a year and 10,000 miles. Also removed the AIR system. For 94 and 95 you don't need a tune, just leave the EGR solenoid and connector hooked up so the PCM still reads it. No problems or codes here. Haven't noticed or recorded a difference in mileage either. I've thought about reinstalling everything just for originality. But having all that clutter out of the way sure makes it easier to work around the engine.

 

[QUOTE=vetteoz;1582765238]Not disputing your analysis , just pointing out that on our cars EGR is not active when the problem
conditions you detail exist ; under load.


It does operate under a load, and it will reduce ping/detonation. It only allows a very small amount of anert gas to flow so it will not affect engine power..

http://www.aa1car.com/library/egr.htm

 

Doesn't say anything! there are several differant ways to control NoX created by high cylinder temps..

 

They did have more valve duration, lift, overlap on the cam. This design left some exhuast gases in the cylinder. So no need for the EGR.

Newer vehicles use Variable Cam Timing to the same effect. Most newer vehicles do not have EGR valves.

Back in carb days, EGR's where junk but since the advent of electronic fuel injection say 25 years ago or so, they do not hurt performance.

They are there to lower combustion chamber temps. by mixing in burnt exhuast gases when instructed to do so by the ECM or PCM.

EGR is used ANYWHERE other than idle, cold engine operation, and WOT. Helps with detonation, emissions, fuel mileage, etc...the details of which can change from car to car, make to make. They do operate under load, get scan tool and go for ride some time. You'll see just how much it does operate.

Just to throw you guys a curve ball, the EGR operates under deceleration.