Removing EA82 EGR Advice

dommie13 · Post by **dommie13** » Sat Aug 01, 2009 8:36 am

Hey,

I'm currently doing the head gaskets on my Carb EA82 and I'm pretty keen on removing the EGR.

I would just like to grab some opinions on this and whether or not it's going to be a good or bad thing.

Cheers

,Dom.

steptoe · Post by **steptoe** » Sat Aug 01, 2009 9:46 am

search the terms in here to find more detail, I found I got a half litre per 100km better economy with mine operational, it is only supposed to work within certain parameters such as op temp and within about 1 to 10 inches of mercury manifold vacuum light throttle cruising, shuts off when you are asking for power and at idle or cold. Rego inspectors in most states look for its existence.

Gannon · Post by **Gannon** » Sat Aug 01, 2009 10:00 am

Probably a bad thing.

EGR only operates during cruise (part throttle) and is designed to reduce pollution and save fuel by decreasing intake vacuum the associated pumping losses.

So unless it is not working properly, id leave it there

dommie13 · Post by **dommie13** » Thu Aug 06, 2009 9:26 pm

Alright, sounds like a waste of time removing it, it can stay on.

Thanks for the advice guys

Suby Wan Kenobi · Post by **Suby Wan Kenobi** » Fri Aug 07, 2009 7:19 pm

My engine was running rough but once the EGR was removed it ran better and fuel ecconomy was improved. In my case the valve itself had siezed partially open.

steptoe · Post by **steptoe** » Sat Aug 08, 2009 10:03 am

yeah, it does make sense to check these gadgets on 20 year old engines. To do this I got another, T pieced it its vacuum source, long piece of vacuum hose and ran each as a spare into the cabin where I could stick me little finger against the diaphragm and feel when each was working as I drove. Helps develop an understanding of how and when it works and blows away the claim that to remove EGR or disconnect its vacuum supply or the path of recrirculated air - gives another 10kW. CRAP

Porty · Post by **Porty** » Sat Aug 08, 2009 9:27 pm

I don't have access to a dyno or any sofisticated engine testing equipnment... So what im saying is my personall opinion.

I don't know exactly when the ea82s ECU decides when it wants to give my girl a puff on a ciggarette.. But i do treat my car as if she was alive... I know if i had just run a k or 2 then was stoppin for a rest then got up to go again i wouldn't wanna suck down a pack of winny golds to help me get goin again...! I don't want her breating exhaust gases at her age.. Lol.. Call me a hipocrite, i smoke myselft... lol..

Anyways anyone can google up on it all they like... But until someone has fully tested their baby in exactly the same conditions, with the valve removed or not, is when we can all make a final decision on it...

U know what mothers say "breast is best".. Well in my case "fresh is best"...

steptoe · Post by **steptoe** » Sun Aug 09, 2009 11:38 am

one good reason for your girl to rebreathe a bit of exhaust at times of no demand is so we humans can keep breathing good old fresh air - there is a few other side benefits out there for plants and animals etc. Have you also over ridden the efi injectors so they spray fuel above 1500rpm and throttle closed? Coz your ECU does! - part of efi fuel savings

Porty · Post by **Porty** » Sun Aug 09, 2009 4:26 pm

steptoe wrote:Have you also over ridden the efi injectors so they spray fuel above 1500rpm and throttle closed? Coz your ECU does! - part of efi fuel savings

I don't know exactly what ur saying here..?

steptoe · Post by **steptoe** » Mon Aug 10, 2009 10:10 am

you say fresh is best and you prefer to not to have egr working or rather feed in exhaust gas. What about your fuel requirements? If you run efi (you mention ECU) the ECU activates an injector cut out above 1400 or 1500 rpm when throttle is in closed position and turns injectors back on below that rev range and as soon as TB opens again. Thought maybe you may have over ridden that ECU function to keep fresh fuel in your baby all the time

. Fro what I understand the egr functioning helps reduce combustion temps at the times it operates and keeps NOX readings within requirements without harmimng power or performance

Porty · Post by **Porty** » Mon Aug 10, 2009 6:53 pm

steptoe wrote: What about your fuel requirements? If you run efi (you mention ECU) the ECU activates an injector cut out above 1400 or 1500 rpm when throttle is in closed position and turns injectors back on below that rev range and as soon as TB opens again. Thought maybe you may have over ridden that ECU function to keep fresh fuel in your baby all the time .

I don't rember mentioning anything bout intercepting the TPS and CAS signals then on the certain condition keep firing the injectors at the time of TPS shut and CAS > 1500rpm just so i can keep pumping fuel into her without air and basically choking her.!

Speaking from what ive read and not what ive tested in the real world......... Yes! recurculating exhaust gases and slowing the rate of combustion dose reduce the somethimes sudden heat spikes in the combustion chamber that cause NOX.

I know the subaru ECU programmers arn't stupid so i guess they would only let the EGR open at certain times so as to not affect driveability.. again i don't know when these times occur and really don't care, its just a personal preference for me. I just prefer not recurculating it...

Gannon · Post by **Gannon** » Mon Aug 10, 2009 7:34 pm

Ok

EGR has nothing to do with fuel cut on deacceleration.

EGR serves 2 purposes.

1. Reduce oxides of nirtogen.

2. Reduce fuel consumption

A reduction in NOx is achieved by lower combustion temperatures through dilution of the intake air with exhaust gas

A reduction in fuel consumption is also achieved because the diluted air/fuel mix creates a smaller bang, less power is produced and the driver unknowingly presses harder on the accelerator pedal. at this point you may think this is a bad thing, but stay with me...

Because of the wider throttle opening, manifold vacuum drops and the engine doesnt have to work as hard drawing air past the partially open throttle plate.

This gives the engine a lower specific fuel consumption per horsepower produced.

Dont worry about the EGR sacrificing power, it only works when there is high manifold vacuum (cruising throttle) and the engine temperature is above 63degC

As soon as you mash the pedal, EGR switches off and you are sucking in pure oxygen

steptoe · Post by **steptoe** » Tue Aug 11, 2009 10:47 am

the 3 plug ECU of the 85,86 made models is supposed to only activate the EGR at operating temperature below road speed of 45 kph and not at throttle closed position. The vacuum alone controls the 0 to 10 InHg opening so long as ECU parameters are met. That is what the manual states. My ECU is lazy and only stops op at closed throttle. EGR works cold and at all speeds