Egr Removal

[907mge]

Im replacing the head gasket on my 90 7mge and would like to remove the egr but don't know if it will kick the cel on. The car is from PA and not a Cali car. Also i want to know if it is a bad idea or not. It would be nice just to clean up the engine bay a little

[supra.7mgte]

shouldnt have a problem but there are some vacuum lines that you will need to plugged off. and a couple of block off plates made to the egr vavle on the head and the intake... i would tell u what your car my run like after u remove it but i have yet to get my to start due to no spark

[cre]

It's a stupid move given how the kick you'll see in combustion chamber temps, reduction in spark advance and reduced mileage... but, if you must you should source a JDM ECU, it's tuned to run richer and with less spark advance to compensate for the higher engine temps.

And, no, deleting the EGR will not cause any diagnostic codes in any 7M model except for the California spec ECU.

[907mge]

im curious of how it reduces combustion temps and where does the exhaust come from?

[cre]

I don't understand your question...

Exhaust gasses come from the exhaust side of the head, run through the EGR cooler and then through the modulator valve into the intake.

[907mge]

i mean how does hot exhaust lower the temperture of combustion?

[cre]

Because exhaust gas is a LOT colder than burning fuel perhaps?

Here's the simple version: After the fuel mixture is burned a MASSIVE amount of energy is transferred as heat and kinetic energy, the rate at which exhaust cools after the combustion process is very fast, then the small portion which is rerouted is run through a cooler at the back of the head where the temps are pulled down even further. The gas which remains, while hotter than the fresh air coming in (usually) is also inert meaning it doesn't burn when the next combustion cycle occurs... less burning mass less heat. less heat, less knock. less knock, the more timing advance possible. more timing advance, more power per a given amount of fuel. In the end there may be a *tiny* reduction in power, but only at certain points in the operation of the engine. and we're talking MAYBE 5HP... maybe.

I don't know why you're so worried about it other than "it doesn't look purdy"... I'm pretty sure that on the 7M-GE the system isn't even active when you've got it floored.

BTW, did you know this is how Honda get's such crazy good mileage out of their cars and is able to run their engines on fuel mixtures as lean as 60:1?

[907mge]

that you for the explanation i'm still learning about the different systems

[cre]

No problem, if you're not sure ask.

[907mge]

After seeing the head and intake apart i see where the exhaust gas comes from, going from the back cylinder to the y pipe. What i also noticed is the huge amount of carbon in the intake. Isn't that bad for air flow?