Netwrkengeer

Why Seal EGR?

It is my understanding that the EGR is ment to cool the cylinder.

How does sealing it help.

luckyou03

The EGR lets really hot exhaust gases back into the intake, and causes the LT1 rear intake manifold leak. It also "clutters" the engine bay.

breakmyfootoff

It recirculates exhaust gasses back into the intake to try to burn any leftover fuel that didn't get burned on the first pass through the engine, thats also the omly purpose for the catalytic converters, to try and finish burning any unburned hydrocarbons before the hit the atmosphere. Both are devices are just to lower emissions. As stated above, deleting it will keep the hot exhaust gasses from re-entering the intake as well as the already burned fuel. I don't think it makes much of a difference, but every little bit helps. And like the guy above said, it removes clutter from the engine bay.

Bawls

How does something hidden behind the intake "clutter" the engine bay? EGR doesnt clutter the engine bay up at all, A.I.R. does however.

I've personally removed my egr because of it sticking open/close every now and then.

BLinindoll

Not true at all. I puts used exhaust gasses into the cylinder to displace oxygen. less oxygen = cooler burn = less NOX = less emissions. exhaust gasses are also added if there is knock detected. by cooling down the burn, it creates less knock.

shoebox

Some think that you must get rid of every emissions system on the car to get the most horsepower. Not true. The EGR only operates during part throttle conditions and lowers combustion temperatures (and emissions) when necessary.

Some suspect it of causing the intake leak, but that is just a theory. The real cause, IMO, was the inferior sealant used.

Others need the EGR blocked off because they have non-emissions headers with no EGR provisions.

Netwrkengeer

So basically during idle and anything other then WOT the EGR will allow Exhaust to mix with the intake's gas and air mixture?

BLinindoll

No. Only at certain times of part throttle, and I believe only under 3000rpm's or so. I'm not exactly sure on that one. The certain times are when emissions are too high or if you are getting knock. (High combustion temps cause knocking.)

Injuneer

EGR is used to quench combustion chamber temperatures at times when elevated temperatures would increase the formation of oxides of nitrogen (NOx). A common cause of this would be lugging the engine up a hill at too low an RPM in the wrong gear. That elevates combustion chamber temps, which causes NOx to form.

Since the introduction of EGR reduces combustion chamber temps, it will also, as a side benefit, reduce the tendancy for th engine to detonate (knock). But I have never seen any evidence that EGR is actually used in response to knock detection. It wouldn't make any sense, since it isn't operated over about 3,500rpm, or at WOT, and its WOT when you are likely to see detonation. I'd be interested in seeing the documentation that shows EGR is used specifically in response to knock detection. I've looked at a lot of data logs over the years, and can't recall seeing the EGR duty cycle go up when knock retard is invoked.

EGR and AIR do not hurt your performance in any way, because they don't operate at WOT. The EEC purge system does operate at WOT, but that's simply flowing a small amount of hydrocarbon vapor, mixed with air into the intake manifold.

I built an 800HP nitroused stroker, and managed to keep all the emissions systems intact, and had a car capable of passing NJ rolling emissions while still producing 500 flywheelHP. I didn't see any loss of power from having those systems hooked up. Only when the car was permanently removed from the streets, and turned into a "track only" car did I delete those systems to save weight.