EGR or Not ??????

[Phatman]

How many of you have removed your EGR valve? What do you think or what have you been told the advantage is to removal?

Is there any real performance gains for a car that is not in the 10 sec. bracket, or do you just feel it cleans up the engine bay?

While I'm thinking about it what about the vapor can?

 

[sixgun86gn]

I have no idea what improvements there are.I have a ported intake with a milled out EGR and it is welded up.It probably helps intake flow.I haven't noticed any driveability problems caused by not having it.Besides its one less thing to start messing up on me later.

 

[ChrisCairns]

If you drive the car on the street leave it in. It lowers combustion temps while cruising and won't detract from WOT performance since it isn't in operation at WOT.

Ditto on the canister....it doesn't take away from performance and sucks the excess fumes out of the tank.

 

[Phatman]

Thanks for the replies....

 

[bruce]

Originally posted by ChrisCairns
If you drive the car on the street leave it in. It lowers combustion temps while cruising and won't detract from WOT performance since it isn't in operation at WOT.

While it's not commanded to work by the ECM, at WOT, exhaust back pressure can open it at WOT.

I had sandblasted my intake so that it was spotless, and then several months later, gotten an EGR Block off plate and the intake side of the EGR port, had carbon in it. The only way for the carbon to get there is if the EGR valve had been opening.

 

[Eric Stage I]

Bruce, that's interesting. I was thinking that boost would keep it closed, but now that I think about it, there's a check valve in the vac line that goes to the egr stuff. So I guess its not boost referenced. Hmm...


Eric

 

[ChrisCairns]

Originally posted by bruce

The only way for the carbon to get there is if the EGR valve had been opening.

Or leaking.

 

[gofstbuick]

Originally posted by bruce
While it's not commanded to work by the ECM, at WOT, exhaust back pressure can open it at WOT.
The only way for the carbon to get there is if the EGR valve had been opening.

The EGR valve can operate if there is the correct amount of exhaust back pressure, but it takes vacuum to pull the valve open. Where is the vacuum under boost (especially at WOT)? Additionally if the computer does not complete ground to the solenoid at WOT, the vacuum passage should stay closed. As Chris has stated previously, maybe it was leaking. To be more specific, maybe one or both of the gaskets (used for the block off plate) leaked between the exhaust and intake passages. I have seen people use beer can aluminum to create a block off plate and usually it leaked between the passages. Since I don't know the configuration of your block off plate, I can only speculate.

The EGR should not rob performance at WOT (assume solenoid is not energized). During part throttle, spent exhaust gases take up space in the combustion chamber (when the EGR is activated) in an attempt to cool peak cumbustion temperature. If you block it off, and combustion temps rise high enough to create a detonation issue, and the computer initiates timing retard, where is the performance gain in that? Typically, the EGR solenoid will not activate at WOT and in open loop. Operation in open loop may cause drivabilty problems (stumble; remember 73 and earlier GM and MOPAR products that did not even use a temp switch) and operation at WOT may cause lean out (self defeating).
IMHO if the car is driven on the street and subjected to loaded mode type emissions test, leave it on.