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how to by pass an egr valve


Guest Eurolumina92

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You wont see any power gains from removing the EGR. You may feel better throttle response at part throttle, but no actual gains. But, your intake runners and intake valve will be MUCH cleaner. You will need to have your ECM programmed for no EGR

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That will work, but the ECM bases its fuel delivery partly on EGR %. B/c the exhaust gas cools the combustion chamber, if you run with no EGR, and dont program the ECM for it, you will run lean and hot

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re: lean condition

 

Ok. I always thought blocking off the EGR would lower intake temps since you're not recirculating hot exhaust gasses, and provide a better 'bang'. But, let's say combustion chamber temps do rise.. and the car runs leaner.

 

In closed loop, wouldn't the ECU use the o2 sensor feedback and if it detected a lean condition, dump more fuel?

 

as far as open loop, how does the EGR operate under WOT/open loop in GM cars? Does it close? If it does, you've nothing to worry about, since the factory fuel maps would account for the EGR being closed under WOT anyway.

 

feel free to shoot my ideas down.. lol.

 

as far as perf gains, I don't think you'll see too much either.. but it does help keep the intake manny clean.

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you can cut a piece of a coke can in place of the gasket to block it.

As far as making the intake temps cooler, i doubt it. hotter if anything.

fuel makes the temps cooler, the egr adds exhaust gas from higher steady engine rpms (exhaust is rich at higher rpm's) to the intake to help emissions, basically recycling the exhaust by reintroducing back into the intake. The EGR is basically a different air pump.

If you block your egr you will probably just have a <code for the egr- not functioning> at cruising speeds over 60mph. This is only if your car is OBD1, OBD2 will be on continuously.

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re: lean condition

 

Ok. I always thought blocking off the EGR would lower intake temps since you're not recirculating hot exhaust gasses, and provide a better 'bang'. But, let's say combustion chamber temps do rise.. and the car runs leaner.

 

In closed loop, wouldn't the ECU use the o2 sensor feedback and if it detected a lean condition, dump more fuel?

 

as far as open loop, how does the EGR operate under WOT/open loop in GM cars? Does it close? If it does, you've nothing to worry about, since the factory fuel maps would account for the EGR being closed under WOT anyway.

 

feel free to shoot my ideas down.. lol.

 

as far as perf gains, I don't think you'll see too much either.. but it does help keep the intake manny clean.

 

Im not real sure why EGR lower combustion temps, but I do know lower combustion temps mean better emissions. I think the lower temp has to do with the fact that the exhaust will still ignite and not burn near as hot, and since it still ignite, the computer can but in less fuel. Fuel burns hotter than recirculated exhaust gas. Now, for the closed loop stuff. Yes, over time, the ECM should, with the help of the O2, bbe able to compensate for no EGR. But when you first take it off, the stock fuel tables wont be right. At idle and WOT the EGR is closed. Its only open in light throttle situations. By not having the EGR, you might feel better throttle response around town, b/c its normally open in light throttle situations, so the car will "feel" faster, but its really no. Hope that helps

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(exhaust is rich at higher rpm's)

 

The ECM leans out the mixture as throttle increases. The air fuel goes to around 11:1, I think, at WOT. It tries to maintain the theoretical perfect ratio of 14.7:1 when idling or light throttle

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wow robby, how did you get so smart:P

 

Fuel is based a lot on egr with the start of the digital egr in 91. The fuel constant is based on EGR %

 

EGR gas cools down the combustion process because it is inert gas...aka you can't burn it. The computer compensates fuel for the inert gas taking up space in the combustion chamber.

 

I have never seen a dyno comparison of EGR on vs EGR off, but my best guess is 0 difference at WOT, cause the EGR is closed anyway.

 

http://www.60degreev6.com/phpBB2/viewtopic.php?t=315

 

Discussion on 60v6.

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