Thread: EGR with header
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Old 03-03-2011, 02:15 PM   #7 (permalink)
nimblemotors
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Quote:
Originally Posted by Daox View Post
Mmmm, nope. Exhaust is positive pressure (vs atomosphere) and intake is negative, so EGR naturally flows to the intake.
What I was trying to say is that if you connect a tube to the exhaust flow, having it point downstream would reduce its ability to extract the flow,
having it face INTO the stream would increase it, I'd think. The stock EGR connection seems to just be a 90-degree opening to the exhaust stream.
I'm thinking of using a U tube bend that is inside the stream.

Quote:
The head will actually cool the EGR. However, on diesels and the 3rd gen Prius, they are using exterior EGR coolers so that you can run higher amounts of EGR which can have fuel economy advantages. I've been messing around with this idea, but have yet to actually fabricate/make anything to test it.

http://ecomodder.com/forum/showthrea...eage-7358.html
thanks for that reference, I did a quick search and didn't see it immediately.
So they route it through the head to cool it? well that heats the head, my concern is it imbalances the heat to that cylinder next to the passage.

The advantage might be to shorten the warm-up time, which we know is important, In fact, I was thinking of routing coolant around the exhaust to heat it up faster, then it could be turned off once the car is warmed up.
For a distance commuter as this car is designed for, warmup time wouldn't be a factor and I don't want to complicate this car, but might consider it for the Boxster.

So it sounds like it would be a good idea to run a long tube down to past the muffler to tap into the EGR source, and by-pass the head passage, and connect it to the stock EGR right now. If I get to replacing the ECU with my own, I might replace the EGR with an electronic controlled version.

Jack Murray




Having EGR on during a cold start up or at idle is probably not the best idea. It will most likely prevent the engine from running smoothly. The OEM systems do this automatically and should be retained to ensure proper engine operation.[/QUOTE]
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