Increasing EGR flow for better mileage

[Daox]

I took some time this weekend to work on the EGR valve pwm controller. I repaired the pwm circuit, but it still didn't work. It wouldn't allow me to adjust the duty cycle low enough to close the valve. So, I went with the arduino to control the pwm circuit. I had an extra mosfet from the pwm circuit, so I used that. It works great. Here is a video.

http://www.youtube.com/watch?v=JMf19gL7oNc

[MetroMPG]

Nice work. You're the EGR pioneer on EcoModder... soon you'll be famous!

What's next? (Other than waiting for milder weather to go play in the garage again.)

[Daox]

Well, next is reprogramming to allow actuation with a pot. This is already done, but needs to be tested. After that, I will fab up the works and putting it on the car to try out.

[Daox]

I updated the code tonight to work off a potentiometer. Works great. Horrible video, but it gets the point across. I'll be able to adjust the valve from the cabin easily.

http://www.youtube.com/watch?v=Ntvv9fykyDo

[MetroMPG]

Nice work, again.

So how complex is the plumbing going to be to try this out in the car?

[Daox]

The plumbing will be pretty easy. I have an extra exhaust manifold that I'll be modifying to collect the gas out of. I also have an intake manifold from a Paseo with EGR that I can use to reintroduce the gas into the engine. I'll have to fab up stuff between, probably just use iron pipe.

I will have to run coolant to the EGR cooler. I'll likely just grab that off the throttle body coolant lines.

[Christ]

Where does the EGR flow into the intake? I think a large part of this working the way you want it to will be whether or not the EGR flow actually makes it evenly to all the cylinders. You don't want a couple getting good flow, and a couple not getting much at all, cuz that could cause problems.

[Daox]

The stock location for the EGR introduction into the intake system is directly behind the throttle body on the intake manifold. When I get to fabbing the stuff up I'll get pictures of it all.

For now, I have these bad pics of the intake manifold. The odd boss with studs coming out of the back of the manifold are where the flange bolts up for the EGR.






Here is another angle. Notice, no studs. This is just because its a non-egr manifold.

[Christ]

I see. Looks like they already solved the distribution problem for you!

EDIT - Are you going to modify that manifold to work? i.e. drill and tap the stud and port locations?

[Daox]

Nope, I have a manifold off of one that has EGR, so I just need to make the flange to bolt it up.