EGR experiment (Increase EGR flow for fuel economy)

[old jupiter]

Originally Posted by 2000mc

Entirely correct, except.... Who thought more egr helps power?

Well, I assumed (always a risk) that on a fuel economy site everybody wants to put to good use every BTU that a gallon of gas has to move us as far as possible down the road. I'm not a professional writer, and undoubtedly could have been more clear; I'm glad that Rusty got it.

Maybe "power" is some sort of red flag word here, creating images of hairy-armed, semi-literate rednecks burning rubber with their wildly-cammed big-block '60s muscle-cars. But the power in a gallon of gas can be used in many other ways; I really do share your interest in using that potential as frugally as reasonably possible.

At the same time, it should not escape the notice of y'all that racers and other motorsport people, from pre-depression board track races to the present day, are largely responsible for a lot of power-improving techniques that are basic to the fuel-efficiency you want. Cold-air intake ducts, low-restriction air filters, high-atomization from better carburetor boosters and fuel injectors, low restriction intake tracts that help keep fuel in suspension, porting that promotes swirl and tumble (in 4-valve heads), high compression abetted by ever-improving piston crown to combustion chamber conformation and effective squish areas, quick rise-time high-energy long-duration ignition systems, better ring seal and oil control, better coolant flow to avert detonation-promoting hot-spots, ceramic coatings to reduce unwanted heat losses, dozens of machine shop techniques particularly including ones such as platform-honing with torque plates to improve ring-seal, better bearing materials and shapes, precision balancing, low-friction roller-element valve trains that permit better cam lobe shaping, low restriction and wave-tuned exhaust systems, . . . . all these and more are racing engine-building techniques equally useful to eco-modders.

And it doesn't stop with engines; who you think first came up with air-dams and full fender skirts and "full moon" wheel covers to make a car more aero-slippery? You might even thank the racing community for the excellent braking and handling of modern cars. You think the car company engineers did that without a push? Hardly. After WW2, when stock car racing gained popularity in the late-'40s/early '50s, car company executives began taking trips to the (mostly Deep South) races to cheer on their cars. What they saw was their cars wrecked and drivers killed because brakes faded, spindles broke, suspensions collapsed, transmissions and drivelines fell apart. The suits went home and immediately demanded re-designed components that would stand up to the stresses of competition. Racers paid in blood for the capabilities that production cars began to have in the early and mid-'50s.

[old jupiter]

Uh, got a little carried away there. Anyway, if you aren't interested in power, you're certainly going in the right direction. Keep adding EGR and "reducing pumping losses," and soon you'll have that butterfly in your carb or throttle-body wide-open . . . you'll have to because you'll be making so little of that power you don't care about.

[Daox]

The beauty of EGR in this day and age is its electronic and programmable. So, you can have the best of both worlds. You can have the throttle at WOT with tons of EGR pumping in for good fuel economy, or you can close it and get good power. Why does it have to be one or the other? Many OEMs are using a large amount of EGR in their engines to improve fuel economy, yet power isn't sacrificed. Case in point, the new skyactiv engines use a LOT of EGR and still produce great power, and yeah, you get good emissions too. Win win win in my book.

[2000mc]

Originally Posted by t vago

One more thing - this goes both to the two individuals above who obviously did not read through this thread

I don't know that they didn't read it, but somehow took home a completely different message. I considered making a few similar posts to what you just had, but there seemed to be some sort of serious miscommunication going on. It's like we use the same words, but use and define them so differently, that if they were to speak another language and I put it through google's translator, responded back through the translator, and then posted that. That we would likely communicate as clearly if not better

[t vago]

Originally Posted by Daox

The beauty of EGR in this day and age is its electronic and programmable. So, you can have the best of both worlds. You can have the throttle at WOT with tons of EGR pumping in for good fuel economy, or you can close it and get good power. Why does it have to be one or the other? Many OEMs are using a large amount of EGR in their engines to improve fuel economy, yet power isn't sacrificed. Case in point, the new skyactiv engines use a LOT of EGR and still produce great power, and yeah, you get good emissions too. Win win win in my book.

Yah - When I go to retrofit my truck's engine with an EGR valve, it's going to be one of them electronically controlled valves that are common on late model Chryslers. You know, like the one in the Karen-mobile that was the original focus of this thread.

With the truck, though, since it didn't come with EGR to begin with, I don't have to worry much about throwing an EGR-related code. I can program an Arduino Uno to PWM the EGR valve's solenoid coil, and use the EGR valve's position potentiometer to provide feedback. I will try to get the valve to go wide open during light to moderate cruise, and then shut when the brake pedal is pressed, or when throttle position goes above a certain point. The Arduino Uno should be ideal for the prototype, and I can then construct a custom PCB using an AtMega328, once all the bugs are hammered out of the prototype.

[MetroMPG]

Originally Posted by old jupiter

Maybe "power" is some sort of red flag word here...

That's a bit of a misconception. Poke around here a bit more and you'll discover plenty of crossover between power/racing and fuel economy enthusiasm. Lots of owners of "fun" weekend cars + modified-for-efficiency daily drivers.

At the same time, it should not escape the notice of y'all that racers ... are largely responsible for a lot of power-improving techniques that are basic to the fuel-efficiency you want. Cold-air intake

Maybe not the best first example. Factory warm air intakes can be found on high-efficiency car models. Not good for peak power production, but better for economy (partly for the same reason as EGR -- reduced pumping loss).

[t vago]

Originally Posted by RustyLugNut

And your work wouldn't stand up to the Unicorn Corral requirements.

By your imagination, neither would my aerocap (~10+% gain), or my intake air heater (~5% gain). However, during my last two fillups, my truck would get about 20-21 MPG while driving around at an average speed of 35 MPH. It's (revised) EPA rating is 13 MPG in the city. Explain that.

Originally Posted by RustyLugNut

Here is an example of the testing quality differences.

Am I supposed to imagine what you're trying to show as an example? Here, let me use the power of the Force to try to figure out what you're using...

Originally Posted by RustyLugNut

I don't know what your background is in the physical sciences, but increased EGR for economy gain is as much of fable and legend as HHO. Really.

Prove it.

[Daox]

Here is some proof for you:

http://www.swri.org/3pubs/ttoday/Sum...n-and-Cool.pdf

Their conclusion:

The results showed that, by adding cooled EGR systems, it is possible to decrease fuel consumption by 5 percent to 30 percent, with the largest improvement occurring in the typical enrichment region. The results also showed that EGR can reduce knock, resulting in improved combustion phasing with a corresponding decrease in fuel consumption and exhaust temperatures. Adding EGR led to lower peak cylinder temperatures and engine heat rejection, resulting in improved thermodynamic efficiency and a reduced heat rejection requirement from the engine block. Finally, the high levels of EGR used in the study reduced CO emissions by 30 percent and NOx by up to 80 percent. The results indicate that adding high levels of EGR to gasoline engines is a very cost-effective way to reduce fuel consumption as well as emissions.

[t vago]

Originally Posted by RustyLugNut

Continue with your build, but be more realistic by saying "my data implies", since your data is hardly above scrutiny.

EGR, unlike vapor carbs and HHO and plasma plugs and other bits of nonsense, can actually save fuel. The theory is sound regarding using EGR as a fuel saver.

I'm not writing a graduate-level dissertation, here - not the least because it would waste too much of my valuable time, and certainly not to satisfy your own inflated ego as to how things "should be" done. You should be concentrating on actually showing my results to be invalid somehow, not nitpicking in an attempt to show "possible" inaccuracies and pooh-poohing at an 7.7% improvement in efficiency.

When you actually come up with something useful here at EcoModder, I'll be more inclined to consider your point of view. Otherwise, get out of my thread.

[t vago]

Originally Posted by RustyLugNut

Now, at low-load is where t vago's work might make some headway. But look at the SwRI study where they say increasing EGR results in decreasing torque output.

That's.... um.... the entire point.

Increase EGR
-> decreased torque output
-> increased throttle opening
-> lowering intake manifold vacuum
-> restoring torque output
-> saving fuel otherwise spent maintaining a higher intake manifold vacuum

Really, not that hard to understand.

Originally Posted by RustyLugNut

You will have to plot the torque requirements at a certain speed along with the throttle opening to come to the minimum cooled EGR needed. Your ignition timing will need to be adjusted accordingly. With "no throttling losses", you can gain up to 15% in efficiency, but since you are quenching your combustion and reducing your torque potential you will only see an 8% gain, though some of that gain is also due to the thermodynamic advantage of a lower peak combustion temperature lessening the heat loss to the cooling system.

8% gain is better than nothing, and is certainly well above the margin of noise. That alone justifies adding a $0.10 resistor to an existing EGR system, and justifies spending an extra $50 to add an EGR system to another engine that does not have EGR to begin with.

Originally Posted by RustyLugNut

Now, my posts on this thread have been somewhat facetious

Good to know that you're making facetious posts in my thread. Now, do something useful, or get out.