[t vago]

Originally Posted by old jupiter

What an interesting concept! Mixing an inert gas (exhaust gases) with your fresh intake charge to increase fuel efficiency! And more is better?!! Say, why not just run your engine on argon or dry ice??!!

How much fuel does a gasoline spark-ignition engine require, just to develop and maintain an intake vacuum? Why do you think that BMW and others pursue a production version of intake valve throttling?

Originally Posted by old jupiter

Why do you guys think the factory cuts off the EGR during WOT, when you need the most power out of the air-fuel charge for passing, merging, etc., ??

Because ecomodders here constantly do passing, merging, WOT runs, and other things that require full engine output. Riiiiiiiiiiiiiiiiiiiiight.

Originally Posted by old jupiter

Why do you think racers of every kind do everything they can to PREVENT exhaust gas dilution of the fresh intake cycle, and have been doing this for maybe ninety years?

Helpful hint: We're not racers.

Originally Posted by old jupiter

Why do you think the fire department has inert gases like CO2 in their fire EXTINGUISHERS?

Helpful hint: We're not trying to douse combustion altogether.

Originally Posted by old jupiter

But you are going to show us how to get more power and fuel efficiency from a gallon of gasoline by COOLING the fire in your heat-engine.

No. I'm trying to reduce the amount of non-propulsion work my heat engine has to do.

In the meantime, try to explain to me exactly what is accomplished by creating and maintaining an intake manifold vacuum in a gasoline spark-combustion engine. I'll be right here, waiting.

Originally Posted by old jupiter

Well, when you figure it out, there are a bunch of multi-million dollar NASCAR teams that will pay you very well for your discovery.

Go back to your buddies at DakotaRT.com, and talk about how you and your buddies smoked that Viper the other day.

Originally Posted by old jupiter

EGR is for emissions. Period. If the car makers had not been ordered to find ways to reduce photochemical smog (which they decided to do by cooling the burn), there would be no EGR systems on our engines.

Probably - then again, it's a moot point, because the car makers WERE ordered to find ways to reduce photochemical smog. It's a good thing, too, since that's some nasty stuff.

Originally Posted by old jupiter

If the carmakers had been ordered to prioritize the increase the fuel efficiency of cars above everything else including emissions, there would be no EGR systems.

You do not know that - Given 1970s technology, EGR might still have been a way to increase fuel economy.

Originally Posted by old jupiter

Yes, if you block off the EGR passages (or if the valve plugs with carbon), your engine very likely will run worse.

How is this related to having a controlled increase in EGR flow?

Helpful hint: Engines generally run a lot worse when there is an uncontrolled EGR flow.

Originally Posted by old jupiter

This is NOT because EGR makes an engine run better, but because when EGR is added to an engine, the ignition curve and fuel system calibration are altered to work with the EGR. Basically, because the air/fuel charge is polluted with exhaust gases it burns cooler and slower, therefore the ignition has to be advanced to start the fire sooner.

Ignition also has to be advanced to compensate for high intake vacuum. Why is that?

Originally Posted by old jupiter

If you blank off the EGR (which is what other folks would do to get more fuel efficiency or power or some combination of the two) you are left with an excessively-advanced ignition, yes, the engine certainly will run worse (until you re-curve for the new conditions).

Riiiiight. And all of those mass-produced engine tuners out there (you know, like Hypertech or SuperChips or Diablo) don't seek to deliberately advance ignition curves to improve engine performance. Tell ya what - you stay out of my discussion here, and I'll won't interject my uninformed opinion in any of your discussions that you start here. Fair deal?