Lean burn, EGR, CAM timing vs BSFC quantified

[dieselbenz]

http://www1.eere.energy.gov/vehicles..._lymburner.pdf

A screen shot from the PDF that summarizes things nicely. The document focuses on NOx emissions mostly but the BSFC info might be useful to some. The engine is a 5.4 liter Ford 3 valve V8.

[pgfpro]

Nice find!!!

Great article.

[pgfpro]

I love the fact that they used a "BMEP" (4 BAR BMEP) as a reference. This is something every BSFC chart should have included.

This article has gave me some new inspiration and some new ideas that I can implement.

[dieselbenz]

Yeah it actually got me motivated to try and trigger EGR through MS2 under very specific conditions. Without EGR I can only lean it out to a little past 16 before lean surge. With EGR turned on I've taken it to about 17 so far, no lean surge yet. This is NOT a lean burn any by any standard.

[pgfpro]

Originally Posted by tjts1

Yeah it actually got me motivated to try and trigger EGR through MS2 under very specific conditions. Without EGR I can only lean it out to a little past 16 before lean surge. With EGR turned on I've taken it to about 17 so far, no lean surge yet. This is NOT a lean burn any by any standard.

Cool!!!

What vehicle do you have and what mods have you done to it.

Its nice to see another lean burn person on here!!!

[dieselbenz]

Its a Mercedes inline 6 that was originally equipped with Kjet mechanical injection. The main thrust of the project was to get rid of Kjet and get some more power out of it but there are some FE benefits to be had as well.
http://img.photobucket.com/albums/v2...g?t=1295767505
Its a work in progress. I had all the EGR plumbing in place so I started looking around to see if I could do anything useful with it and I found this article. The other thing I noticed is if EGR is ON during overrun (in gear, throttle closed, injectors off, above 1300rpm) there is a lot less engine braking. I'm thinking of setting the EGR trigger through the brake light circuit so it turns off when you use the brakes. Engine braking on demand. I'm doing something similar with the ICV where it switches to 100% duty cycle when the throttle is wide open. Try to squeeze a little more air flow through the manifold.
Anyway, its a 5 speed manual 190e, still running stock electronic ignition. MS runs the injectors, ICV, EGR and cooling fans.

[pgfpro]

Originally Posted by tjts1

Its a Mercedes inline 6 that was originally equipped with Kjet mechanical injection. The main thrust of the project was to get rid of Kjet and get some more power out of it but there are some FE benefits to be had as well.
http://img.photobucket.com/albums/v2...g?t=1295767505
Its a work in progress. I had all the EGR plumbing in place so I started looking around to see if I could do anything useful with it and I found this article. The other thing I noticed is if EGR is ON during overrun (in gear, throttle closed, injectors off, above 1300rpm) there is a lot less engine braking. I'm thinking of setting the EGR trigger through the brake light circuit so it turns off when you use the brakes. Engine braking on demand. I'm doing something similar with the ICV where it switches to 100% duty cycle when the throttle is wide open. Try to squeeze a little more air flow through the manifold.
Anyway, its a 5 speed manual 190e, still running stock electronic ignition. MS runs the injectors, ICV, EGR and cooling fans.

Nice project!!!

I might have to experiment with your EGR turning on during over run. I have a huge problem with my Talon every time I let off the gas. The Talon engine-brakes way more then I want. So I have been putting it in neutral to try to over come this problem.

Good info. Thanks!!!

[dieselbenz]

If you have full authority over your engine management and fuel cut is governed by the TPS, in theory, you should be be able to switch the EGR and ICV to fully open to help collapse the manifold vacuum. The idea is the same as EGR during low load condition. The closer you can bring manifold pressure to atmospheric pressure, the less pumping loss you'll have. Some people try to accomplish this by switching off the injectors manually while holding the throttle plate open. It doesn't seem like a very practical solution in the real world but I've never tried that method. I want to keep it as seamless to the driver as possible.
cheers