Nerdy engineering/theory discussion on EGR/lean burn
 

I guess i am in kind of a unique position. Ive always been a honda guy, more so as daily beater cars and transportation than hot rodding. But i do have a good deal of tuning knowledge and experience, have some good friends in the "power" industry with dyno access and what not. BUT...with OBD1 hondas (92-95 civic specifically) that i know many of you have, you basically have full control over the ECU programming with the right parts. so my main questions here...

1. EGR. i know its an emissions device, but has anyone thought of implenting it ON 100% of the time during cruise with proper fuel and timing adjustment? this would have a similar effect to displacement on demand type of technologies correct me if im wrong. I just recently started messing with my vtec-e d15z1 and cleaned the egr system all out and got it back to working order. the motor isnt installed in a car yet, but this would be nice to mess with even on a non-vtec civic or crx

2. cam timing vs ignition timing. im sure this would take some BMEP charts and some dyno time, but since we can tune these things to small rpm range (say 1800-2200 rpm highway cruising with crx HF gearing) it would be nice to discuss.

3. compression, intake manifold volume, etc. Also thinking of modifying these for optimal effeciency around the highway rpm. i know from an engineering perspective getting an engine to run very well at a narrow rpm is easier than making it more driveable across a broad rpm, so there may be some tricks to be had here

This is also simply from a DIY tuning/hacking/make the best of what you have idea.

Headles, great ideas. I have little mechanical ability, but would be very interested in anything you are trying. I have a 92 VX and a 89 CRX HF. Most of my driving is in the 1000 to 1600 RPM range (35 to 55 MPH). I would be very interested in any torque increases in these RPM ranges.

Egr is only used to reduce emissions and only came on the honda civic vx and hx models from 1992-2000. If there was any benefit honda would have saved time and resources and just put them on all of their models. (They now all come with egr valves to meet ulev emission standards)

Your best option is a vafc air fuel controller and a true wide band sensor to measure air fuel mixture

EGR used to only be used to reduce emissions. Now, they're using it not only to increase partial load mileage, but also power since it allows you to advance ignition timing. Many OEMs have been using it for years now weather its internal or external. Some are even doing cooled external EGR to get higher EGR flow rates.

I like you idea.:thumbup:
I will be testing this also in the near future. I built a hot and cold modified EGR system. I modified my EGR valve so I can double the amount of flow over stock. I will be testing from 14.7:1 A/F to 30:1 lean burn. I will be glad to share all my data with the forum.

http://ecomodder.com/forum/showthrea...els-23234.html
That's a little thing on intake tuning.

You can also use EGR to warm up the engine fast.
http://ecomodder.com/forum/showthrea...ler-29085.html