Yet Another CRX HF

[SVOboy]

Lean burn is much more than just leaning out the AFRs a bit. A few have tried, I set krousdb up with a slightly leaned ecu, and he saw no benefit to it. There is an article I posted on here somewhere where a group of guys tuned an rsx on a dyno for FE and gained 2% with AFR tweaks and timing changes. I am set up to all this, but haven't bothered, as I don't see the gains worth the effort and the near impossibility to test. *shrug*

[koffin]

To my surprise, not many tune here.
I too would scrap the megasquirt and just convert to obd1 with a chipped ECU.

www.xenocron.com is a GREAT resource for DIY needs. I bought my Moates equipment, wideband and other tuning tools from him. He also supports everything he sells to the fullest.

check out www.pgmfi.org. Read, read and read some more. This is the site when it comes to obd1 Honda tuning. When you are done practicing on the CRX, step up to you your GSR!

With all due respect to SVOboy, I do believe there are gains to be had by leaning out the AFR. He is right though, AFRs are only part of it. There is much more to it.
We have an abundance of E85 up here in the grain belt. It runs "cooler" and will allow me to lean it out even more-so than gasoline.

Now, if I can just find the time........

If you have some questions about tuning and/or xenoncron, let me know. I'll do what I can. Welcome.

[MetroMPG]

One reason I don't want to tinker with AFR is because I understand it will raise NOX emissions.

[mrmad]

I've read the RSX article and was curious as to why they picked an RSX. Considering it has a relatively high CR, is tuned for high rpms, and has very short gearing, I wonder if the results would have been different had they selected a Metro or CRX. In theory, the difference betwen 14.7 and 16 AFR is 8.125% less gas. Of course reality would likely be less, or your mileage may vary.

As the AFR gets higher then 14.7, the hydrocarbon emissions decrease and the NOX emissions increase. Not happy about the increased NOX, but to keep things in perspective, the CA emissions tests measure in % (in ppm), not in the total amount of pollutants emitted. I would imagine that a lean burning CRX at 2100 rpms is still emitting alot less NOX then some big V8 that just left the smog station.

[MetroMPG]

True, but regardless of what the other cars on the road are doing, it's still emitting more NOX than it was before the mod. That's what holds me back.

[koffin]

You guys have it rough. We don't have vehicle inspections in Mn.
That being said, I feel better leaning out a renewable fuel source.

[cfg83]

MetroMPG -

Originally Posted by MetroMPG

One reason I don't want to tinker with AFR is because I understand it will raise NOX emissions.

I agree. When I was a kid in LA in the 1970's (near the cleaner beach air!) I remember choking on the air. Even though there are more cars in LA today, the improved emissions are such that I don't feel that smog-alert air like I used to.

My longterm goal is to do a "clean" lean-burn in the sense that I want to go as far as I can into lean-burn but still be California emissions compliant. When I am ready, I will use my mechanic's smog equipment for that. If I succeed, I will most probably emit more NOx, but I should be borderline compliant for the car I am driving.

What do you think of the WAI/HAI? I think it's a "clean" way of moving closer to lean-burn because for some drivetrains, you are "pushing" the ECU/PCM to decide to go into a lean-burn mode.

CarloSW2

[mrmad]

"What do you think of the WAI/HAI? I think it's a "clean" way of moving closer to lean-burn because for some drivetrains, you are "pushing" the ECU/PCM to decide to go into a lean-burn mode."

Not sure what you mean here. Isn't anything that leans the AFR beyond the stiochiometric ratio, whether it is a WAI/HAI or a reprogrammed ECU, going to raise the NOx emissions?

[SVOboy]

The HAI/WAI does not create a lean condition, it simply reduces oxygen content by collecting a hotter intake charge.

[cfg83]

SVOboy -

Originally Posted by SVOboy

The HAI/WAI does not create a lean condition, it simply reduces oxygen content by collecting a hotter intake charge.

Ok. I must have misunderstood what I have read here and elsewhere. I have read that things like the IAT mod that simulated HAI temperatures were causing the ECU/PCM to put less fuel in the injectors and thereby invoking lean-burn states. But it's more complicated than that, right ?

CarloSW2