Hondata

Hondata,

I have been using K-Pro for the past 3 years and I love the product. I have recently become more interested in tuning the car to run a little leaner under cruising conditions. I have noticed that the auto adjustment when in closed loop will automatically set to adjust your fuel to 14.7. With gas the way it is (or was thx to our economy :lol:) I am trying to run a part throttle lean condition of 16.0:1 A/F. I was wondering if it was possible to add the option to change the point at which the computer adjusts the fuel in closed loop. This would make tuning during constant temperature changes MUCH easier and more consistent. I had my tune running pretty good during the summer months, however during these recent colder days I have had gas mileage fluctuate almost 7mpg. I've tried messing with temperature compensation but it just seems too sensitive to the smallest changes. Varying Auto adjustment here would be a WONDERFUL addition to K-Pro and I was wondering if it was possible to do?

Thanks,

Stwatson

Not at the moment. There are emission issues when running leaner than 14.7.

Since kpro is "For off-road use only" maybe u guys can give us the option to change it without having to keep the car in Open Loop tuned lower then 14.7.

drumnatural wrote:Since kpro is "For off-road use only" maybe u guys can give us the option to change it without having to keep the car in Open Loop tuned lower then 14.7.

I agree, it would be a very nice asset as I run a 16.5 in cruise and weather can affect it a good bit and sometimes you can end up having worse than stock MPG lol

So...is there NO chance for this to happen? I understand there are emission issues but as its already been stated this is for "off road use". I just need to have the best gas mileage possible from the staging lanes to the tree at the strip :D

Are there any chances?

Been asking for this feature in Kpro for a while. Seems like we almost had a breakthrough a couple of versions ago when there was actually a "closed loop target lambda" included in the .kal files, but maybe not?

It can be set up externally to Kpro, but some wiring is involved. Basically you need to build an isolated, somewhat regulated and adjustable DC power supply of about 1.5V / 20mA maximum. Hook this in parallel to your oxygen sensor + and - leads from the ECU. You then adjust the DC supply so your ECU 'thinks' it's running rich. The ECU response is then to lean out the mix to what it thinks is stoic, but what in reality is a little leaner. But, you're still in closed loop, so the ECU will actively maintain this lean mix.

To get really fancy, hook up a relay to operate off one of the Kpro nitrous controls. You have your circuit cut out and run stoic for all idle, shifting, 'round town, stop-n-go type stuff where drivability is an issue. But set the nitrous parameters to kick in from say 1500-3300 rpm, 40-75 mph, 5-25% throttle - which is pretty much light throttle, steady state cruising, and you can get a couple extra mpg or so.

The downside is that once you engage your circuit, the O2 sensor reading in Kpro is off, because you are actually fooling the numbers the computer is reading. You can look at a datalog and see what the values jump to immediately after you shut off the circuit. That gives a pretty good idea of what AFR you're running with the circuit on. Secondly, since there is no coolant temp parameter in the nitrous, you can get into your lean burn parameters with a cold engine which may cause a bit of stumbling.

I've made a more extensive post of this with data logs of it in action here:
http://e85vehicles.com/e85/index.php/topic,1586.0.html


So if you're looking for the summary:

Closed loop AFR control through Kpro would be cool, though can be done now with external hardware.

Ideally, it would be tied to work through something similar to a nitrous control so a 'lean burn' could be initiated under light throttle cruising, but stoic could be maintained for most other driving and, of course, open loop for high engine loads.

A temperature parameter would be nice for AFR (as well as nitrous control) Don't like running lean (or hitting nitrous) when the engine is cold!

I too would really appreciate this feature.

Although there probably isn't enough room on the ecu to do so, it would be really nice to have a "target A/F Ratio table" This way we could easily set the target A/R to different values at different speed/loads.

Please *_*