I tried setting my controller step size to 1 the other day to go closed loop, but I didn't like how it ran at all. I'm pretty happy with my open loop tune, and 22 mpg is good enough for me so far, but I wondered where others are at, or problems encountered. A guy at work said he had similar experience on his race RX-7, and decided not to mess with closed loop either. I went back to a NB sensor once I was pretty happy with the tune, so correct me if I'm wrong - To use closed loop, I would pretty much have to adjust my VE to get me around 14.7:1 in all areas under my open loop threshold, which is 80 Kpa so that it doesn't have to adjust very much to keep it there, right? Currently I have the VE set so that I am somewhat lean at cruising, rich in a lot of other places that I like to hang out, : ) but I would guess that it doesn't like to bring me back to 14.7 when I'm far way from it, so it bounces around too much?

 

I've never liked closed loop. I always got too much hunting. My VE is pretty dialed in, too. I wouldn't reccomend using it with a narrow sensor. 14.7 is really not good for anything, cept emissions. 16-16.5:1 for cruise and 11:1 for accel. I haven't even used autotune. I just find it quicker and more straightforward to change it myself.

 

That's good to hear. I am running WB only when I want to tune, because I built the DIY WB kit that uses the expensive sensor and they say if I don't let it warm up for 30 seconds before I start it, it damages the sensor. So then when I don't have the WB sensor in, there's no reason at all to have a NB O2 sensor in, right?

 

I'm running open loop but I'm not using the standard 029q2 or r or what-ever it is now. I'm running keithmac's ignition controlled idle code version of MSnSE and I'm really happy with the idle on my car.

 

Is that just open loop at idle, and the into closed loop at cruise? or is that open loop permanently?

Just wondering if people report better or worse consumption because of running open all the time. I know the MX5/Miata runs pig rich standard above 4k as it's in open loop.

I notice that Fulltilt said he's getting 22mpg, that's pretty shocking in my book?!?

 

For running, I'm running open loop at the higher rpm and map bins. From memory it's over 70 kpa.

 

I have thought it better to err on the rich side. I'm sure I could do much better, but I don't drive it enough to mind the price I pay for gas. I have heard some of these guys getting much better mileage.

 

in my stock '97 I quite frequently get 22 - 23 mpg. But I drive delivery with that car and do so w/ gusto. My driving style must be terrible for gas mileage because with my last 2 cars prior both got worse mileage than most of what was reported on their online forums.

Umm sorry I got off topic ... but I dont really understand why there is a problem tuning closed loop? Is it hard to get the handover smooth, something to do with the tps on/off switch, or what?

 

If your tune is nicely worked over... you probably never need the o2 correct. I run my daily driver with it off and get over 30mpg... 1.6L turbo honda.

But I run a wideband fulltime in the car... so I can see if the weather(temp/humidity/UFOs ) causes problems with the tune.