Air / Fuel Meter Recommendations

[AK260]

After seeing this thread earlier in the week I ordered an AEM wideband AFM, as I had the exhaust off the car. looks like I need to mess with my floats a bit. [emoji51]

Good job. In my books, it is the ONLY way to properly home tune your car and half the price of a rolling road. IMHO even better than RR as you see what the afr is doing in the real world under real driving conditions!

I also installed mine into the glove box, but with long cables so that I could pull it out and stick it on the windscreen when I use it.

[heyitsrama]

27 minutes ago, AK260 said:

 

 

Good job. In my books, it is the ONLY way to properly home tune your car and half the price of a rolling road. IMHO even better than RR as you see what the afr is doing in the real world under real driving conditions!

I also installed mine into the glove box, but with long cables so that I could pull it out and stick it on the windscreen when I use it.

 

 

Howd you get the mount to stick while driving? Magnet? Surprisingly it was straight forward to weld the bung onto the exhaust, I really wanted to avoid the welds looking like complete 💩. After reading the instruction you don’t want to do what I did and install the o2 in a complete vertical position, it’s recommended to keep tilted to avoid it getting too hot (from the installation instructions that I read after installing). I’m not sure how problematic this is, I installed the o2 about an 2in after the two pipes meet. 

I got the ESP8266 broadcasting a wifi signal, next step is figuring out a way to have it output a data stream

 

Edited November 28, 2020 by heyitsrama

[jonbill]

On 11/26/2020 at 2:44 AM, Captain Obvious said:

@Jeff Berk I did a little digging into the heating element and how it's used. My (admittedly limited) research indicates that you are correct if you're talking about the older O2 sensors which would run the heating element all the time, but the new ones are monitored and modulated by the engine computer.

In order to achieve A/F sensor accuracy, they want the sensor to stay at a constant temperature at all time, so they modulate the power sent to the heater to keep the temp constant. Older sensors didn't need that level of control, they just need to be really hot, but the newer wide band sensors need to stay at a constant temp.

Here's the best article I could find about the whole thing:

https://www.autoserviceprofessional.com/articles/1097-oxygen-sensor-heaters-how-do-you-know-if-that-heater-fault-code-is-real

I can vouch for the importance of heater control. I swapped out my wideband controller yesterday from an old Prosport one to a 14point7 one. The prosport one would jitter around 13.8 to 14.5 at idle whereas the new one only varies by 0.1 or 0.2. I understand this is because the new one controls the temperature much more accurately. 

[AK260]

Howd you get the mount to stick while driving? Magnet?

I have a magnetic windscreen mobile phone mount but ironically I don’t use the magnet, the flexible but firm shaft from the suction cup to the magnet wraps around the gauge and holds it in place firmly.

It’s like this one ...



I found that a real-time view of AFR v what my right foot was doing was very valuable in learning what the carbs were doing at any given point. But anything other than in my line of sight, was making me take my eyes off the road too often and for too long. If I had a proper data logger I probably would leave it hidden and periodically, just pull over to play on a laptop.

[AK260]

Here it is in situ

[Captain Obvious]

Thanks for all the input guys. I was thinking I would put mine in the glovebox for now as well. I'm still hoping to get a couple weeks more driving out of my car before the season ends though. I don't want to go dropping the exhaust now. It won't be long before they salt the roads and I'll do some of this work then.

[Captain Obvious]

14 hours ago, heyitsrama said:

Which microcontroller were you planning to use? I got a few ESP8266 that were intended for a different project.

LOL. I was just thinking that if I really got into it, I could probably program something up to control the heating element for the sensor. But I got bigger fish to fry first. Plenty of other projects in the way before I would get to that point in my list.  Haha!

I've never messed with the ESP8266 stuff. I've got just enough experience with PICAxe and Arduino stuff to be dangerous. The ESP board is way more powerful than anything I've needed so far.

[SteveJ]

I have to stop reading threads like this. Now I'm considering getting an AFR with a wideband and a 4 channel data logger. I could probably rig up the sender on my fuel pressure gauge to give me a signal, and I can tap into the TPS.

ARGH! You guys are evil. I don't need to go down this path, but now I WANT to!

[Captain Obvious]

You know Z wants it.

[heyitsrama]

Does anyone have a AFR vs RPM graph i can take a look at? I got it down to a 12.5-13 on idle, 15-16 at cruising speed on the highway, and 11 WOT. 700rpm idle. It's much easier to stand behind the car now, and you dont wreak of gas after a drive. I think the cruising speed levels are kinda high, and the idle is a bit too low. I think i finally got my 4 screw SU down to the 23mm on both front and rear carbs, might need to mess with the screw and the idle settings now.

 

[Captain Obvious]

9 hours ago, heyitsrama said:

Does anyone have a AFR vs RPM graph i can take a look at?

There are several graphs like that in @blodi thread where he's trying to tune his Webers:
https://www.classiczcars.com/forums/topic/56375-weber-selection-and-initial-jet-tuning/

I don't know how applicable his Weber graphs would be to your round tops, but for example, they look like this:

[Captain Obvious]

So I got a question about my new A/F meter... Can I stick the O2 sensor up the tailpipe and use it like that for a couple minutes? Instead of welding a bung in?

I mean, I wouldn't expect it to be as accurate if I used it the way it's supposed to be used and had the sensor installed way up by the engine, but just to test things out and see if it works? Cool sounding idea? Bad idea? Dangerous idea?