AFR gauge

[oilteq]

I am doing some rewiring, and I am considering an AFR gauge. Does anyone have experience with one?

 

Do the numbers jump around too much, making it worthless? Is it more sensitive than ears? In other words, does it start showing lean numbers before the engine starts pinging and knocking? Can it alert me to a developing problem?

 

I have a naturally aspirated Duratec and live in the Midwest, where altitude changes are not a concern. I have a Haltech ECU and I will probably not use a MAF sensor. I do not care for another gauge, unless it can warn me that something is wrong. Input from those that have an AFR gauge would be greatly appreciated.

 

Blaine

[IDreamOfChapman]

So, I have one. I have the AEM digital version (that kind of looks analog) and it isn't super jumpy or otherwise hard to read.

 

Mine doesn't ever show lean because the engine is properly tuned and...doesn't run lean or ever knock or ping. But the gauge is very responsive and steady so I am sure it would indicate a lean condition as soon as it was detected. You probably don't need us to tell you relying on an afr gauge to detect lean conditions isn't the right solution. I keep mine around just in case something goes wrong but honestly once your car is properly tuned then it shouldn't be an issue. The reason I installed it was to make sure my car wasn't running dangerously lean. Which, fortunately for me it isn't.

[wemtd]

I have a similar set up as you and ran without the oxygen sensor initially. After I got my wide-band sensor installed (haltech) the engine was much happier being able to operate in closed-loop mode.

So from my perspective it's definitely worth while.

 

p.

[TurboWood]

Personally I don't see the benefit. I have a boost gauge, EGT gauge, and AFR gauge in my Supra. The only one I watch is the tach. It's nice to watch on occasion or to push the peak hold button (GReddy electronic gauges for boost/EGT) to see what it peaked at, but I wouldn't look at it as a safety net. A calibrated knock sensor is the way to go for protection.

 

I have an FJO sensor with digital gauge and it's wired into the AEM standalone ecu. It's more of a novelty than it is a real safety.

 

Regards,

Daniel

[anthonyseven]

I had one and it was very jumpy. I believe the problem was how my exhaust was configured. There just wasn't a good place to mount the lambda sensor.

[oilteq]

Thanks for the input. I think I will go ahead with the gauge. I would not use it for tuning, and would not consider it protection. However, it may give me a warning in much the same way as an oil pressure gauge or temperature gauge. Perhaps it can tell me if my AFR is getting out of shape and I need to retune.

 

By the way, what is an FJO sensor?

 

Blaine

[fastg]

Blaine, why would you not use it for tuning? It's an invaluable tool, it you just going to use it as a pretty flashing light I think your wasting your money.

 

Graham

[boss351]

I have Innovates LC1 setup and its been really useful from tuning to trouble shooting. Nowadays it looks to be the equivalent to their DB gauge.

Edited July 22, 2013 by boss351

[midgetracr]

I have used Wide Band Oxygen Sensors to tune numerous engines. This includes my recent Stalker V6's, 530 HP LS3 V8, USAC Midget engines and Indy Car engines. In my opinion it is the only accurate way to tune AFR on an engine.

 

WBO2's will react in milliseconds. Much faster and more sensitive than you could ever hope to sense manually. By the time you can hear a knock, it may be too late.

 

That said it is only a tool. The magic is in the tuner that is using it. I have used an Innovate LC1 and was pleased with it although mine did not have a display. It fed data into a logging device.

 

If I was in the market for a new unit I would probably purchase an AFX brand unit. About the same $ and a great reputation in the tuner community.

 

Just my opinion.

 

I am unaware of an aftermarket knock sensor that works. If anyone knows of one, please post info. Thanks.

[slomove]

I have the newer Innovate MTX-L wideband meter. This is basically the LC1 packaged in 52 mm dash gage with digital and bargraph display and 2 programmable analog outputs for logging. Last time I looked it was $200 including the probe. Works very well.

[fastg]

I had an Innovate LC1 on my Turbo Miata feeding a Magasquirt and a gauge. I now have a MTX-L in a Triumph TR8. The LC1 has a separate box that you connect the gauge and Megasquirt to. The MTX-L everything is on the gauge. I used it on my Triumph to tune a Holley and a Edlebrock carb, you can setup cruise, part throttle, full throttle and accelerator pump settings. Both carbs came jetted for my motor, what a joke they were not even close. But after tuning they both ran even better than the delivered setting. The gauges are damped, if they displayed real time it would be a blur. A very accurate and useful tool.

 

Graham

[oilteq]

Sorry about my slow response, but I have been working on my car. I should also be writing a build diary, but that takes time away from actually completing the car. Anyway, I plan to connect the laptop to my ECU and log data, including AFR. Then I can change settings based on the data log, rather than trying to tune on the fly. After I am done tuning and the ECU is running in closed loop to maintain AFR, I still want the AFR gauge. Sometimes I wear a belt and suspenders, just to be sure, but the gauge may warn me if my AFR is getting out of shape for some reason. I know I really do not need it, and I really do not need an oil pressure gauge. But since I am far from factory original and I am tuning it myself, I will feel more comfortable with both an AFR gauge and an oil pressure gauge. Again, I appreciate everyone's input on the topic.

 

Blaine