My Stock 2003's AFR vs RPM Graphs

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Tonight I decided to go play with my FJO Wideband on my Cobra. It datalogs to my Laptop. Here are the graphs of two seperate pulls. Both done within 15 min. of one another. Unfortunately I couldn't get a 4th gear run for safety reasons.

 

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2nd run:

 

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I meant to add in that these logs were done AFTER the cats using the driver's side rear O2 bung. I've seen about a .1 to .3 difference on the Lightnings when I have tested them this way.

Unfortunately, I may not be able to test the difference between measuring at the front O2's or rear O2's, as the factory calibration is already so pig rich it barely registers over 4500. I may have to wait till when I reprogram the factory calibration to do this test.

 

[Jon]

Looks pretty typical: lean in the midrange and rich up top.

Are you going to chip it?

 

[highmiles]

!

 

[highmiles]

!

 

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Originally posted by highmiles
Do you leave the system attached to your car regularly or just when testing?
I was just wondering the value of the kit, if you think it was worth the money?
Did you get the display and rpm attachment?
Any photos of of your install.

Actually, I use it to tune and test other vehicles, so I will not mount this one permanently to my Cobra, but I may, in the future, buy an additional unit specifically just for it only.

Yes, the FJO is very much worth the money. If you ever purchase it, go through Steven Hayes at www.widebandO2.com as I found him to have the best in pricing. Not advertising for him, just the best service and support and pricing that I have found.

My setup consists of the green led display, and the datalogging kit for my laptop. I rarely use the display anymore and normally just log all of the vehicles I test so I can have a graph like above to rely on when tuning.

02 Sensors:
Stock 3-4 wires
FJO 5 wires
Dynojet 6 wires

How accurate is the FJO, will the FJO datalogged A/F curve match the Dynojet A/F curve after doing a dyno pull?
What is the sampling intervals on the loggers?
Any better altenatives to FJO?

It is the most accurate wideband that I've ever tested. Dynojet's a/f readings are typically showing "leaner" than what a real wideband will read in front of the cats. If you have off roads then this really isn't an issue. The Dynojet's a/f meter is decent, but it isn't the best.

The FJO will sample as fast as the vehicle can spit out data. It's instantaneous to the most minute of charges in the vehicle's throttle. Here's some specs on it:

The FJO Wide Band Oxygen Sensor Controller utilizes a 5 wire oxygen sensor with an integrated 2 wire calibration resistor to obtain accurate air/fuel mixture readings from 10:1 to 20:1 AFR. The controller features both an analog and a digital output which may be connected to the 341B Engine Management System, Monitor Display, AFR Display or to the serial port of any laptop computer. Following the practice of all other FJO products, the controller is designed with a rugged chassis and features environmentally sealed Weather-Pack connectors.

Specifications:
- sensing range: 10:1 to 20:1 AFR (gasoline)
- accuracy: better than 0.1 AFR over the range 10.5:1 to 15.5:1
- dimensions: 139 mm x 61 mm x 32 mm
- weight: 450 g
- power: 12 volts DC
- auxiliary analog input: 0-5 volts (high impedance)
- RPM input: 10,000 rpm maximum (using optional FJO RPM pickup)
- analog output: 0-5 volt high impedance
- digital output: RS232C at 19200 baud
- temperature range: -40 to +85 ºC ambient

If anyone wants to learn more about it go to www.fjoinc.com/automotive