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View Full Version : emanage blue+wideband o2=best map clamp EVER!! - By sour kraut

11-02-2019, 07:44 PM
This is mainly technical so if you don't understand it sorry.


If you have a wideband o2 with a linear output and the blue emanage, you can make the emanage tune itself using the wideband and have it run as if stock in closed loop operation.

Some of you are already getting the bs flag out but let me explain this first. If you connect the wideband's output to the throttle in on your emanage, you effectively are tuning by your a/f ratios. You set your 0% throttle to 0.00 volts and your 100% throttle to exactly double the voltage of the desired a/f ratio. So if you want a 11.5/1 at wot and the voltage for that is .75, you set 0% to ground and 100% to 1.50 volts. This will make your desired a/f ratio become 50% throttle. Now before anyone yells about closed loop wanting 14.7/1, let me finish.

You need to build a small circuit that shows the emanage 50% throttle while in closed loop and the actual wideband voltage while in open loop. What a dilemma! You have a couple of diffrent choices on how to do this, but I deceided on using 91CavGT's PTB as a begining. I used a hobbs switch to cause the car to go into open loop by showing the pcm 100% throttle as soon as a preset boost level is reached. This is where my design veries from his. I have the hobbs controlling a relay that passes the original tps signal to the computer until the preset boost level, after that It shows the pcm 3.81 volts until the boost drops back down below the preset level. The hobbs is also switching another relay at the same time that shows the emanage the correct voltage for 50% throttle under the preset boost level, and the actual wideband output above this.Being the nice guy that I am, I will share the schematics with you.


Sorry if its kinda small.I'm not the best at drawing schematics so if anyone else can redraw them more user friendly please do and post them up.

Ok, here's how it works. 12 volt and ground are easy enough to understand and find in the car.The 12 volt is supplied to the hobbs and then returned to the board to energize the relays causing them to go from the normally closed to the normally opened position, easy enough. The 12 volts and ground are also supplied to 2 diffrent 5 volt regulators. These regulators put out almost exactly 5.00 volts(or close enough not to make a diffrence).
One of these regulators is feeding a voltage divider that is tapped into to supply the 3.81 volts to fool the computer into going into open loop. This voltage is connected to the normally open contact on the relay while the actual tps signal is connected to the normally closed. You do have to cut the tps wire and run it to this circuit as you would the map for the emanage.

The other 5 volt regulator is run through a current limiting resistor to a pot. the pot's center tap is running to another voltage divider. At the center of this divider is the voltage equal to your desired a/f ratio voltage. At the top is the voltage equal to your 100% throttle you have to show the emanage. At the bottom of this is ground, which is your 0% throttle voltage you need to show the emanage. The 2 switches allow you to be able to show the emanage your 100% and 0% easily during throttle setup. The voltage from the center tap of this voltage divider is feed through these switches to the normally closed contact on the second relay while the o2 output is feed to the normally open. The common on these is feed to the emanage throttle input.

Easy enough huh?

Now that we have the circuit built, tested, and know that everthing is working as should(I inserted another switch on the original to bypass the hobbs for testing which is not on the schematic), it's time to move on to the maps you need set. I am only using the airflow adjustment map because it affords me a safty. If I cannot supply enough fuel for my settings the emanage adds map voltage causing the pcm to retard timing and saving the motor (http://www.srtforums.com/forums/showthread.php?t=158399#) from knock. Once again, here is a screen shot of my map so you can get somewhat of an understanding of what it is doing.


If you noticed I have 49% and 51% at zero also and was wondering why,here's the explination on this. Because the circuit is very low tech, temperature will affect the preset voltage enough for the emanage to swing between 51% and 49% and we don't want it to try to correct fuel in closed loop because of temperature fluctuations.

You'll also notice that anything above 51% is a positive number. this is saying the a/f ratio is leaner then what we want, so we add map voltage. The opposite is also true, anything below 49% is a negative, saying we're too rich, remove map voltage. The benifit of this is, If you can control your fuel pressure (http://www.srtforums.com/forums/showthread.php?t=158399#) using something like the vortech sfmu, you can control the voltage the emanage sends out on the map wire. Basicly, you are building a VERY proactive map clamp.

Now, If you cannot supply enough fuel, UPGRADE your fuel supply before trying anything like this. If you can supply enough fuel, you may see a problem with a fluctuation in your a/f ratio, I've seen 2 diffrent causes for this while testing. Cause 1; your boost is fluctuating, usually 5psi or more. Cause 2; Water injection is causing the boost to fluctuate too much, it took me 2 days to figure this one out.

I hope I have explained everything well enough for you, the reader, to understand the concept here. If not, here are the cliff notes: Easily tune the a/f ratio you want by turning a pot and resetting throttle %'s. Pertection if you cannot supply enough fuel. Proactive map clamp if you can control fuel delivery.

I cannot claim this to be my idea, someone on the yahoo emanage group is selling something very similar to this, I just figured out how to make it srt4 specific. If you have any questions, PLEASE, reread the post before pm'ing me. Everything used to build the circuit can be found at a local radioshack and the hobbs at napa.

I have successfully been running this setup for over 2 weeks with no real problems except the fluctuating boost levels caused by the h2o and since those were corrected, no problems at all.

12-02-2019, 04:13 PM
Has anyone in the Chicagoland area done this? I'd like to see it in person and perhaps create one for myself. :thumb:

12-03-2019, 11:55 AM
Has anyone in the Chicagoland area done this? I'd like to see it in person and perhaps create one for myself. :thumb:

well sourkrout is one of our indy club members, so if you wanna see it you can come down to one of our meets, you can also join indianasrt.com if you wanna discuss it with him more