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Logging Wideband O2 Via The TGV Sensor Input


Turkeylord

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On the other hand, if you can get the WBO2 to match the stock sensor at idle and read what the manufacturer expects when you lift the throttle (16:1 or 20:1 or whatever) that should be enough to get the multiplier and offset correct. Since it's a linear equation, two points should be all you need. That said, the further apart your known values are, the better.

I tried this also, it doesn't work. Although there is an upper bounds of 18 on the gauge, because the injectors are shut off, there really is no upper bounds. The stock O2 will read 20.03, The AEM gauge reads 18, my old LC1 read 23. Again, the problem with matching it to the stock o2 is the slow response of the stock o2. It doesn't pick up small fluctuations.

 

Turkeylord- are you seeing a full 5 volts when you lift off throttle? Mine only goes to 4.18 on the AP and RR. The upper bound on the logger with my formula is 17.54. I thought something was wrong but all my logs match the AEM logger.

 

And FWIW, my AEM is at the beginning of my catback. I was getting overheating codes with my LC1 in the down pipe so I moved the AEM to an extra spot on my catback. No problems at all.

Edited by bnguyenbb6
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from what I've heard/read, it's more about protecting the side of the sensor that's not in the exhaust from heat, so it's not a heatsink, it's more of a heatshield. deflects heat from the exhaust pipe away from the sensor. either wrap, coat, or add a little round heatshield (washer) under the WB02.

 

Edit for clarity, the "washer" shouldn't/doesn't need to be thick (no fender washers). just drill a hole for the O2 sensor in some thin steel and then cut the outer edges to your preferred geometric shape. round just sounds less likely to cut/poke any electricals or hands.

 

A very easy and cheap way to make a copper heatshield is to go to a home improvement store and buy a small section of 1" ID copper pipe and then cut, fold and drill the hole for the sensor.

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Keep in mind that AEM is assuming that the turbo is located just inches from the exhaust ports, because most turbos are mounted right at the exhaust manifold's collector. Subaru turbos are two or three feet downstream of the exhaust ports, so most of us put our WBO2 into bungs that are right on the bellmouth.

 

This!

- Pro amore Dei et patriam et populum -
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2 things, first is i heard that on 07+ uses tumbling more than at idle. Second, while it sounds redic, could one just remove the plugs and the CELs and leave the valves, motors and sensors in place? Will they stay open if unplugged?

 

Sent from my XT1028

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I'm currently installing an LC-2 right now and looking for a good place to tap for electrical power. It's important to find a source that only powers in the ON position of the ignition switch. The O2 sensor can apparently overheat if no exhaust gases are flowing over it? I'm also putting my O2 in the bell mouth (Invidia down pipe). I'm welding in a 1" stainless bung from UEGO that is supposedly a "heat sink" to keep the sensor temperature down. It has fins on it. Probably overkill for that location but I do like the idea of using a 1" in lieu of 1/2" bung. The copper heat shield sounds good too. Also, the second O2 sensor location should only be used if there is no cat in your exhaust before that point. Edited by Saltysubie
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I think that is correct that it is ACC. I ended up running a hot (and ground) back to the battery directly and put in an interposing relay to switch on the hot to the LC-2 using a wire that is powered from an "ignition" circuit. In looking at the FSM, it looked like fuses 5 and 12 on the driver's under dash fuse panel are energized from the "ignition" position of the key. There was a plug coming into the fuse box labeled "h". This plug is fed by one of those fuses (can't remember which one though).

http://images.tapatalk-cdn.com/15/07/22/5a5fead705f0f8da8d9b18400252da3d.jpg

Here's a picture showing the white taped conductors going into a yellow termination. The wire I tapped into was green with a yellow stripe. The FSM said there wasn't supposed to be a wire in this pin. It looks like it may be the wire going back to the fuel pump controller.

http://images.tapatalk-cdn.com/15/07/22/738f88b4c7822d7df57816c7b3c183c2.jpg

Anyways, I tapped this wire just to provide the signal for the relay to power on the LC-2. I mounted the interposing relay behind the driver side kick panel. In the end, I would like to confirm if the sensor is actually a heated one. The power wire to the LC-2 looks like it is only about 22awg. That seems pretty small for a wire that needs to provide electric heating to a sensor, so I'm guessing this is not a heated sensor? EDIT: The LC-2 can use a Bosch LSU-4.2 or LSU-4.9 O2 sensor, both of which are electrically heated sensors. The hot circuit only draws about 3 amps, so the small wire is okay.

 

Looking back into the LC-2 instructions, it looks like it is only a 5 amp fused requirement and they say it is okay to power from either an accessory source or an ignition source - lighter power should be fine. Where I was confused was that the manual also includes this warning:

"Do not pre-warm the sensor before starting the engine, simply start the engine as normal. Allowing the sensor to pre-warm before starting the engine will increase the possibility of damaging the sensor from shock-cooling."

So, I was playing it conservative by switching it on from an ignition circuit. I guess that what they are really saying here is not to put the key in the IGN position and let it sit there before placing it in the START position.

 

I'm going to shut up now because I'm kind of getting off topic....

Edited by Saltysubie
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  • 6 months later...

Oh, for others interested in more than 2 inputs, get an 08+ gen 4 LGT or gen 3 OBXT.

 

ECU Air pump pressure sensor input FTW.

 

Not that I've attempted it, but I can't imagine that with an air pump delete (KSTech plates are cheap and it's simple to do yourself) that you couldn't hijack the ECU input just like the TGV sensors.

 

hmm...cept I'm not sure there's a romraider logging parameter...

 

*goes off to do more research*

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  • 3 weeks later...

So if I'm understanding correctly, you solder/stick the output wires from o2 sensor/oil pressure sensor/new fun engine monitoring sensor into that linked connector, then plug directly into TGV wiring connection on the engine harness?

 

omgdnss that's getting added to the list.

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So if I'm understanding correctly, you solder/stick the output wires from o2 sensor/oil pressure sensor/new fun engine monitoring sensor into that linked connector, then plug directly into TGV wiring connection on the engine harness?

 

omgdnss that's getting added to the list.

0-5v sensors, and i don't believe you can power it from the tgv connector (would need to look at the vaca pics), but yes.

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If you try to power something from the TGV connector I'm pretty sure you could very easily fry something in the ECU.

 

The TGV sensor connector was only intended to provide a tiny amount of current, so the traces on the circuit board are probably correspondingly tiny, and so is every component in the chain from the 5v regulator to that connector. And if I'm wrong about that stuff, then you might just fry the regulator itself instead.

 

WBO2 sensors have a heating element that will draw a lot of power. Plus they need 12 volts which makes this a non-starter anyway. :)

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  • 2 weeks later...
Today I purchased what I think is a plug and play solution to the tgv female connector for a clean install. I believe turkeylord discovered this a while ago. I will report back once this arrives and whether it actually fits.

 

http://www.bmotorsports.com/shop/product_info.php/cPath/109_110/products_id/2107

 

Did they fit?

 

I'm itching to make a wiring harness, and these would be great... if they fit. :)

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  • 1 month later...
Unfortunately, no. Back to the drawing board for me too.

 

 

Bummer. Thanks for trying, though!

 

I know I said it wouldn't but now I change my mind...

 

I modeled my own 3 prong connector using autodesk inventor and then printed a rough draft. I then compared the purchased version to my printed version and to my actual tgv sensor. The overall dimensions are nearly identical but the actual tgv has a few more "bells and whistles" on the exterior.

 

How does one get the purchased version to fit? It's really simple; it's so stupid that I didn't notice it before. You just cut one little part off of the bottom and then the connector will fit right in! Unfortunately it will not "snap" into place due to the previously mentioned "bells and whistles". The connector is snug though and doesn't appear as if it will magically dosconnect.

 

Picture for proof:

 

http://uploads.tapatalk-cdn.com/20160420/06c7e3704280ad68647d9bf0fe5cf908.jpg

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