MTX-L vs LC-2
 

Might be a stupid question, but why would you get the LC-2 over the MTX-L? I mean, if I didn't want the gauge, I could just hide it somewhere. They cost pretty much the same.

Thanks,
--Ferdi

I didn't want the LED gauge in my dash but I wanted something so I picked up both of these: G3 Gauges: Air Fuel Ratio Guage

To be honest though I never look at it. I'm usually focused on driving.

The wideband functionality is the same. The difference is packaging/cosmetics. I have both in stock if you want to see them.

I got the LC-2 because its compact dimensions allow for easier packaging. I didn't want a AFR gauge in my dash vent because in my experience they were of limited utility and another distraction. I'd rather have my virtual gauge cluster when tuning so I can see more than just AFR and a big red idiot light to warn me when something is way out of whack all other times.

I have both. :burncash:

As Ben said, the electronics are exactly the same on the "business" end of things. The MTX-L requires you to stick the gauge... somewhere. Its nice because its an all-in-one package but you are stuck with the gauge if you want it or not. I didn't like it in the Miata because it didn't match anything else in my interior, but its perfect for my truck where IDGAF.

I bought the LC-2 specifically because it does not include a gauge and I planned on using something else (VEI in this case.)

I'm not confident enough to not have a gauge somewhere, but that's completely up to the end user. In addition to the above, I've also owned and used the AEM UEGO, and worked with an AEM FailSafe WB/Boost gauge. All 4 seem to work just fine, so pick one that has the features you like and roll with it.

If you have any specific questions about any of the above, ask away and I'll see if I can help :bigtu:

I put mine in the glovebox:

https://www.miataturbo.net/attachmen...ine=1374483757

https://www.miataturbo.net/attachmen...ine=1375669681

The electronics are not "the same".

The LC2 has the advantage of having a separate output signal ground. Gives you more flexibility in wiring to have more accurate readings, but also more rope to hang yourself with.

EDIT: LC1 not LC2 has separate grounds.

Huh, I hadn't realized that. Jason: I believe this has been your main gripe about most of the widebands on the market, correct?

I believe I have my sensor ground for the LC-2 attached directly to the block. Seemed like the right thing to do at the time.

Negative. The LC2 is a 4 wire hookup:
power (switched)
consolidated ground
analog out 1
analog out 2

Users who felt that having multiple ground wires was "too difficult" to hook up killed divorced grounds.

Ya'll gonna go make me check my LC-2 now. I could have sworn it had 2 grounds. Maybe I'm thinking of something else?

LC-1 has two grounds, LC-2 has one.

At least, according to the install guides...

The 6 wire or the 7 wire LC-1? :giggle:

At least two? :loser:

:giggle:

OK I got confused. I was thinking about the LC-1 which has a separate signal output ground. The LC-2 has a single ground, like the MTX-L.

Yes about gripe.

Grounding at block: Big mistake. If you only have a single ground and are using an analog output, you should terminate it at a POWER GROUND pin very close to the ECU.

More specifically - very close to the ECU's ground point, not the ECU mounting location.

Sooo confusing.

The ECU grounding point is on the head, which is attached to the block?

I just ran mine like the manual, straight to the battery...

Hurry up serial to CAN adapter...

Exactly. I love that damn thing more than I care to admit.

NO. Terminate the wideband's ground wire at a wire that connects to the ECU POWER GROUND PIN, at a location very close to (inches away) the connector that plugs into the ECU box itself. DO NOT connect it far from the ECU itself. Do not think "Oh the ECU is grounded to the block so I'll ground the wideband to the same lug at the block".

And don't shorten the LC2 or MTX-L cable. I suspect they perform "cable drop compensation" which compensates for the error coming from the length of the cable. If you change the length the compensation will become wrong and the analog signal will be corrupted.

If you have an LC1 which has a separate analog and power ground, you electrically terminate the analog ground wire to the ECU's analog ground wire. Exact physical location is less critical. You can physically terminate it close to the ECU connector's signal gnd pin, or to a shared wire which goes to the various sensor grounds in the engine bay. The best connection for the wideband power ground wire is to terminate it on the engine block or head. I can go to the same lug on the engine block or head that the ECU power ground wire goes to, or another point on the engine block or head. This way the heater current which switches on and off, doesn't flow along the ground wire of the ECU.

The concept of "best ground is at the battery negative terminal" is garbage written by people who don't understand circuits and grounding very well.

Thank you for explaining this. I've read several places about the ground location for wideband being critical but never really found the explanation as to why. Now I understand. Sounds like just avoiding voltage drops across long leads of thin gauge wire. By installing the ground close to the ECU (on the ecu's ground wire) and not cutting the ground short, you will get the voltage drop the wideband is calibrated for.