MTX-L or LC-1 Is one better ( or worse )
 

Ok, so nooby here.

Just down paymented on a reverent built mspnp for my 95. And am trying to piece the other needed stuff before it gets here ( few weeks away )

Almost every time I see someone with megasquirt in a miata they are running lc-1 wideband, even though there are tons of options, some even priced about the same. Any reason for this?

I am considering getting the mtx-l, but seems not as many people run it, was wondering if people just go with the known good model, or there is a downside to the wideband-in-a-guage setup. Something like the aem uego had a slower data rate than lc-1?
Have done searching, but the only difference people mention is the lc-1 is basically a wideband in a cable, with an add on gauge if you want it. And the mtx-l all the hardware is inside the gauge.

Mini question, not worth a whole thread: usdm 95 miata with a 1.8, I do not need to add a variable tps because it already has one? Just double checking.

it's my understanding that the mtx l is just the newer version of the lc1/xd16 combo -

mtx l is better - it's the controller and all the parts that you need in 2 pieces all in 1
it's more simple to wire and easy to set up
i don't see any reason to stick w/ lc1 controller/gauge

Looks like I will be going with the mtx-l then.

no, you don't need to not add a non-variable tps because it doesn't not have one

:)

joking aside, your 95 already has one

Mtx-l ftw!!!

The mtxl is much newer and works just fine. If they had both been available years ago no one would be running an lc1.

That's what I wanted to hear.

And thanks for confirming the 95 had vtps.

The MTX-L has a SERIOUS shortcoming compared to the LC-1.
It has only one ground wire. It doesn't have a separate ground wire for the heater from the analog bits.

There is a rule in analog design, that the sensor ground and the high current grounds be connected together at one and only one point - inside the ECU PCB. By making the same connection in side the MTX-L (which has a high current heater, and a sensor output), it will cause you to violate this rule.

The way you then connect it to your system, will cause you to violate the rule in different ways, with varying degrees of severity.

Because the MTX-L ground wire carries a large current, you must connect it to the ECU high current ground pin. Any looseness in this connection, and any voltage drops in the ECU's internal high current ground traces, will contaminate the analog signal from the wideband.

Do not connect it to the head, because then the voltage drops in the hi current wire from the ECU will add further to the contamination.
And for god's sake don't connect it to the sensor ground pin on the ECU, because then the current in the wideband heater will contaminate ALL the senror signals.

Caveat emptor. Thanks, Innovate.

i have 1 wire coming from my ms2 - the wb signal and that's it
all of my gauges are wired independently and do not use any of the power or ground from the ms
it's been that way a while now and i have no issues

Where did you ground your mtx-l?

I remember reading something about grounding close as possible to the ecu with a wideband. To minimize noise from the alternator.

all of my gauges are grounded on the metal behind the dash under one of the pop out tabs - drivers side - in between the dash and the door

i've watched it in tuner studio and on the gauge at the same time while driving and it seems to read exactly the same - iv'e also data logged it and it says exactly what it is at wot

but i'm slowly being convinced to use the ecu's ground...
i guess i'll change it soon

If you can't tell a difference between the two its close enough.... And thats the end goal, if it aint broke, don't fix it. imo.

I am running an LC1. The gauge and the ground on the LC1 are both grounded to the same lug (metal by the radio). ECU has its own ground (stock ecu ground) I'm reading half a point difference. When the lc1 dash gauge reads 12 afr, ecu is reading 12.5 LC1 is connected to the ECU via a data cable.

with my mtx-l grounded to the power ground of the MS (boomslang harness to the stock grounding points) I have a .1 difference between the two.

Got any idea where the stock ecu is grounded and where to hook it up?

You should connect all but the LC1 heater ground, to the sensor ground pin on the ECU. LC1 heater ground can go to chassis or engine ground point.

"all but the lc1 heater ground" Basically you mean the gauge ground?

Gauge ground and analog output ground.

I must admit, after reading this thread I actually returned my lc1 for the MTx-l.

Pictures of the exact grounds would be great lol