Chas

Just got in the M300 unit from PLXDevices. Looks pretty sharp. Now...I know a few people here have at least ordered this little number from them, and for those of you I have a question or two.

First, how did you run the narrowband grey wire to the DME...did you cut the stock wire from the wiring harness and attach the grey nb output from the m300 control unit? I can't even imagine the pain of unbundling the wires to pick out the wire that goes to the stock o2. Some details here would be VERY helpful.

Secondly, has anyone tested to see if the noise filter capacitor is necessary?

I got the optional converter which translates the 0-5v wb signal to a directly proportional "readable" 0-1v wb signal for an autometer a/f gauge. I imagine I don't need a filter cap between the control unit and converter...?

Thanks in advance for any information...also any advice or tricks from folks who have done the install and can pass on some install tricks that might not be obvious or in the instructions


I will be sure to post a follow-up and let anyone who cares to know how the unit works...I am definitely looking forward to having wide band monitoring on board

adrial

So even without the converter it comes with a narrowband output that you can hook up to the DME?

Konstantin

dioes it has dataloging?
what other futures?
temp and pressure compensation?
how it compares to teh tech edge one?


Konstantin

Chas

no datalogging, though the output can easily attach to a map/maf piggyback system that does. I don't have any experience with the tech edge unit, so no comment there. What it is...is something so simple it's brilliant...kind of like the little rubber spikey mat thing you put the bar soap on in your shower to keep it from getting all gooey on the bottom, making it last longer...know what I'm talking about?

so basically it's a box...a little bigger than a pack of cigarrettes (no not the soap holder...I'm back to the wbo2)...it connects to a Bosch LSU 4 or 4.2 wb sensor. It has two outputs...one is your 0-5v linear wide band output...the other is a simulated 14.7 toggle low/high narrow band output, just like your dme is used to seeing. So the beauty of it is you get wideband readings...and a simulated narrowband that actually toggles where it should. You also only need one o2 sensor.

adrial, you are correct....all the converter does is scale down the linear 0-5v output to a (still linear) 0-1v output for your autometer (or whatever) a/f gauge. Now recall that the autometer gauge operates on a 0.025 - 1.000v scale, and each LED on the gauge corresponds to a 0.05v increment. Also remember that in wide-band-world, a/f = (2 * Voltage) + 10. So scale that down by a factor of 5, and you quickly realize that each light on the autometer gauge corresponds to to a 10:1 - 20:1 a/f, in increments of 0.5.

I find this to be all sorts of nifty...with a boost gauge and an a/f gauge outputting accurate 10:1 - 20:1 readings mounted in a gauge pod...this gives some nice heads up that things are goin alright.

...I just can't wait to get a piggyback system and MODIFY and DATALOG this stuff :-)

Hot damn...sorry that was so many words....my questions from my initial post still stands.

Oh, and go to www.plxdevices.com to check it out. No affiliation...just excited customer

Jfrahm

http://www.plxdevices.com/

cpt_koolbeenz

How long did it take to get it? I ordered mine last friday - hopefully it will be here soon!!

Yes you have to tap into the harness. Look Here

The filter cap would be a good idea IMO.

Chas

I'm in VA, and it took a matter of a few days...

I guess pulling the pin 24 is the easiest solution...

Chas

Another question....SpeedWag and I were discussing the possibility of the VW LSU4 sensor that the M300 uses overheating in the stock location. Has anyone had some experience with using this sensor in the crossover pipe vs. downstream of the turbo???

cpt_koolbeenz

Seems like the exhaust would be pretty cool in that position. Why do you think it would overheat?

Chas

I bet you might have mis-read....the stock location is between the headers and the turbo...you get some very high temperatures (read: ever seen your headers glow red before?), along with some really high pressure (ahhh those good ole efficient 26/6's)

High heat + added pressure = friggin' hot!

Or maybe I got something wrong...?

cpt_koolbeenz

Oh yeah - forgot which side of the turbo it was on (had to run and check)... I missed that post.

Is there more of a heat problem with the LS4U that there isn't with the stock one?

eastendr

I bought the PLX 250 (non digital display version) a week ago after discussions with PLX.

I wanted to replace the stock narrowband sensor with a wideband and use the narrow band output from the M250 to feed the DME & HKS CAMP datalloger.

I also wanted to use the wideband output to feed the Link AFM gauge that I bought from Danno in it's wideband mode.

The installation was very easy, both sensor and wiring.

The problem I have is that the LINK gauge reads backwards i.e. 10:1 on overrun and 17:1 on boost !

It seems that there is a fundemental difference between the voltages sent by the M250 and needed by the Link Gauge. The voltage needs to be inverted.

I have spoken to support at PLX about this (they have been VERY helpful throughout) and am awaiting a reply. I think the PLX module will need modifying to invert the wideband output for use with the LINK gauge.

I'll post again when we've found an answer.

Rick.

Magown

eastendr, where did you mount the sensor?

eastendr

Direct replacement for the standard O2 sensor - in the downpipe

Chas

Downpipe? you mean crossover pipe? Are we talkin '86 951 here?