Widebands That You Would or Wouldn't Buy

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HelmutVonAutobahn
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Re: Widebands That You Would or Wouldn't Buy

Post by HelmutVonAutobahn »

Yep. That sounds like a fractured sensor element.

It will probably keep eating sensors, unless you can find the source of the problem. I had theorized, when I looked at the LSU4.9 version of the MTX-L, that the heater control did not look like it kept up with the Bosch specification. You may have an application that is affected by that.

Installing one of the HBX-1 bung heatsinks may help. Just replacing sensors probably will not :(
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Re: Widebands That You Would or Wouldn't Buy

Post by HelmutVonAutobahn »

DelSolid:

From your website:
Image

How can you quote the PLX at 36ms with all that noise? Do the widebands get credit for noise amplitude, when calculating the responses ?

I know that the 30-0300, Zeitronics, and MTX-L/LC-2 are all pretty quiet, noise-wise. The others ? Especially PLX ?
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Re: Widebands That You Would or Wouldn't Buy

Post by fuzzysig »

MTX-L has a horrible analog output. it fluctuates a lot while gauge stays solid
people on pgmfi say its due to lack of sensor ground.

i don't know much about how wideband work so i cant say anything lol
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Re: Widebands That You Would or Wouldn't Buy

Post by Fred »

Digital gauges need lack to be useful to the eye. I would hope the output was vastly faster than the display. If the numbers are never steady, grounding is possible, if they're sometimes steady, perhaps it's just a crappy tune?
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HelmutVonAutobahn
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Re: Widebands That You Would or Wouldn't Buy

Post by HelmutVonAutobahn »

MTX-L has a horrible analog output. it fluctuates a lot while gauge stays solid
people on pgmfi say its due to lack of sensor ground.
Could be. I tested them on the bench. So, the ground wire was very short. Having the gauge share signal and power ground is not good practice.

Like Fred said, the displays are, usually, heavily, filtered.
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DelSolid
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Re: Widebands That You Would or Wouldn't Buy

Post by DelSolid »

HelmutVonAutobahn wrote:DelSolid:
How can you quote the PLX at 36ms with all that noise? Do the widebands get credit for noise amplitude, when calculating the responses ?

I know that the 30-0300, Zeitronics, and MTX-L/LC-2 are all pretty quiet, noise-wise. The others ? Especially PLX ?
You bring up a really important issue. The noise levels of the different controllers were all over the place. Some were really good and some were so bad as to be unusable (IMO), despite herculean efforts to give the best possible power, ground and capacitance setups to the devices under test.

Ultimately the filter applied was decided upon by the independent testing firm. I personally do not like their choice because they decided to use a median filter on all the units, which is possible to do in a post processing action on an existing data set, and it shifts the data the least, but is not something you can do in real time which is how the analog output data is used for feedback. Our units would have fared better (actually, others would have fared worse, take your pick on wording) if we ran without any analog output filtering at all and enforced a strict t63 threshold rule (time only stops when you cross the t63 threshold and stay across it). But some of the sensor outputs were so noisy that we literally could not have gotten a repeatable t63 time from them and people would be all angry. they would be accusing us of all sorts of shenanigans, So the filter was added along with the 8x test averages to give repeatable values and throw the one-time-wonders out.

But just remember, to keep things simple, this test is just measuring the response time of the sensors, not their accuracy, signal clarity or anything else. We wanted to keep the message simple.
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fuzzysig
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Re: Widebands That You Would or Wouldn't Buy

Post by fuzzysig »

is it possible to minimize the noise by using a diode?
and is it possible to minimize the fluctuation by using voltage stabilizer?
on a Honda when at low cruising rpm and during idle. the alternator falls back to 12.4 volts instead of 14.2

inside the MTX-L if anyone interested.

http://forum.pgmfi.org/viewtopic.php?f=2&t=23953
maybe theres a separate ground at the circuit board but not on the harness. there seens to be a lot of black wires lol

so which wideband has a serial or USB for direct logging? this crap is very confusing lol i assumed that it was a common feature by now but apparently not.
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Re: Widebands That You Would or Wouldn't Buy

Post by HelmutVonAutobahn »

DelSolid:

Do you have accuracy and and noise values for the various controllers?

Fuzzysig:

It may be possible to hack into the MTX-L and provide it a proper power ground, near the source pin of the heater MOSFET. That would require some work. I'll take a peak at mine.
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Re: Widebands That You Would or Wouldn't Buy

Post by fuzzysig »

mine is still taken apart I can take more pics if anyone needs.
what is the separate sensor ground for?
will it improve temp control or is it mostly for more stable analog output?
HelmutVonAutobahn
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Re: Widebands That You Would or Wouldn't Buy

Post by HelmutVonAutobahn »

After a quick perusal, it looks like a "signal ground" could be picked up off of, what appears to be, the programming header ( marked JP3 ). FFrom PIN1 ( square ). If you have a differential input, using that signal as the negative side will likely provide a cleaner signal. i.e. the heater noise SHOULD cancel out, via common mode.

The black harness wire looks to go through a shunt resistor; then, straight to the MOSFET. I would cut this wire as close as possible to the gauge. Then use HEAVY ( 14g or better ) wire to ground it to something solid, like the battery terminal. Make the run is as short as possible.

That's about the best you can do.
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