Widebands That You Would or Wouldn't Buy

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

Post by Daemos »

HelmutVonAutobahn wrote:Update... the firmware process did work with the MTX-L. I tried again with the LC-2. But, got the same result. Now to try the LSU4.9.
Please keep us updated! What test conditions will you be running? Will you compare it to other widebands you have?
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Re: Widebands That You Would or Wouldn't Buy

Post by Daemos »

HelmutVonAutobahn wrote: Of course, just sitting on the bench, it will find an equilibrium point and stay there; even at slower control rates.

Since The MTX-L uses the same measurement cycle to measure the sensor temperature, they are only getting 18 to 40 temperature samples per second. Much less than the required rate. This could lead to wide swings in sensor temperature ( and possible damage or premature aging ) before the control loop has a chance to catch up to a hot or cold spike.

For example, decel fuel injector cutoff causes a cold spike and they only get 18 samples/second for heater control in free air.

Maybe it's OK. But, I don't think Bosh would have upped the control loop speed requirement 50X if there was not a reason ?
Thank you for the testing! Very interesting! (I made another post but as I'm too new, it needs to be moderated!) I have not yet installed the LSU 4.9 into my MTX-L yet, however, where would you recommend I place the sensor? I have two possible locations approx 4-6" away from the turbo or more downstream approx 2.5 feet away from the turbo? These are approximate only. I'd have to take apart the exhaust to get accurate measurements.
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Re: Widebands That You Would or Wouldn't Buy

Post by HelmutVonAutobahn »

Ummm.. That was pretty much all the testing that I was planing to do. There is a bunch of other stuff that can be tested. Like... Does it do the required low-voltage water evaporation pre-heat phase before warm-up? Checking the dynamic response of the heater/temp control. What happens if you have it programmed for one type of sensor ( or it gets reset ) but, you plug in the other type? And, of course, what is the actual response time of the AFR readings ? But, I will leave that to someone more motivated than me :)

I don't know why it worked on the MTX-L but, not on the LC-2. Maybe there will be another update coming for that.


As for sensor placement. Given the slow sampling rate of the sensor element temperature, I would recommend placing the sensor as far downwind from the turbo as possible. You want to keep the EGT swings to a minimum. I would also recommend using one of Innovate's HBX-1 sensor heat-sinks. I have seen them on eBay for about $40. http://www.ebay.com/itm/261868788904 Cheap insurance.
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Re: Widebands That You Would or Wouldn't Buy

Post by Daemos »

HelmutVonAutobahn wrote:Ummm.. That was pretty much all the testing that I was planing to do. There is a bunch of other stuff that can be tested. Like... Does it do the required low-voltage water evaporation pre-heat phase before warm-up? Checking the dynamic response of the heater/temp control. What happens if you have it programmed for one type of sensor ( or it gets reset ) but, you plug in the other type? And, of course, what is the actual response time of the AFR readings ? But, I will leave that to someone more motivated than me :)

I don't know why it worked on the MTX-L but, not on the LC-2. Maybe there will be another update coming for that.


As for sensor placement. Given the slow sampling rate of the sensor element temperature, I would recommend placing the sensor as far downwind from the turbo as possible. You want to keep the EGT swings to a minimum. I would also recommend using one of Innovate's HBX-1 sensor heat-sinks. I have seen them on eBay for about $40. http://www.ebay.com/itm/261868788904 Cheap insurance.
Sorry, as I stated before my post was being moderated (I posted it prior to you posting test results!

I have ordered one of the heat sinks off the ebay link you posted! hopefully that'll make it more reliable for long term use.
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Re: Widebands That You Would or Wouldn't Buy

Post by HelmutVonAutobahn »

Sorry, as I stated before my post was being moderated (I posted it prior to you posting test results
Gotcha :)

The heatsink should help to keep the EGTs at the sensor element from swinging as radically. Hopefully preventing thermal shock. That is what damages sensors.

Having the exhaust gas travel through the small passages of the big chunk of steel which has a very high thermal mass should slow the temperature swings down a bit, compared to leaving the sensor element hanging right out in the gas stream. i.e. the exhaust gas at the sensor tends to take on the temperature of the heatsink material before it hits the ceramic element.

If the heatsink is installed correctly ( with the side hole facing upstream ), there should be no measurable effect on response time. These are probably Innovate's best product :)
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Re: Widebands That You Would or Wouldn't Buy

Post by Hentai »

Seems like a poor product to have to deal with it in a manner that even the designed of the sensor ( bosch ) has said to put the sensor as close as possible with staying in the limits of the sensor.
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Re: Widebands That You Would or Wouldn't Buy

Post by HelmutVonAutobahn »

Seems like a poor product to have to deal with ...
That might be taking it a bit far.

It may be that it is OK to run the temperature control loop that slow. I am only going by the spec from Bosch. My thinking is that the longer the delay between measurements, the more extreme the swings on the heater power need to be to "catch up". At 100 measurements per second, the heater may swing between 7v and 9v. While at 18 measurements per second, it might need to swing 4v to 12v to try to keep up. This would put a lot more thermal stress on the ceramic element. I have not done any actual dynamic response testing on this. So, YMMV.

It may also be that this is just a stopgap, while, they update their hardware designs for the new sensor. Same goes for the PLX SM-AFR GEN4 and AEM 4110. Seems that everyone switched over to the LSU4.9 sensor as the LSU4.2s started to become scarce, by tweaking their existing hardware/firmware.

AEM probably has the easier "upgrade path", as they use the Bosch CJ1xx chips. So, HW-wise, they can just drop in whatever component values that the Bosch reference design calls out for the LSU4.9

Innovate and PLX build their controllers from scratch. So, they would probably need a more involved development cycle.


... or not.
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Re: Widebands That You Would or Wouldn't Buy

Post by HelmutVonAutobahn »

Or, maybe, I was right :) Update from SEMA

AEM showed a new "X-series" wideband ( sounds like a cheesey 1950s SciFi name ). Based on some new "patent-pending design" that is, either in addition to, or, instead of the Bosch CJ1xx chip. They now claim the fastest response times, according to "independent testing". I do know that it has CANBus output. It is also very thin. About the same thickness as the PLX DM6 gauge. But, the wideband controller is built-in, rather than an external module.

Can't wait to crack one open :)
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Re: Widebands That You Would or Wouldn't Buy

Post by HelmutVonAutobahn »

Got one ( AEM 30-0300 "X-Series" )

So far, so good.

The display and controller are on the same PCB. ( why it is so thin )
There is no Bosch CJ1xx chip
The CPU is an Atmel ATMEGA16M1 ( hard to read )
The big octagonal inductor is for the heater. It is DC-DC driven
The small inductor is for a switching regulator ( probably for the display LEDs )
There is a separate linear regulator ( probably for analog stuff )
There is a sprinkling of TVS diodes and PTC fuses.
The DAC output is pretty clean with the sensor in straight CO2.
The CAN output sends at a 100 packets per second rate. Not decoded yet.
There is some flux on one chip. ( Probably reworked )
Not a fan of the way it screws together.

I will do a little poking around.
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Fred
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Re: Widebands That You Would or Wouldn't Buy

Post by Fred »

Interesting, looking forward to more. Thanks for the continued updates, I really appreciate your contributions to this thread! :-)

In other news, I put my money where my mouth is a day or two ago and ordered one of Alan's 14point7.com SLC Pure Plus 2.1 and LSU4.9 combos to use as a GP tool with a tail pipe sniffer tube (that I've not designed or built yet). Will be handy for measuring various cars that have not got an easy way to wideband for whatever reason (NA install, rusted bung/sensor, no MIG and no hole, etc). A friend ordered the same unit combo at the same time, so he'll be testing that out too. Probably won't be able to pick a difference from the SLC_OEM unit I already have which has been awesome for me on the hotel, but thought I'd give it a mention anyway.

Thread on DIY sniffer design: viewtopic.php?f=15&t=2638

Fred.
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