Knock sensor useage on ACVW's

[Piledriver]

Ion sensing is ~dead, historical roadkill via modern technology.

Ion sensing was always heavy voodoo, and has been far surpassed in modern vehicles by direct cylinder pressure measurement sensors. There are ~millions of these beasties out there, in engines, today.
I need 4 if you score some cheap...

Ion sense only ever really worked at higher loads, and was most commonly used as a knock sensor or advanced combustion miss detector.(usually both) rather than for PPP, which was nontrivial as the signal/noise ratio was brutal.

Google Sensata CPO...

Many modern diesels also have glow plugs that also double as direct pressure sensors, same tech.
(2011+ VW TDi and its Bluetec brethren from other OEMs have one, each.)
And its ~immune to engine mechanical noise.

This makes it perfect for PPP and knock measurement, as the heavy lifting of pulling the signal from the noise is not needed.
It's clean, direct pressure data. Period. They even work at idle.

These moderm MEMS-based sensors put out a nice clean 0-5v, and yes, the output (with some very minor massaging) could be fed to the knock subsystem... and an analog input.

[Passatman]

Earlier this year the guys at Diyautotune put out a poll on facebook asking what we would like to see next in megasquirt. I asked for them to see if they could incorporate cylinder pressure read outs from the ECU. I really hope someone listened and they are trying to make this happen.

[mads b (dk)]

What is the price on of this cpos or glowplugs with sensor in

Samsung S5

[Piledriver]

What is the price on of this cpos or glowplugs with sensor in

Samsung S5

Have not been able to find a part# for the CPOS.
Sensata, like Delphi, won't say, sends back a form letter saying they only deal with oems.
Mercedes is supposedly using them as the ceramic glow plugs are far more reliable, the CPO was meant to be used with separate glow plugs or Gas engine.

The Beru glow plugs can be had for ~$130, every 2013+ TDi has one. Nail the connector too.
You will be making some sort of long tubular adapter as they are very long, and cannot take ACVW CHT temps.

Might live in the airstream though, I have actually been considering water cooling some T4 heads to keep the pressure sensors and a set of GDI injectors alive bolted to the chambers.

I don't think even MS3 has enough CPU or fast enough sampling to do PPP directly, or even log it fast enough to be useful.

The audio system of your laptop is fast enough though, 44KHz@16 bits/sample, all you need is relative waveform and a sync pulse or sample window on the other channel to calculate timing.

You would probably want an FPGA or DSP setup, something designed for purpose.
That isn't hyper expensive to do these days..

I kept an old AMD motherboard with a sadly no longer developed NVidia audio chip, it can sample or output 2 channels, 16 bit @480KHz.(not a typo) it had 10X oversampling and had a lot of other borderline "pro audio" features, but cost far too much for cheap motherboards and wasn't pro enough for the high end stuff, so it was dropped, as nobody cared.

My DAQcard setup sorta works, it could potentially sample 2 channels at 25 KHz/10 bit ea, with a digital trigger or sample window.
The Linux drivers are sadly pretty primitive but it does work. I should really beat up on that, picked up a PCMCIA<>MiniPCIE adapter that works well with it, so I can use it with my X200 tuning laptop.(Core2duo/8GB)

Need to add the Comedi_command interface hooks to the driver, then it can be used with xoscope or even SciLab.