cylinder pressure sensor

[ryniobl]

I´m excited !!

Me too.Dyno session in friday :)

[MWfire]

Now I have to find the way to set it on TDC.I was thinking about ultra bright LED diode connected to inj output...

or use stroboscope

LED works fine.I set pulse width to 64us,and TDC looks like frozen :)

Here is plot.
blue- 10deg window
red-cyl press(it's on idle ,so you can barely see ppp)

http://picasaweb.google.com/ryniobl77/CylinderPressure#5486072317301739026

for some reason images won't work,so i pasted link

nice. I can't wait WOT plot :)

[ryniobl]

Just added some more pictures.Look at it :)

[z0tya]

amazing ;)

[multiplex]

waiting for dyno updates  :P

and maybe a little more background on exactly how to tune with this sensor.

[ryniobl]

well....sensor is broken down  :-[ I overheat interface.I kept it under hood,and it just stopped to give a signal.Stupid me  :-\ ,it says clear in manual ,temp. range -20degC to 60degC,and it was over 60degC for sure....now I sent it back to repair.hope I don't have to buy new one.....or even if i have to ,I will do!
The good thing is it was working perfectly before it failed!!! i mean that idea with pulse width  ;D and something very interesting-the car was misfiring over 1Bar of boost,and just at 1Bar it was showing pressure with double peak! Great tool! Unfortunately I have no picture of it...

[MWfire]

well....sensor is broken down  :-[ I overheat interface.I kept it under hood,and it just stopped to give a signal.Stupid me  :-\ ,it says clear in manual ,temp. range -20degC to 60degC,and it was over 60degC for sure....now I sent it back to repair.hope I don't have to buy new one.....or even if i have to ,I will do!
The good thing is it was working perfectly before it failed!!! i mean that idea with pulse width  ;D and something very interesting-the car was misfiring over 1Bar of boost,and just at 1Bar it was showing pressure with double peak! Great tool! Unfortunately I have no picture of it...

good to know, so sensor is good but interface is dead?

two peaks, maybee knock ? Do you have pictures?

[ryniobl]

good to know, so sensor is good but interface is dead?

two peaks, maybee knock ? Do you have pictures?

I think interface is dead,when i took it in my hand right after it stopped working ,it was hot.

[[email protected]]

I wonder if there are methods of isolating the gasses between the cylinder and the sensor, as this would help reduce the temperature.  I remember talking to Emil about the way they were using sensors to measure exhaust manifold back pressure, and they found that a couple of meters of copper brake pipe between the manifold take off and the sensor cooled the gasses enough to prolong the life of the sensor.

[BigD]

Changing the temperature would change the pressure though. I guess if you only measure the delta then it might not matter.

I'm a bit confused though - how can a sensor designed to meter combustion gasses have a temp ceiling of 60C? That won't even get you a cup of coffee.

[[email protected]]

As I understand it the sensor is just a high pressure sensor - not one hardened for extreme temperatures.

Pressure pattern/delta is more important than actual figures, it will allow the tuner to try and get peak pressure at ~17deg ATDC, and ensure that they're not getting detonation while it's happening.

[BigD]

For what it's worth, seems like Toyota's had combustion pressure sensors in their engines since 1992.

Like this from the 7A Corollas, pn 89468-20020



I haven't been able to find any others, and the pages about this one are mostly in Russian - which is convenient but weird. I also can't find a good pic to show where these go, but seems like in the head somewhere.

[dnb]

This looks like it might be useful if anyone has access:

http://papers.sae.org/930882/

[lugnuts]

I'm a bit confused though - how can a sensor designed to meter combustion gasses have a temp ceiling of 60C? That won't even get you a cup of coffee.

He's saying that the unit/interface is broken from the heat, not the actual pressure sensor in the spark plug.

[ryniobl]

I'm a bit confused though - how can a sensor designed to meter combustion gasses have a temp ceiling of 60C? That won't even get you a cup of coffee.

Sensor is rated for 380degC ,sensor cable for 200degC ,but electronic interface for 60degC,and that is the problem.It has 2m fiber optic cable,so it's long enough to keep interface in a cool place,but I was lazy and that's why it happened  :-\