Does anybody know where i can buy cheap cylinder pressure sensor like
this one http://www.tfxengine.com/SensorsOverall.html (1250$)?
They are like widebands on the olden days.
They are expensive cause they are not common stuff yet.
When cars start coming with sensors like that in the plugs as standard then they´ll be well cheap
hi.I found the cheapest one for approx. 400$ that would fit into a hole drilled in a spark plug(threaded approx3-4mm).That was few months ago and unfortunately I can't remember where ???
Try to google it.
Keywords are:
-miniature
-subminiature
-ultra miniature
-micro
-pressure
-sensor
-transducer
Good luck :)
Sensor itself is just half of problem. Other is some data analysis equipment. Simple o-scope here is not enough.
Quote from: GintsK on November 24, 2009, 12:38:09 PM
Sensor itself is just half of problem. Other is some data analysis equipment. Simple o-scope here is not enough.
I have same equipment from my experiments with ion sensor. I need only sensor.
I agree Gints,but it depends what do You really want to see.If You wanna see exact point when the peak pressure occurs (deg ATDC), then You need something to calculate that angle from TDC (camsync) sensor and RPMs,and if You need simple knock indicator,than You actually need to know pressure level.I mean when knock occurs ,then in cyl. pressure is much higher then without knock.
Quote from: ryniobl on November 24, 2009, 03:16:27 PM
I agree Gints,but it depends what do You really want to see.If You wanna see exact point when the peak pressure occurs (deg ATDC), then You need something to calculate that angle from TDC (camsync) sensor and RPMs,and if You need simple knock indicator,than You actually need to know pressure level.I mean when knock occurs ,then in cyl. pressure is much higher then without knock.
for knock you only need high pass filter(>4-5kHz).
btw i have 60-2 trigger whell, so i can only with osciloscope can see where is PPP.
The signal processing requirements are not huge. I think you could probably do OK with some buffering electronics and a laptop sound card to monitor the trigger signal + USB scope for the pressure signal.
I can't see anything with a huge bandwidth here.
Any new spark plug which can measure cylinder pressure? Any cheap?
Quote from: MWfire on April 28, 2010, 07:14:02 PM
Any new spark plug which can measure cylinder pressure? Any cheap?
Be patient.I going to order it in monday ;)
and I will post some pictures of sparkplugs I have made.
Stay tuned
Quote from: ryniobl on May 01, 2010, 05:39:49 AM
Quote from: MWfire on April 28, 2010, 07:14:02 PM
Any new spark plug which can measure cylinder pressure? Any cheap?
Be patient.I going to order it in monday ;)
and I will post some pictures of sparkplugs I have made.
Stay tuned
Where did you order and what is price?
oh man.. this is exciting, can't wait for more details ;D
I have it ordered....finally :)
The one is here http://www.optrand.com/ click on ''product flier'' just above small picture.
The price is 980$ shipped.
It has 100Bar range and 0.1bar resolution.good enough. ;D I hope.
Lead time: 3-4 Weeks :-[
Quote from: ryniobl on May 13, 2010, 03:54:50 AM
I have it ordered....finally :)
The one is here http://www.optrand.com/ click on ''product flier'' just above small picture.
The price is 980$ shipped.
It has 100Bar range and 0.1bar resolution.good enough. ;D I hope.
Lead time: 3-4 Weeks :-[
I had problem with then, they just ignored me. Can you ask them for two more sensors?
And it's option to cheap change spark plug when is dead?
I asked if they can send 10 sensors ,and they said ok with 10%off and 140$ for shipping :)
Spark plug cost about 300$,but I have made one myself for free :) well almost.I destroyed many before I have done one.Now its easy.I will come up with some pictures soon.
Quote from: MWfire on May 13, 2010, 04:14:23 AM
I had problem with then, they just ignored me.
Maybe your Email was lost in spam box.Sometimes when i sending Emails to US I have to use US proxy,then I getting response.
Quote from: ryniobl on May 13, 2010, 04:27:19 AM
I asked if they can send 10 sensors ,and they said ok with 10%off and 140$ for shipping :)
Spark plug cost about 300$,but I have made one myself for free :) well almost.I destroyed many before I have done one.Now its easy.I will come up with some pictures soon.
Can you send me direct email of your conntact?
I allready made some software and hardware that implemate in vems for logging and maybee closed loop spark control. But I need two spark plugs to test that.
PM sent :)
What are expected cylinder pressures on high boost gasoline engines?
Have you asked for the price of 250 bar sensor?
Quote from: tonci on May 13, 2010, 01:48:09 PM
What are expected cylinder pressures on high boost gasoline engines?
Have you asked for the price of 250 bar sensor?
Here you have something
http://www.harleyc.com/prelude/articles/AllAboutMeanEffectivePressure/default.html
http://www.epi-eng.com/piston_engine_technology/bmep_performance_yardstick.htm
http://www.bmepfuelandtuning.com/html/what_is_bmep_.html
I spoke to them first about 200Bar sensor and they didn't say that is different price.The only difference was AutoPSI-TC(TemperatureCompensated) is about 100$ more expensive than AutoPSI-S .They said also 200Bar one has to little accuracy for partial/low throttle tuning of street engines.
Keep in mind all units are imperial ;)
any updates on this?
Quote from: ryniobl on May 13, 2010, 04:27:19 AM
I asked if they can send 10 sensors ,and they said ok with 10%off and 140$ for shipping :)
Spark plug cost about 300$,but I have made one myself for free :) well almost.I destroyed many before I have done one.Now its easy.I will come up with some pictures soon.
Do you have any pictures of your modded spark plug.
Quote from: tonci on June 02, 2010, 10:12:46 PM
Do you have any pictures of your modded spark plug.
Finally i got that sensor ;D
Look at the pictures here http://picasaweb.google.com/ryniobl77/CylinderPressure#
Read comments under each picture :)
i love the progress!
what are you using to collect the data at this point? do you need to sample data at a certain time?
Quote from: multiplex on June 20, 2010, 06:01:09 PM
i love the progress!
what are you using to collect the data at this point? do you need to sample data at a certain time?
Oscilloscope with timebase set at 5-10us works fine ;D
So basically you are drilling a port right through the steel body of the plug so it can access the chamber ?
The fitting the sensor into the plug body ?
Wont that damage the plug at all ? Or does it still perform ok ?
Interesting stuff.
Quote from: stevieturbo on June 20, 2010, 08:00:23 PM
So basically you are drilling a port right through the steel body of the plug so it can access the chamber ?
Yes
Quote from: stevieturbo on June 20, 2010, 08:00:23 PM
The fitting the sensor into the plug body ?
Yes
Quote from: stevieturbo on June 20, 2010, 08:00:23 PM
Wont that damage the plug at all ? Or does it still perform ok ?
No.It works fine.
Quote from: stevieturbo on June 20, 2010, 08:00:23 PM
Interesting stuff.
;D
are you triggering off of something? how do you start the logging, reference tdc? spark?
This thread is useless without pictures and data ;D
nice!
Quote from: [email protected] on June 21, 2010, 05:43:58 AM
This thread is useless without pictures and data ;D
linky 7 posts up from this one ;)
Literally the most interesting EFI stuff on the internet right now.!!
More info as you progress :)
Quote from: multiplex on June 20, 2010, 10:52:57 PM
are you triggering off of something? how do you start the logging, reference tdc? spark?
That what you seen on the pictures it was sensor signal caught on oscilloscope,triggered on rising edge.
Now I made a bracket for another VR sensor which shows 6 deg ATDC as a 1st tooth after missing(60-2) on cyl 3 and 4.I wish to have it on cyl no 5 and 2(no5 is prone to knock in BMWs),but it would be a little difficult.
Im very busy last days ,and i need to do some more testing :) I will show up soon with some new pictures.
Ohhhh man i sleep so little ;D
MWfire,Tonci have you ordered sensors yet?
Yes, order is made.
BTW you can use knock integral signal for trigger and set it to tdc.
7th pin of knock chip
http://www.vems.hu/files/genboardv3/v3.3/v33_sch.pdf
http://focus.ti.com/lit/ds/symlink/tpic8101.pdf
Quote from: MWfire on June 21, 2010, 07:40:51 PM
Yes, order is made.
BTW you can use knock integral signal for trigger and set it to tdc.
7th pin of knock chip
http://www.vems.hu/files/genboardv3/v3.3/v33_sch.pdf
http://focus.ti.com/lit/ds/symlink/tpic8101.pdf
Thanks :) but in this case i use diffrent engine management system.
Really you need to plot pressure over crank angle.
i need to order one of the sensors! we should get a group buy going ;D
Quote from: [email protected] on June 22, 2010, 05:26:00 AM
Really you need to plot pressure over crank angle.
That's what i going to do.Now i remove additional sensor and connect another ECU parallel,and set it the way to generate rising edge at 5 deg ATDC on the IGN output.I think it will work ;D
one more idea was just born in my head :) Can anyone confirm,how much time engine needs to turn the crankshaft by 10 degrees?
I think at 1000rpm needs 1.667ms and at 7000rpm needs 0.238ms.Is this correct?
Quote from: ryniobl on June 22, 2010, 03:31:39 PM
Quote from: [email protected] on June 22, 2010, 05:26:00 AM
Really you need to plot pressure over crank angle.
That's what i going to do.Now i remove additional sensor and connect another ECU parallel,and set it the way to generate rising edge at 5 deg ATDC on the IGN output.I think it will work ;D
one more idea was just born in my head :) Can anyone confirm,how much time engine needs to turn the crankshaft by 10 degrees?
I think at 1000rpm needs 1.667ms and at 7000rpm needs 0.238ms.Is this correct?
maybee it's better to put 16-18deg ATDC, that is point what you aiming for peak pressure.
10deg= 1/(rpm*6/deg)
so for 1000rpm it is 1.667ms as you write.
Quote from: MWfire on June 21, 2010, 07:40:51 PM
BTW you can use knock integral signal for trigger and set it to tdc.
7th pin of knock chip
That is an excellent idea, filed away for future use :)
Well...I made it ! :D
I have it tested on the bench.
I going to connect ecu parallel,but using it to generate injection pulse which duration is exactly 10deg at certain rpm.I set rising edge to be at 5deg ATDC,and this way we will see the window which starts with rising edge and ends falling edge.PPP hve to be inside window :D How simple is that!
I have it tested on the bench up to 10000rpms.It seems to be just FINE!and very accurate!
Pictures will come tomorrow.
Now I have to find the way to set it on TDC.I was thinking about ultra bright LED diode connected to inj output...
Quote from: ryniobl on June 22, 2010, 08:37:50 PM
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
Quote from: MWfire on June 23, 2010, 07:04:15 AM
Quote from: ryniobl on June 22, 2010, 08:37:50 PM
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
I´m excited !!
Quote from: gunni on June 23, 2010, 07:35:00 PM
I´m excited !!
Me too.Dyno session in friday :)
Quote from: ryniobl on June 23, 2010, 07:08:42 PM
Quote from: MWfire on June 23, 2010, 07:04:15 AM
Quote from: ryniobl on June 22, 2010, 08:37:50 PM
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 :)
Just added some more pictures.Look at it :)
amazing ;)
waiting for dyno updates :P
and maybe a little more background on exactly how to tune with this sensor.
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...
Quote from: ryniobl on July 07, 2010, 04:32:46 PM
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?
Quote from: MWfire on July 08, 2010, 06:52:41 AM
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.
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.
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.
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.
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
(http://imgur.com/KaLpM.jpg)
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.
This looks like it might be useful if anyone has access:
http://papers.sae.org/930882/
Quote from: BigD on July 08, 2010, 09:27:41 AM
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.
Quote from: BigD on July 08, 2010, 09:27:41 AM
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 :-\
(http://img411.imageshack.us/img411/7552/optrand3.jpg)
Aaah, gotcha, thanks!
has anyone had any luck finding the Toyota part? is it only used in Russia. I even called Toyota but they need a VIN # to get parts.
I have looked at the part places but can find anything.
and all the searches of the 89468-20020 turned up not english.
The Russian pages say it's from the 7A-FE (4A got them too). So try 93-97 Corolla or 93-99 Celica.
I'm still searching but found this:
http://carprogrammer.com/Z28/PCM/SAE/2000-01-0932.pdf
Neat highlites:
The SPB pressure sensor operates in a structural load path that is
very linear and well behaved. Cylinder pressure acting on
the combustion chamber creates a force that is elastically
transferred through the cylinder head structure to the
head bolts. A portion of this total force is transferred in
compression through the spark plug boss and has a
magnitude of about 2200 N at maximum cylinder
pressure (6.8 MPa). This provides a reasonable but not
excessive force for sensing. To detect the force, a
shoulder is machined on the inner diameter of the spark
plug boss and the sensor is preloaded onto the shoulder
using fastening threads. To accommodate the sensor, the
cast outer diameter of the upper spark plug boss is
increased about 6 mm. Because the sensor is located
high within the spark plug boss, the sensor has no
detrimental effect on spark plug cooling. The sensor is
responsive to compressive forces applied through the
sensor bottom face (see Figure 3).
A detailed thermal-structural analysis for the sensor and
cylinder head was performed to confirm load path
sensitivity to cylinder pressure and insensitivity to
extraneous loads (Figure 4). Various extraneous loads
are known (valve train dynamics, thermal loads, etc),
however, since loads caused by cylinder pressure are
large, tests show that error signals could be effectively
isolated and minimized (see section on signal validation).
Frequency response of the installed sensor is about 20
kHz, which is adequate for detection of cylinder pressure
including combustion knock.
The advantages of this overall sensing concept are:
1. Direct access to the combustion chamber is not
required
2. Due to abundance of cooling water surrounding the
spark plug boss, sensor operating temperatures and
hot soak temperatures are relatively low (140 C
maximum).
3. Due to mounting outside of the combustion chamber,
the sensor is insensitive to several common types of
thermal errors including intracycle flame arrival
effects and signal drift during engine load transients.
Suddenly that has re-sparked my interest in engine management systems.
Quote from: [email protected] on July 09, 2010, 04:56:56 AM
Suddenly that has re-sparked my interest in engine management systems.
Hope there was no knock!
Just looking at a spark plug. I have a NGK BKR6EKPB-11 it is much smaller on the top for cops. it seems the smaller size would make for a better time doing the mod.
and with the bump I think it would not be bigger then the normal large plug. this is needed if the plug needs to go down a tube like a lot of DOHC heads.
the 2nd thing I thought of is to use a very tiny drill and drill the outer threaded shell all the way up. The shell seems to be over 2mm thick so it would have to be a very tiny drill.
I think the rest would be the same weld a blob cross drill,re-weld. etc. but get rid of the trench.