Flow vs Pressure

[rotrex]

Hello Parmas,
I already did so I believe.

Fueling is controlled by the ECU running closed loop at all times employing a AFR target table.. Shall the methanol supply be reduced or seize, the ECU can add up to 30% of fuel to maintain that target AFR. I could adjust the regulation range even further.

The knock controller is a J&S Safeguard vampire unit. It works by being able to retard ignition by up to 20 deg (currently set to 10 max) within one single revolution for individual cylinders depending on knock intensity. It then reapplies fully advance by bringing back 1 (for 10 deg max range) or 2 deg (for 20 deg max retard range) every couple of revolutions.
It uses a standard BOSCH knock sensor. I have mounted their gauge, too so I can see what is happening.
It sometimes misses light knock, but the mid and heavy stuff is reliably regulated.
If you get a heavy misfire, e.g. Due to water meth failing or fuel air lock, it retards by 10 deg within a single revolution. This drops all power, but with it also all force. Light knock at part throttle you can barely feel. It typically pulls 2-4 deg.
I have tried the bigger range of 20 deg retatrd, but this essentially feels like someone pulled the plug out of your ignition coil. I believe this is more useful for NA two valve engines with old and slow combustion chamber designs that need up to 40 deg of advance at WOT to make power.
http://www.jandssafeguard.com

Then last but not least, I have mounted a pressure sensor in my water / methanol fuel rail. If the pressure drops in there, e.g. Due to pump failure or running out of fluid, it triggers a map switch. This is a ECU feature of my Emerald K3 ECU. It switches to a map I have set-up to run richer and with less ignition advance at WOT, so it runs without water / meth, albeit with less power. I do not have any boost control. If you have boost control, most turbo cars have, you can also just reduce boost and run with petrol alone.

[parmas]

Originally Posted by rotrex

Hello Parmas,
I already did so I believe.

Fueling is controlled by the ECU running closed loop at all times employing a AFR target table.. Shall the methanol supply be reduced or seize, the ECU can add up to 30% of fuel to maintain that target AFR. I could adjust the regulation range even further.

The above safety feature shall only work if you inject a small amount of methanol circa 15%. If you normally see 11Afr with meth and suddenly dropped to 13Afr, the ecu could adjust fuelling back to 11Afr but still ignition timing is according water/meth. Knock should still happen although it's more safe than nothing

The knock controller is a J&S Safeguard vampire unit. It works by being able to retard ignition by up to 20 deg (currently set to 10 max) within one single revolution for individual cylinders depending on knock intensity. It then reapplies fully advance by bringing back 1 (for 10 deg max range) or 2 deg (for 20 deg max retard range) every couple of revolutions.
It uses a standard BOSCH knock sensor. I have mounted their gauge, too so I can see what is happening.
It sometimes misses light knock, but the mid and heavy stuff is reliably regulated.
If you get a heavy misfire, e.g. Due to water meth failing or fuel air lock, it retards by 10 deg within a single revolution. This drops all power, but with it also all force. Light knock at part throttle you can barely feel. It typically pulls 2-4 deg.
I have tried the bigger range of 20 deg retatrd, but this essentially feels like someone pulled the plug out of your ignition coil. I believe this is more useful for NA two valve engines with old and slow combustion chamber designs that need up to 40 deg of advance at WOT to make power.
http://www.jandssafeguard.com

Thanks for the link. The system looks promising especially because of using stock knock sensor, features, fine-tuning and realtime-gauge.

The problem is I don't like external controllers apart ecu to manage the ignition system. I like better to let the ecu be the manager like changing map or reduce timing accordingly. Also the system mentions that retard timing by increasing dwell on coils which is not a good idea (depending how much dwell it actually increases). Coils could overheat that way.

Also how do the system understand that knocking happens on cylinder 1 and not cylinder 4 if only one middle knock sensor is used ?



Then last but not least, I have mounted a pressure sensor in my water / methanol fuel rail. If the pressure drops in there, e.g. Due to pump failure or running out of fluid, it triggers a map switch. This is a ECU feature of my Emerald K3 ECU. It switches to a map I have set-up to run richer and with less ignition advance at WOT, so it runs without water / meth, albeit with less power. I do not have any boost control. If you have boost control, most turbo cars have, you can also just reduce boost and run with petrol alone.

Good feature. What pressure sensor did you used and how did you set it from the software ?

....................................

[rotrex]

If your ECU offers knock control, even better.
The coil does not overheat as your engine is not permanently knocking to the maximum degree, say for minutes at the time. It also extends the dwell by max 10 deg in my config. So that is a few ms the most and that every few seconds. Nothing happens. At 6000 rpm for a I4 engine this corresponds to a extra 0.27ms dwell or say you have a total dwell of 3ms about 10% extra dwell every here and there. Nothing to worry about.
Most of the time the J&s does not do anything, even in Spa being at WOT some 50% of every lap. As you now get a good feel where the knock spots are, you eliminate them from your map. This way it only takes care about the exceptional knock instances.

Regarding cylinders. The units are configured for a specific engine configuration, say a inline 4 and distributor ignition with a single coil. If knock occurs, it knows that the very same cylinder is ignited 4 sparks later. It does not know if it is 1,2,3 or 4 as there is no cam phase sensor. But it knows when the same one is about to fire again. :-) And that is all that counts. You get versions for whatever engine config you have. V8 flat crank, Cross crank, I6, distributor, distributorless, 8x coil on plug, batch ignition, sequential ignition. Just tell him what you need. It is a one man company. The owner knows the designer and the programmer pretty well :-) His wife does the admin.

A single knock sensor captures knock all round the block. Aluminium is a good sound conductor. Most engines get around with a single sensor per four cylinder bank. I6 engines often have two, V12 sometimes 4.
I have observed it applying 4 different levels of retard on 4 different cylinders as indicated by 4 LEDs illuminated. If 1 to 4 cylinders have the same retard you only see 1 LED. You can also set the J&S to apply global retard on all cylinders.

The pressure switch is a Hobbs switch that was left over in my Aquamist 2c kit and the SW is a standard feature of my Emerald K3 ECU. It works from a analog input. It tells the ECU to switch maps past adjustable voltage threshold. The rest is a resistor across the switch and a internal pull up resistor :-)

[parmas]

Originally Posted by rotrex

If your ECU offers knock control, even better.
The coil does not overheat as your engine is not permanently knocking to the maximum degree, say for minutes at the time. It also extends the dwell by max 10 deg in my config. So that is a few ms the most and that every few seconds. Nothing happens. At 6000 rpm for a I4 engine this corresponds to a extra 0.27ms dwell or say you have a total dwell of 3ms about 10% extra dwell every here and there. Nothing to worry about.
Most of the time the J&s does not do anything, even in Spa being at WOT some 50% of every lap. As you now get a good feel where the knock spots are, you eliminate them from your map. This way it only takes care about the exceptional knock instances.

Regarding cylinders. The units are configured for a specific engine configuration, say a inline 4 and distributor ignition with a single coil. If knock occurs, it knows that the very same cylinder is ignited 4 sparks later. It does not know if it is 1,2,3 or 4 as there is no cam phase sensor. But it knows when the same one is about to fire again. :-) And that is all that counts. You get versions for whatever engine config you have. V8 flat crank, Cross crank, I6, distributor, distributorless, 8x coil on plug, batch ignition, sequential ignition. Just tell him what you need. It is a one man company. The owner knows the designer and the programmer pretty well :-) His wife does the admin.

A single knock sensor captures knock all round the block. Aluminium is a good sound conductor. Most engines get around with a single sensor per four cylinder bank. I6 engines often have two, V12 sometimes 4.
I have observed it applying 4 different levels of retard on 4 different cylinders as indicated by 4 LEDs illuminated. If 1 to 4 cylinders have the same retard you only see 1 LED. You can also set the J&S to apply global retard on all cylinders.

The pressure switch is a Hobbs switch that was left over in my Aquamist 2c kit and the SW is a standard feature of my Emerald K3 ECU. It works from a analog input. It tells the ECU to switch maps past adjustable voltage threshold. The rest is a resistor across the switch and a internal pull up resistor :-)

I will surely send him a message, if you want I can put you in my reference for your good name.

Cheers