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Discussion Starter #1
Hi all!

Excuse for mine bad English:
I read about systems of an injection and much features of their work, thought much …
I in target have conducted experiment. I have entered into the circuit(scheme) of the gauge of oxygen sensor silicon diode (in Russian named - 2C107A - cost - $ 0,06).
All modifications are drawn on my pictures by "red" colour.

Outcomes of tests:
1) Dynamics(changes) of dispersal was improved, now even in cold weather the engine gathers better turnovers and there are no falls for want of sharp pressing a pedal of gas.
2) For want of dispersal " a pedal in a floor " the drive faster reacts and faster is boosted.
 

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Makes you wonder how dumb we sound when speaking French or Spanish, etc. lol :) no offense though, English is supposedly a hard language :eek:
 

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Alexander,
you are clipping the o2 sensor voltage at .7vdc ,does this give you a better response ? does it run rich at idle (closed loop) ?

What part of performance are you trying to improve ?

Frank Martin
 

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Discussion Starter #4
KORMEX said:

you are clipping the o2 sensor voltage at .7vdc ,does this give you a better response ? does it run rich at idle (closed loop) ?
What part of performance are you trying to improve ?
Frank Martin
1) Yes, clipping the o2 sensor voltage at .7vdc, I'm have better
response. My car can more acceleration and more quickly increase rpm's if I "go fast start".

2) In idle do not have "rich", because o2 sensor have output ~0.1V-0.25V. It's below "clipping voltage", therefore mixture is not a rich. It is all precisely it is visible if to connect in parallel to diode the voltmeter.

3) What part of performance ? :) I'm trying increase "start from a place", Dynamics(changes) for want of overtakings and transposition in the street daily traffic.
 

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Discussion Starter #5
Alexander said:
Hi all!

Additional info:
I provide diod "in russian" named - 2C107A (or KC107A).
His name: "stabilitron".

2C107A have analog in the "outside Russia" named: STB1
Parameters: U_stab. = 0.7V, I_work. = 0.1A
 

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Discussion Starter #7
eyebrowski said:
would this only work on a sohc?
-Greg
No, it work in ALL ECU-controlled :) cars, because phisical
processes are identical.
 

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thats what i thought, but the title "Increase power on SOHC engine" kinda threw me off. has anyone else done this? do i risk damaging anything? thanx
-Greg
 

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Discussion Starter #9
eyebrowski said:
thats what i thought, but the title "Increase power on SOHC engine" kinda threw me off. has anyone else done this? do i risk damaging anything? thanx
-Greg
NO ANY RISK ! :)

This is a O2 sensor soft voltage clipping. It's NOT a "risk" procedure.

See my pictures again for details.
 

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You clip the voltage at the Z rate of the diode. This meakes the ECU thinking that it has not enough fuel. The result is that the ECU tries to richen the mixture and therefore more fuel (and when is it too much fuel ?) will be injected. Some more fuel is good but we dont' have this under control with the O2 fooling version of the mod. This works better with an A/F controller that simulates more air and the O2 can still be read like it is. The O2 fooling method often leads to higher mpg and even darker tailpipes. The airflow-fooling version is more controllable.
 

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Discussion Starter #11
Roger G. said:
You clip the voltage at the Z rate of the diode. This meakes the ECU thinking that it has not enough fuel. The result is that the ECU tries to richen the mixture and therefore more fuel (and when is it too much fuel ?) will be injected. Some more fuel is good but we dont' have this under control with the O2 fooling version of the mod. This works better with an A/F controller that simulates more air and the O2 can still be read like it is. The O2 fooling method often leads to higher mpg and even darker tailpipes. The airflow-fooling version is more controllable.
Not a true ;) (about darker tailpipes...)

In fact, in order to get maximum power from the engine, you have to make sure to keep it cold. In fact, even running the ideal 14.7:1 air/fuel ratio under high load, high RPM conditions can be a very bad thing for your engine. You want to make certain the engine runs cool enough to prevent it from self-destructing.

One way of achieving cooler temperatures is to inject more fuel into the cylinders. This extra fuel acts as a coolant, reducing combustion temperatures. The cooler temperatures also reduce the possibility of the air/fuel mixture igniting in the cylinder before the spark plug is fired, a condition called 'preignition' or 'knock'. This lets the engine controller advance the timing on the engine, resulting in more power.

To achieve this cooling effect, the programmers of the DSM ECUs decided to program in very conservative values for the required amount of fuel, which guarantees the (stock) engine will run safely no matter how hard the car is driven. As a result, the ECU is only concerned with delivering enough fuel to each cylinder - how much more than enough is not a concern.

To this end, the ECU still determines the amount of fuel to deliver from the signals delivered by the MAS. Because the engine is under acceleration, however, the fuel quantity selected by the ECU is larger than before. Also, since the fuel amount is guaranteed to be enough (by design), the ECU no longer checks the oxygen sensor to see how close it was to the 'correct' output. (The signal is still there - the ECU simply doesn't bother doing anything with it.)

This failure to check the oxygen sensor for sufficient fuel is the difference between open-loop and closed-loop operation.
While under 'normal' conditions, the ECU checks the oxygen sensor for the results of its own actions - monitors the feedback, in other words. While under acceleration, the ECU does not use the feedback information, and is 'demoted' to open-loop operation for the duration of the acceleration period. When the acceleration ceases, the ECU returns to closed-loop operation once again.

While running in open-loop operation, the ECU is designed to provide an air/fuel ratio of about 11:1; less air, more fuel. (This will change somewhat with RPM and airflow, but that's close enough at the moment.) This is well above the switch point for the oxygen sensor. Consequently, the oxygen sensor remains fairly constant during open-loop operation, on the rich side. Viewing the signal with a voltmeter or air/fuel ratio meter will show a very high, relatively steady oxygen sensor output, in contrast to the 'bouncy' signal seen during closed-loop operation. This signal is normal and, in fact, eminently desireable - the higher the better (to a point).

So how does the ECU decide when 'normal' conditions exist and when 'acceleration' conditions prevail? The primary trigger that switches the ECU from one control method to another is a simple lookup table, which compares throttle (accelerator) position against engine speed. These signals are both provided to the ECU from various sensors in the engine.

Closed loop operation occurs when the engine is idling, or running at near-constant throttle position at near-constant engine speed. During idle, the ECU actually has two goals: one, to deliver the correct fuel, and two, to maintain the idle speed at 750 RPM. The fuel is handled by controlling the injectors and using the oxygen sensor for feedback. The idle speed is controlled by the idle speed control motor (ISC), using the crankshaft angle sensor as feedback.

Relatively large changes in throttle position at a given RPM will cause the ECU to change to open-loop operation. Once the throttle position and RPM are back "in sync" with each other, the ECU will generally switch back to closed-loop operation. This can occur if the throttle position moves again, or if the engine speed begins to level out at the new throttle position.
 

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HOLY UKRANE BATMAN!!!

What happened to the bad english!
 

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Did you get someone else to type that, or you just decided to learn English in a day? It almost sounds like you used bablefish or something like that at first, no offense. That was very informative. I'm confused, though. Did the diode railing at .7 volts in the O2 line help or not?
 

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Discussion Starter #14
QuonoS said:
Did you get someone else to type that, or you just decided to learn English in a day? It almost sounds like you used bablefish or something like that at first, no offense. That was very informative. I'm confused, though. Did the diode railing at .7 volts in the O2 line help or not?
Essentially helps.
I go with such system(device) already more than week.
Now I conduct samplings spent fuel for want of movement(traffic) in town cycle (start-stop-go!...).
 

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Alexander, I know the explanation you are telling us for many years now ;)

In fact too much fuel is a bad thing and coolign the combustion chamber with fuel is a very bad idea. Yo uwill wash out the walls and much more carbon deposit will be the result. And you know that hot crabon deposits are often the cause for self ignition.

As it seems that you know the internal ECU's behaviour I wonder why you just don't remap it ? Also what do you do to the different fuel maps.

You are telling us the correct stuff although it's basics for every feedback controlled car. But it stands in opposite to the trick you told in the beginning. Fooling the ECU by lowering the O2 signal will result in an effect in closed loop operation. In open loop the fuel value is determined by the TPS,air flow signal (equals Load)and rpm. Therefore the Diode mod does ... nothing :) Any more power you feel is butt-related and also related to the ECU that has not determined the offset-variable for the map (e.g. when disconnected the battery). When the ECU learned, everything is back to normal.

As said, only a fuel controlelr (i.e. airflow signal tweaker) helps but even then the ECU adapts over the period. Therefore it must be compensated often for the additional fuel one wants.

Last thing, the NA's engines are not a problem heat-wise, absolutely not. It's another story in our TT engines for sure !

Get a datalogger and check out what works in our engines (like fuel enrichment values and so on)
 

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Discussion Starter #17
Dear Roger !

I simply ascertain the fact:
After introduction in the circuit(my scheme) of the diode mine (SOHC, "Calofornia ignition") Stealth has become more dynamical.

Yes, I know that is necessary to reprogram ECU, but nobody hinders me to put experiments. :)

All this can because of that what in Ukraine sell off-standard petrol?
:confused:
 

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Discussion Starter #18
To all:

I don't have datalogger :(

In Ukraine "engine tester's" is very big problem.

I this time I have Palm m505 and I want to find a possibility to purchase and to transmit myself the necessary software and parchcords.
 

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I think he cut/paste an article off of another site in that reply, don't think he wrote it originally. :D

Ted
 
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