ECUTune, for those of you that have/had it

[Trevor]

Originally Posted by Trevor

If confirmed information is available, i.e. "Those of us who genuinely have the ability to monitor ignition retard and advance have not seen this." presenting the figures would surely close any argument.

Having had OT's select monitor in both of my SVXi many months back, I was able to view both of my car's timing. While my stage 3 was pulling 10* of timing whenever i got on the throttle My bone stock SVX was pulling timing in high load situations. Most I ever saw was 8* of retard.



There aren't any figures to present except to say that when you drive around monitoring "rtrd" and "adv" you clearly see that on a healthy SVX the factory ECU doesn't retard the ignition advance. It does the opposite. It adds ignition advance. "rtrd" is just the label for a memory location in the ecu which holds the immediate value from the translation of the knock sensor signal. A value of 8 does not mean 8 degrees of retard. It means 8 degrees of advance. A value of -8 means 8 degrees of retard. The factory primary ignition map is extremely conservative under high load to say the least; the ecu uses the knock sensors to seek out knock and add in additional advance up to the threshold of theoretical maximum advantage.



It's good to get actual figures rather than conjecture.

Tom, would you not consider it normal for the timing map to retard the timing in high load situations, given that it is a high compression engine pulling a heavy car at low revs?

With the auto box being programmed to prefer high gears and run the car between 1500 and 2000 rpm all the time, this I remember as being the range where my old 2.2 litre Matra used to pink badly under load in top.

As I see it the SVX is constrained by the TCU to constantly pull within a range that leaves it open to detonation, even naturally aspirated.



Valid figures are void of semantics. Currently confusion is the order of the day.

The existence of a figure representing retard or advance requires a baseline figure. It is now suggested that the base line is zero in respect of the figures presented. Does this align with the piston at top dead centre. If not what is the basis of zero?

Please, can the term “Pulling” be avoided in the interests clarity and accuracy.

[Nomake Wan]

Originally Posted by svxistentialist

Guys, before we lose the run of it here we should consider carefully where this "300hp" suggested figure is coming from, and not presume there is a hidden and untapped 70hp sitting around waiting to be discovered. Because plainly, this is nonsense.

PS When YT is talking about timing getting pulled, I think he is referring to the engine with supercharger and no charge cooling in place. This is a different kettle of fish from a stock engine.

http://www.subaru-svx.net/forum/show...39&postcount=1

PS http://www.subaru-svx.net/forum/show...&postcount=611

[TomsSVX]

Originally Posted by longassname

There aren't any figures to present except to say that when you drive around monitoring "rtrd" and "adv" you clearly see that on a healthy SVX the factory ECU doesn't retard the ignition advance. It does the opposite. It adds ignition advance. "rtrd" is just the label for a memory location in the ecu which holds the immediate value from the translation of the knock sensor signal. A value of 8 does not mean 8 degrees of retard. It means 8 degrees of advance. A value of -8 means 8 degrees of retard. The factory primary ignition map is extremely conservative under high load to say the least; the ecu uses the knock sensors to seek out knock and add in additional advance up to the threshold of theoretical maximum advantage.

This statement is 100% correct. The SSM RTD function will only show anything but 0 when the knock sensors pick something up. I am saying that the problem is, even on healthy stock SVXi it is not uncommon to see that the ECU does retard timing from the advance due to knock detection. I am sure there are cars that this will never happen on, but there are indeed, very healthy EG33's that this apparent in. That being said, I agree that a healthy SVX shouldn't do this, to coincide many infact do. The problem being that the ECU will pick up what more than likely is not knock and reduce the advance accordingly.

To my limited knowledge of the inner workings of the ECU, I do not see the sensitivity being able to be adjusted w/o comprimising the RTD function of the ECU all together.

Tom

[longassname]

Originally Posted by Trevor

The existence of a figure representing retard or advance requires a baseline figure. It is now suggested that the base line is zero in respect of the figures presented. Does this align with the piston at top dead centre. If not what is the basis of zero?

No, as I was sharing that value is an input not a result. Just like the mass air sensor signal is translated into a "load" value used in the logic to control fuel and timing the knock sensor signal is translated into a "rtrd" value used in logic to control the timing. 0 corresponds to a sensor reading which will not result in a number of routines checking to see if they should modify ignition timing. A negative number indicates a sensor reading which may result in a number of routines reducing ignition advance. A positive number indicates a sensor reading which may result in a number of routines increasing ignition advance.

[NeedForSpeed]

On a NA engine, will lowering the stock compression ratio via pistons increase potential advance and make more net power than factory ratio and potential retard?

Will lower gearing decrease engine load and possibly allow more ignition advance; thus the performance advantage of low gears is twofold, one, faster through the rev range, two, more timing resulting in more whp?

Originally Posted by longassname

No, as I was sharing that value is an input not a result. Just like the mass air sensor signal is translated into a "load" value used in the logic to control fuel and timing the knock sensor signal is translated into a "rtrd" value used in logic to control the timing. 0 corresponds to a sensor reading which will not result in a number of routines checking to see if they should modify ignition timing. A negative number indicates a sensor reading which may result in a number of routines reducing ignition advance. A positive number indicates a sensor reading which may result in a number of routines increasing ignition advance.

[Trevor]

Originally Posted by longassname

No, as I was sharing that value is an input not a result. Just like the mass air sensor signal is translated into a "load" value used in the logic to control fuel and timing the knock sensor signal is translated into a "rtrd" value used in logic to control the timing. 0 corresponds to a sensor reading which will not result in a number of routines checking to see if they should modify ignition timing. A negative number indicates a sensor reading which may result in a number of routines reducing ignition advance. A positive number indicates a sensor reading which may result in a number of routines increasing ignition advance.

A number was originally expressed in degrees, --- "A value of 8 does not mean 8 degrees of retard. It means 8 degrees of advance."

It is now stated, --- "A negative number indicates a sensor reading which may result in a number of routines reducing ignition advance. A positive number indicates a sensor reading which may result in a number of routines increasing ignition advance."

Words are failing someone. I now must assume that no one can quote figures illustrating the actual ignition timing in respect of an SVX, as original or modified.

[Nomake Wan]

Originally Posted by Trevor

Words are failing someone. I now must assume that no one can quote figures illustrating the actual ignition timing in respect of an SVX, as original or modified.

Now, that is not very fair. I understand (or perhaps, misunderstood?) the intent of your post in correcting the wording used. To then go forward and say that "no one can quote figures illustrating the actual ignition timing" is a foolish assumption. It was one mistake, which you are now applying across the board. That's silly, don't you agree?

[Dessertrunner]

Section 2 page 95 of the manual talks about how the "Select monitor" works.
Mode F07 is Ignition timing (ADVS) says the range is 12 deg to 28 deg
Mode F21 - Knock sensor signal (RTRD says range -10 to +10 deg.

Don't know if this helps but thats what the book says. I may borrow the unit here and get some numbers on my cars.
Tony

[RSVX]

Originally Posted by Nomake Wan

Now, that is not very fair. I understand (or perhaps, misunderstood?) the intent of your post in correcting the wording used. To then go forward and say that "no one can quote figures illustrating the actual ignition timing" is a foolish assumption. It was one mistake, which you are now applying across the board. That's silly, don't you agree?

But, that is his modus operandi...

[longassname]

Yes, what I said was correct. Trevor is just once again making the false assumption that the failure to understand is someone else's and not his. He's got his head stuck thinking like the ignition advance logic is 10 lines of code rather than 500. Perhaps he should be introduced to the flowchart in Subaru's patent application.

Originally Posted by Nomake Wan

Now, that is not very fair. I understand (or perhaps, misunderstood?) the intent of your post in correcting the wording used. To then go forward and say that "no one can quote figures illustrating the actual ignition timing" is a foolish assumption. It was one mistake, which you are now applying across the board. That's silly, don't you agree?

[longassname]

Trevor,

Tell me about your SVX. What kind of SVX do you have? Have you found being a member of the forums helpful in maintaining or modifying your SVX?

Originally Posted by Trevor

A number was originally expressed in degrees, --- "A value of 8 does not mean 8 degrees of retard. It means 8 degrees of advance."

It is now stated, --- "A negative number indicates a sensor reading which may result in a number of routines reducing ignition advance. A positive number indicates a sensor reading which may result in a number of routines increasing ignition advance."

Words are failing someone. I now must assume that no one can quote figures illustrating the actual ignition timing in respect of an SVX, as original or modified.

[svxistentialist]

Guys, before we lose the run of it here we should consider carefully where this "300hp" suggested figure is coming from, and not presume there is a hidden and untapped 70hp sitting around waiting to be discovered. Because plainly, this is nonsense.

We know from various people that the tuning and timing of the engine is relatively conservative, but that does not necessarily mean that it is easy or cheap to modify the engine for more power.

Joe

PS When YT is talking about timing getting pulled, I think he is referring to the engine with supercharger and no charge cooling in place. This is a different kettle of fish from a stock engine.

Originally Posted by Nomake Wan

http://www.subaru-svx.net/forum/show...39&postcount=1

Nomake, you left out a key line in my statement, underlined above. Rally Rob no doubt has the knowledge and the expertise to retune a lawnmower for another 5 hp if he felt the need because he knows what he is about.

If you look at his list of "Bolt-ons" you will see things like Autronic stand-alone, custom headers, individual coils [6 of ] and Sti injectors [6 of ]. Plus the ability to tune it. This add-on or bolt-on extra power is neither free nor is it cheap to achieve.

Originally Posted by Nomake Wan

http://www.subaru-svx.net/forum/show...&postcount=611

And in this case I have already said that the stock maps are tuned to give advance or retard based on load and based on knock sensor information.
The key point here is whether Tom is correct when he says that the timing map "unnecessarily" pulls or retards timing under load.

Maybe somebody will have to burn holes in a few pistons until we find out just how conservative the Fuji engineers were with the timing maps.

Joe

[Sir. Nate]

still waiting on those graphs

[dragoontwo]

Originally Posted by svxistentialist

Maybe somebody will have to burn holes in a few pistons until we find out just how conservative the Fuji engineers were with the timing maps.

Or if someone had some thermocouples, you could hook up and do it without burning pistons. Alas, I don't have the means to do this...

[Trevor]

Originally Posted by Nomake Wan

Now, that is not very fair. I understand (or perhaps, misunderstood?) the intent of your post in correcting the wording used. To then go forward and say that "no one can quote figures illustrating the actual ignition timing" is a foolish assumption. It was one mistake, which you are now applying across the board. That's silly, don't you agree?

I do not agree that it is silly to ensure that statements made with reference to a technical issue, are clear and accurate rather than the reverse.

What is not fair in seeking out basic facts relative to a subject under discussion? I was not intent on correcting the wording used. I queried figures clearly indicating measurements in degrees.

However by intent I softened what could be interpreted as criticism, by suggesting that only the wording might be in error. The reply now posted has confirmed my original doubts in respect of validity.