Did some data logging on my MY00 STI V6 ( same as the P1 map im pretty sure) ( Jap Spec with TBE only mod) the other day using ECU Explorer software.

Can someone please clarify something for me.

1. In the Knock Correction column and when the engine is under positive psi i get a column of
-1's and -2's. From what i gather, does this means the ECU is pulling out 1 -2 degrees of timing BTDC from the "Ignition timing" column value? i mean is the ignition timing column the true timing run by the engine? or is it that value, minus the -1 or -2?

2. Is the ECU pulling another degree out of the "Ignition timing" column value every time? i mean if i have 4 x -1's in succession, does this mean the ECU has pulled 4 Degrees from the "Ignition timing" value?

3. Also since adding the exhaust (and adjusting boost back to the same peak about 15.5 psi) boost comes faster at lower rpm. Now i see -4's and -5's. Is this because my new torque curve (higher boost @ lower rpm) falls outside the base maps active timing parameters and the ecu cannot save the reduced timing values its pulling out? i mean it keeps showing -5's but wont save the reduced values for next time so it wont have to, but it never adds it back later....if im making sence.

4. What is the max you guys have seen pulled by the JECS ECU? is this safe, i mean what my ECU is doing?

I run the car on 98 octane. My AFM is new, AFR's are super rich at 0.72 lambda full load. Knock link lights up2 green, 2 orange on most sensitive setting, never red.

Its not a fuel supply problem, im just baffled as to why the ECU wont save the retarded values and goes into -5 in the same area of the map ever time.

5. The lowest ignition timing value displayed is 28* as load reaches max. What do you guys see?

Someone please shed some light on this for me.
Cheers

 

I think you might stand to get a better answer from chatting with one of the many tuners around. Alternatively, 22B BBS tends to be more technically focussed than Scoobynet.

J.

 

A few things here:

1. The AF040/041 JDM STi ECU is not the same as the AG340 P1 ECU.
2. Have you reset the ECU and taken the car out, listening for det whilst datalogging?
3. The ECU will learn the amount of timing it is pulling in certain areas of the map and store it in the learned ignition correction table, but your logging will continue to show the total correction from the ignition advance derived from the stored maps.
4. 4 x -1 in successive logs means that the ECU has pulled 1 deg each time, not 1deg, then 2, then 3, then 4.
5. What's your Advance Multiplier?
6. What Engine Load/MAF Voltage are you seeing at full chat?

Andrew...

 

I've used ECU Explorer to check my MY00 every now and then or if I think there may be a problem. Originally it was PPP with extra sports cat downpipe and I would get up to -7 knock correction if flooring it in 4th at 4000rpm. Now I have 300 ish BHP with extra mods and it's pretty much the same. As boost rises there is a lot of compensation from the ECU for fuel/ ignition etc.
What is important is that when the boost stabilizes the knock correction you are seeing should drop to 0 and stay like this until next gear is taken. If you see knock correction throughout the same gear with throttle and boost constant then this would point to a mapping problem/ fuel octane to low or an engine fault. I find usually on ECU Explorer with my car the knock correction reduces to 0 after around 6-ish lines on the log.
Kevin

 

Just checked an old log. Log is full bore through 3rd and then into 4th up to about 120mph. The knock correction shows at the gear change with throttle and reads -3, -7, -2 and then returns to 0. The ignition timing is around 28 degrees at this point however it goes down as speed increases in both gears to a low value of 12 BTDC. Front O2 sensor reading (there is of course only one sensor) is showing as 0.9 volts or just over at full throttle/ boost in both gears.
Kevin

 

As Andrew mentioned, what's the IAM (Ignition Advance Multiplier).
It's not on the list for MY99/00 ECU in ECUExplorer but it is available when you finally pick/find the correct address from the user defined option.

I did find it with mine when messing the other week, but it's on the lappy.

It should be between 0 and 16. 16 being the preferred value which means you have full ignition advance available.
If it's around 12 don't worry about it.

I'm not sure what the MY99/00 ECU defaults to after a reset. The MY01> defaults to 12 then tries to advance to 16 if possible.

standard 02 sensor isn't worth monitoring

 

My AM is on 15 and hasnt moved, hit 16 for a moment then just sits on 15 even with the -5 knock retards.
Airflow sensor hits very close to 4.4V full rpm/load. I renewed it also 3 days ago, and like i said my AFR's are factory way rich...10.6 on full load/boost, so im sure its not a fueling issue.

 

I wouldn't worry about it if the IAM is on 15.
Fuelling sounds spot on for stock ECU.