PIII ignition retard

[JohnA]

At what stage does the ECU start to retard during prolonged full throttle?
I'm talking about an LET with the EDS i/c and 20psi overboost

Just a rough approximate figure would do, say with ambient temp at 20C

 

[GSI-TURBO]

As far as i know it is using a fixed table..

If not.. please let me know..

Regards,

Dennis

 

[JohnA]

I was under the impression that this board is frequented by EDS, a company that is supposed to know what they're doing.
But I don't see them responding at all - I wonder why I bothered to log in here at all... :roll:

 

[GSI-TURBO]

Hi JohnA !

I made some tables from the standard and ph3 tables, and the ignition is NOT retarded, is is even a little advanced.

The big difference compared to the other phases is the fuel table which is adjusted to the higher fuel pressure.

I hope i don't get into trouble with this information.

Regards,

Dennis

 

[JohnA]

Yes, but surely if temperatures go too high it will cut down boost and retard the ignition a bit...
Worst case, say there's knocking - is it not going to retard?

 

[Samy]

No the Boost will cut down if the Lambdacontrol reads too low voltage from the sensor. On the pcb of the phase3 - phase4 boost control electric are no temperature input. The ignition will retard when its knocking.

 

[JohnA]

Thank you Samy

Despite the title, it's not exactly a PIII setup that I'm interested in, but it's useful to know that PIII does not react to excessive charge temperatures.

Strange though...

 

[Samy]

not? because the threads topic is called "PIII ignition retard"
Ignition retard comes when the knock sensor detects knocking or the water temperature is to high. For the boost temperature theres a correction table in the ecu. But theres no standard retard if you go for 20psi. the ignition is in all boost levels the same, except a knocking or temperature failure is detected.

 

[JohnA]

So it's WATER temperature that it uses - my impression was that the motronic uses AIR temperature (from the sensor on the intake manifold)

 

[Samy]

yes for a correction table.

 

[JohnA]

I guess they *assume* that if charge temps are too high, water temps would reflect that.
But it you have a large boost spike the charge temps would go through the roof without the water temps going into the red for several seconds. That could cost the engine though, it's not the right approach in my opinion :shock:

 

[Samy]

the correction table is for that situation if the charge temp goes to high the ignition timing retard.

 

[JohnA]

Ah, so there *is* a correction table for charge temps.
I guess that's what I'm after! Any ideas on how to get info on that?

 

[ASH]

Hi !

Sorry for the long delay , but im very busy in the moment !

The standart EDS Phase-3 oder 3.5 System is delivered with a very big and high effitiant intercooler , so the charged air temp is also in very worse cases never to high !

regards ASH

 

[JohnA]

The standart EDS Phase-3 oder 3.5 System is delivered with a very big and high effitiant intercooler ,

compared to the stock (joke of an) intercooler, yes

compared to other intercoolers it's simply adequate


ASH thanks, although you did not exactly answer the question :wink:

 

[TURBO maniak]

Sorry for off topic but, can we assume that in the case, that we have Phase 1 ot 2 for example(0.9bar hold boost) and if we can delivery enough fuel(through additional injectors), we can reach high boost levels around 1.7-1.8bar hold boost without problems :?:
Please forget engine internals, turbo capacity, intercooler and etc. (suppose that we have proper), this is only theory for engine ECU management

I think that fueling is not BIG problem, but the ignition advance IS. My opinion is that advance in 6000rpm with 1bar boost and 6000rpm with 1.8bar boost is not the same value.
Wath are you think for :?:

 

[JohnA]

...My opinion is that advance in 6000rpm with 1bar boost and 6000rpm with 1.8bar boost is not the same value.
Wath are you think for :?:

If everything else stays the same (comp ratio, cam timing etc) and fuelling is spot on at 1.8 bar, the ignition would *still* need to be readjusted at 1.8 bar, because the speed of burn would be different (much higher peak pressures invoved and more contamination due to reversion)

One funny thing I found is that PIII cars cannot run at all if the coolant temp sensor is disconnected.
Funny that, as the motronic is supposed to have a replacement value to help you get home.
Maybe ASH can help us with this one...

 

[GSI-TURBO]

I also believe that a boost dependent ignition will be better.
But ! the motronic will retard IF you reach 1.8 bar and starts to knock, because it uses a Knock Sensor !

I am using DTA, and i have to watch out during setting up ignition, because it isn't using a knock sensor. I DO have a device to use the knock sensor on a DTA system. If it detects knock, it simply retards ignition.

The nice thing about the DTA system is that i made a table with pressure compensation. So let's say at 0,5bar boost i will run 18 degrees, and at 1,5 bar it runs 5 degrees (example) and fueling is also adjusted on water AND air temperature

Regards,

Dennis

 

[JohnA]

I...a table with pressure compensation. So let's say at 0,5bar boost i will run 18 degrees, and at 1,5 bar it runs 5 degrees (example) and fueling is also adjusted on water AND air temperature

That's a much better way of doing things

 

[JohnA]

3 months later and not a word from ASH

Talking about customer service, eh? :lol: