Low ignition timing at idle 25DET NEO

[RICE RACING]

 

Edited March 5, 2019 by RICE RACING

[dr phil]

Ok I don’t think it has a map for this, probably has an equation about how to alter timing based on actual idle speed vs target idle speed. But from a log of my car it seems to jump around from 3 deg to about 13 in normal conditions, at idle, with the throttle closed.

[Slap]

That is similar to what i thpught... i thnk.

So to clarify. I see 30° from the light this is total/absolute timing?

Does this mean if im at 15 ° crank then the ecu is adding 15° to make it show as 30°?

Lets get trickier just to spice up the mix now we can see a few things

I advance my exauhst cam 7° and retard my inlet 2-3°.... we know the inlet wont impact timing much exept a bit of extra jitter.... the exausht cam will now have advanced the cas 7°... cas needs correction....flame front to turbine with rich 02 sensor now raising the exauhst temps(light only stock)......now the ecu has to correct its tune by 7° to the zorst valves and o2 how?

[dr phil]

No if you are seeing 30 from the light you are doing something wrong. Please stop thinking the ecu has a base timing amount AND an amount that it adds. It does not. It only operates on total. If the ecu shows 15, you should see 15 on the light. If the ecu shows 3 YOU SHOULD SEE 3 ON THE LIGHT. It runs low total timing at idle for the reasons I explained.

/thread

[Slap]

But now like someone said earlier the car may not be droping back to an idle map because maybe it cant cope on it or get the car down to it.

 

And geebs im not sure if you guys are trying to confuse me.

 

1 moment you say it can to an extent then say no you cant.

 

If i set it locked to the 15 with tps off and then reset my ecu why does it now say 30 tps on. And do it again over a few times. I have also tried running both advance and underadvance on the cas only to see it back at 30° on the light again. Tell me what i have done wrong?

 

 

[dr phil]

When you see 30 deg, what rpm is the engine running at? It sounds like it is in overrun timing not idle control.

Also you should verify your TPS is adjusted correctly, it should have less than 0.5v on the signal wire with throttle closed.

[dr phil]

Oh, and dont forget the idle screw, with TPS off, timing at 15 on ecu and light, you adjust the idle speed to 650rpm with the idle speed screw (engine warmed up). That and the TPS voltage are important.

If you can’t achieve 650rpm at 15deg timing you have a problem that needs to be fixed.

[Ben C34]

What ever the ecu is commanding is what should be seen on the light. As has been said. It's  that simple.

 

[Ben C34]

Slap you are missing some fundamental basics here. The ecu can't correct for the cas being set in the wrong position, like in your advancing the exhaust gear example, that's up to you to set the cas in the correct spot. The inlet cam jitter thing doesn't make sense.

Flame front to turbine? What?

[Ben C34]

And you would typically retard the exhaust and advance the inlet for more power.

[Slap]

Sorry i should have explained better but rushed.

 

1st i cant change the cars setup atm because i need to get some lifters after the rebuild its had.

 

2nd i have done it the correct way you say about setting the timming.

 

3rd i set my idle to 850 even if i wasnt ment to.(loved 850 rpm)

 

4th i did mean manual corection of the cas and then was explaining that the flame front will jet power the turbine due to the exauhst valve advance inturn the o2 will read richer because the fuel hasnt fully burnt as it was released earlier also the exausht temp indicator may come on if its to much - wich means that then it will need to either be spark advanced or fuel reduced to correct the flame front enough that the o2 and the exauhst temps are good or even both.

Meaning:

less fuel used at idle

Quicker more powerfull spool up with hard hitting midrange rpm torque and good top and bottom end power. Weapon!

 

5th the inlet cam causes a lil belt jitter i say because now the belt will have less tension between the cam gears i believe.

(Maybe?)

 

6th the inlet cam gets retarded a tiny bit because it doesnt do much compared to the exausht cam gear but a little bit will help the head flow quicker by (i think increased valve overlap) also helping cooling, reducing compression slightly and allowing a speedy passage to the turbine and boost should build quicker .

 

7th i have the safc wired up so i can watch airflow and i can change it. I cannot monitor the throttle atm but it was fine when i could before i boost refrenced the throttle load axis.

 

I will try to keep things short and sweet from now on as that was a fair bit for one post just to try clarify

 

And by the way the car ran sweet af until i got drunk and let a young bloke do a skid and he pinged it and held it flat past 9500 rpm in fisrt on a down hill(wanker). Oil starved and spun a bearing wich ive rebuilt the motor and now waiting for cash for lifters.

 

 

 

 

[Ben C34]

1 hour ago, Slap said:

Sorry i should have explained better but rushed.

 

1st i cant change the cars setup atm because i need to get some lifters after the rebuild its had.

 

2nd i have done it the correct way you say about setting the timming.

 

3rd i set my idle to 850 even if i wasnt ment to.(loved 850 rpm)

 

4th i did mean manual corection of the cas and then was explaining that the flame front will jet power the turbine due to the exauhst valve advance inturn the o2 will read richer because the fuel hasnt fully burnt as it was released earlier also the exausht temp indicator may come on if its to much - wich means that then it will need to either be spark advanced or fuel reduced to correct the flame front enough that the o2 and the exauhst temps are good or even both.

Meaning:

less fuel used at idle

Quicker more powerfull spool up with hard hitting midrange rpm torque and good top and bottom end power. Weapon!

 

5th the inlet cam causes a lil belt jitter i say because now the belt will have less tension between the cam gears i believe.

(Maybe?)

 

6th the inlet cam gets retarded a tiny bit because it doesnt do much compared to the exausht cam gear but a little bit will help the head flow quicker by (i think increased valve overlap) also helping cooling, reducing compression slightly and allowing a speedy passage to the turbine and boost should build quicker .

 

7th i have the safc wired up so i can watch airflow and i can change it. I cannot monitor the throttle atm but it was fine when i could before i boost refrenced the throttle load axis.

 

I will try to keep things short and sweet from now on as that was a fair bit for one post just to try clarify

 

And by the way the car ran sweet af until i got drunk and let a young bloke do a skid and he pinged it and held it flat past 9500 rpm in fisrt on a down hill(wanker). Oil starved and spun a bearing wich ive rebuilt the motor and now waiting for cash for lifters.

 

 

 

 

I'm out...

that has way too much nonsense to continue. All the best man.

[Slap]

I'm out...
that has way too much nonsense to continue. All the best man.

Thats fine you dont have to be involved.
The only nonsense would be the possibilities of the jittering belt cause i am unsure of that.

Thanks though for being reasonable to me now.

[Slap]

This is also wrong..

"
6th the inlet cam gets retarded a tiny bit because it doesnt do much compared to the exausht cam gear but a little bit will help the head flow quicker by (i think increased valve overlap) also helping cooling, reducing compression slightly and allowing a speedy passage to the turbine and boost should build quicker ."

As i ment less overlap but mixed them up.

[Slap]

Here is a link for any one interested in what i said. And how to tune cam gears.
I cant explain shid like this but wish i could.

https://www.hamotorsports.com/cam-gear-tuning.html

[iruvyouskyrine]

is Slap the new la bomba? 

[Dose Pipe Sutututu]

This is pretty much how idle stabilisation works, you have an idle/decel table which dictates the base idle ignition timing, then there's another table which adds in timing or deducts from the 15 degrees of timing to reduce or increase torque to allow the motor to hit it's target idle, which is dictated in the idle target table.

This is as close as it gets to the OEM ECU, I don't like the way it's done via Nistune however it works. 

A much simpler, more elegant way is using a RPM error table, such is available in plenty of mainstream ECUs such as kebabtech (queue the haters but I like using it).

Here's the stock timing table, you can see that all the idle cells are 15

And here you see there's an idle timing correction table for when the idle rpm is not met

And don't forget there's ignition timing added to warm up the motor too

 

So yeah your "base timing" might be 15, but when you start layering on addition dimensions for idle control strategies, engine operating temperature strategies it can easily swing up and down. That is why when you're setting your CAS you need to lock your ignition timing, so regardless of inputs/compensation tables applied the timing will be fixed.

e.g.

[RICE RACING]

Not Halaltech but description in the interests of learning/teaching.

 

[Kinkstaah]

This thread is a perfect example of "If you want information, go online and post the wrong answer"

The rest of the answers from everyone except OP are pretty goldmine-esque.

[Lithium]

Oh my god, I'd heard about this thread and for some reason decided to have a look.   Kudos to the people who have tried to help, @Slap... I say this not to be a hater, but to try and help you.   You really have so many of the fundamentals quite quite wrong, please slow down and listen, think and research a bit more - you are sprinting with scissors through a minefield blindfolded and it's scary to watch.

Edited March 5, 2019 by Lithium