NefMoto

Hello,

i have a question about CF timing.

i'm using stock timing map. my boost is 1.4bar and wot AFR 11.5s. actual timing looks like as 11-12degree on vagcom. @6500rpm

But my CF values higher than 6... some times 7.5... how do i tune correctly ? i don't want reduce timing advance.

may be due to wrongly scaled maf ? or high pressure... ? wrong tvub ? or none , is it normal.. you can go to reduce timing.. or going to meth injection...

I'm confused...i don't want to see bigger than 3 CF..

my ecu is motronic 3.83 i know most people doesn't have a information about motronic 3x. but it something similar with m7x..

How can i reduce my CF's ? ( i don't want touch knock sensitivity maps)

Thank you

Kind Regards,

Why? You are at the knock limit.

The primary way to reduce knock is by pulling timing, which is what the ECU is already doing for you.

If you don't want to lose timing, you'll have to pull boost, enrich AFR, increase octane, decrease IAT, etc.

If you pull a bit of requested timing, you may actually get some actual back by having lower CFs.

what's your CFs ? what's the optimal values ? bosch recomended..

also is this situation related with wrongly tuned maps ? for example i have  a stock TVUB map. and i'm using 3" maf housing with oem maf. 1x256k maf had been rescaled % increase.

I know these suggestions. but  i want to sure from my tuned maps. i know, there is a no more people's about motronic 3x..  :(

Thank you.

Honestly, 7 isn't terrible. You wont have any issues if you stay there.

If you get them below 5, you might see better timing (yes, pulling timing might get you more timing)

Just make sure they're >0 and you'll always be getting optimum timing for conditions/fuel.

You've increased load (boost) without modifying your timing map.  This means that you're likely pushing load values into the 200's, while utilizing a stock KFZW with an axis that maxes out at 150.  This means your timing is specifying values that would be normal at a load of 150% but insane at a load of 210%, thus the ECU retards timing heavily.

yes correct!, but when i looked 6-7 degree retard, my actual timing going to 11s.. and the car is very lazy.

please find attachment. you can look at quick log.


Thank you for your comments

Yes, exactly.. I suspect it. but i don't have a any idea how can i scale it ?  Can i recale Y axis to 12ms's . but i think this is can be very dangerous. and i never seen good tuned KFZW map on motronic 3x.(with axis scaled)


also i think it's might be maf scaling.. if engine load calculated wrongly, i'll see abnormal retard values.. but i don't know How can I be sure, i made correctly scaled ?


Thank you for your comments

Timing corrections are coming from the readings at your knock sensors.  I wouldn't confuse this with a scaled MAF. 

I'm not sure I know of a good way to scale KFZW.  Maybe someone else can offer insight into this.  In my case, I borrowed the KFZW from a TT225 and scaled it back about 5-10% because I believe the TT uses a different crank.

It's pretty simple, you are running too much boost and timing for your setup.
If you were tuning a standalone without amazing knock control like Motronic has, you would have melted your engine by now.
If you continue like this you will probably damage the exhaust valves and possibly the turbocharger due to huge EGT's.

Think a bit about this.

Tuning an internal combustion engine is not like playing need for speed. There are physical processes behind things, and it is a very good idea to understand them, before making changes to the engine management!

An AFR of 11.5 seems to be rich to me, so this point of enrichment against knock isnt possible anymore imo.

All in all I agree with the others. Reducing boost is the main thing.

A small improvement:
Perhaps you can switch to better fuel with higher ron roz aon (depends where you come from.) And go down with the "Heat-Value" of the spark plug (sorry for my bad english :D).
If you drive e.g. a NGK XXX 6 XXX, try a set of XXX 8 XXX. At NGK, the higher the value, the cooler the ignition. This reduces knock. Nippondenso goes the same way...
Attention:
Bosch spark plug values go the other way. The higher the value, the higher ign the temp.

Depends on the engine, some make the most power as rich as 0.75 lambda.

But VAG 1.8T's tend to make most power at about 0.82-0.8, going richer to about 0.77 if advancing timing as well, does not tend to hurt performance, anything richer than that starts hurting performance even with advanced timing.

Of course this is speaking about a fairly stock engine...

He just needs to fix his load axis on KFZW.

And rescale the values I assume?
Is there other axises which should be generally scaled on ME7.5?
I´ve already scaled the KFZWOP(/2) axis and values to match the rescaled KFMIOP (for raised KFMIRL).
KFLBTS should be fine with the original load axis as it is rich enough @ 150%?

That will accomplish nothing. On contrary, if you only scale the axis you will advance timing all over the place.
The existing data needs to be consolidated, more range added and the top end needs to be filled in correctly.

But you are assuming this is somehow his problem, when it's not. He is on M3.8, not ME7.

I don't know why you guys are talking about KFZW/OP, KFLBTS, KFMIOP and what not here. There is no torque model in M3.8.

I do not get the reference that my friend, because TT225 has a me7x ecu.


Yes,right.. i'm reading bosch engine management documents etc..
i'll try reduce a bit ignition @highloads.





i had a 12s and i don't have a any problem. but fuel quality big factor for good timing. therefore I went back to 11.5s. i'm looking all situations..

I have a NGK 7x spark plugs. i think 8 more extreme for my setup. :)

Yes we don't have a any information about motronic 3 torque model and management..Nobody does not share information.longer an old ecu.. very interesting...

I think, talking about it.

i did rescale KFZW map X axsis. please find in attachment. just change, i changed map offset & factor value. old value 0.050000 new value is 0.060000.. correct or wrong.. it just example.

now it's going to 12ms load. But now advance timing all over the place. it can be dangerous. we need good tuned KFZW map or engine torque model... I have not seen a axis scaled KFZW map...

The summary,

CF's not good and not bad. but it maybe better.

physical factors can reduce it .. low iat,high octane,meth injection etc.,colder sparks,coilpack upgrades..We all know it.

it can lead to incorrect tuned maps ? load request (Kennfeld LDR-Sollwert,Linearisierung der Heißfilmspannung, etc) or fueling.. ?

i cannot see fuel trims on my me3x.. therefore I can not find the reference and can not be sure.


I think the topic would be helpful for everyone.


Thank you for all the comments.

Regards,

 I think, if you have the cf´s high, with scaling the axis like this without changing the ign angle, you will get more probs.

I would have taken at least the same vales for the same load as before and for the 12ish load, build a complete new retarded ign. angle row.

There you could log and test if this worked, without any danger.

when you change axis values.. yes, you will have a more probs... but against values higher than original values..

Can you please look at my attachment. @ 6ms engine load x 5000rpm.. Old ignition angel = 29.25 new ignition angel is 36 !!
Automatically i will see advanced timing all over the place...approximately 7 degrees  :o

But lastest maximum engine load values same as original KFZW.i think we should be reduced middle load rpm timing area.. i'm not sure for this changes...

Do you have tried this before on motronic m38x ?

Oh, correction:

This is what I meant.

By changing the axis data, the ignition will be much too advanced.

You have to change / bring them into the right place again...

So you should divide all values through 1.2, and then you should be at the same level as before.
After that you change the timig after you logged again, if necessary.

@ all others, correct me if im wrong. Didnt try this yet :D

Pro tuning :P

Sorry, I just found it funny. I think a bit more work needs to be done than this :)

I didnt say it would solve all his probs with cf.

But after changing axis, he will get by doing this, to the point he was before.
But with the advantage, to have a better resolution.

Or do you mean, that axis changing generally doesnt work on here?

@PRJ

Could you please tell us ? how can we change this map ?

How you can change these maps?

Buy this:
http://www.amazon.com/Induction-Performance-Practical-Supercharging-Turbocharging/dp/1859606911 (http://www.amazon.com/Induction-Performance-Practical-Supercharging-Turbocharging/dp/1859606911)

And this:
http://www.amazon.com/Designing-Tuning-High-Performance-Injection-Systems/dp/1932494901 (http://www.amazon.com/Designing-Tuning-High-Performance-Injection-Systems/dp/1932494901)

Read both, understand them, then you will probably have an idea of how to do things.

Hi PRJ,

Reading your posts, gives me the idea that your have worked on this kinda ecu before.

I have a small question related to the topic.

Is it correct that this map (screenshot) is responsible for the main/fullthrottle ingition and needs (also)tuning to sort the issue ?

Thanks for your efford,

Cheers,

PvL

your load axis looks very different to what I see..
sure its right?
I have 10-150 on a 150bhp AUM Golf engine in comparison

it's motronic 38x my friend. not me7x

If only I could remember. I tuned this long ago and I was finding the maps by hand without DAMOS.
But M3.x is very similar to old Motronic (M2.x, M1.x) the main difference is that it has a 16 bit MCU.

Yes, that is the correct map for ignition angle, there are probably one or two more next to it that should be tuned initially to see which one responds.  You shouldn't be changing the load axis unless you are exceeding 10ms/stroke of load.

Rick