Tuners Rejoice! Free Tuning For M4.4!

[razorx]

@tjwasiak: We do have logging. More than 50 parameters and AFR logging as well. PLS stop.

[tjwasiak]

@razorx - You have, but Midnight Caller still don't log his AFR :)

[razorx]

My Serious apologies tjwasaik,

Logging AFR is essential not just looking.

[Midnight Caller]

Ok, did three more 3rd gear pulls today, from 3000rpm to 6000rpm with the new timing.

Only 1 to 3 max. "real" knocks (BITS > 128) on each pull. I don't know if 1-3 "real knock" events are average or alarming.

Now for the good part. Max. XFALMIT was 6.25, which is a GREAT improvement from 24 yesterday.

It runs absolutely pig rich now (I used all the T-5 fueling map less the last 3 lines, which I took from the LPT fuel map). I also used WOT enrichment of 1.1 between 3600 to 4800rpm, but at 5900rpm I saw an AFR of 10, at 15PSI boost ! It's the first time I've seen 15PSI of boost on this baby ! Woo-hoo !

I'll try to drop WOT enrichment tomorrow and lower the AFR a little , because advancing timing is out of question unfortunately.

80-120km/h in about 4 seconds best time (half on straight road, half uphill - I'm doing the pulls between two bridges to get rid of da' coppers )

Now the questions :

Do you think I'm having such small timing pull because of temporary disabling adaptive knock control ?

Between two logged pulls (1-2 minutes time difference), LTFT went from 1.56 to -4.69 ! Is that normal ? Could this happen because of my pig rich condition at WOT ?

Sorry for the so many questions but maybe someone else will be in my situation and reads this, going through the same hell I am.

Thank you guys !

[Piet]

Serious tuning without AFR logging just is not possible!

You really have to get that right first before you come back to us with further questions about your tuning.

Even better is to start you own topic about your tuning issues, this topic is becoming already big enough with just more relevant, more investigational things regarding the M44

[Midnight Caller]

You are right Piet. But the idea is that some modifications could lead to other problems in other areas, and are linked to M4.4 tuning in general, not to my car in particular. That's why I was filling this topic but I guess this topic is already becoming redundant info.

Thanks for the great info you all shared !

But let me ask you a more relevant (I think) question. Is it possible to set up a parralel connection between the wideband module and the ECU, without messing up the measurements ? in short, is it possible to also log AFR with ECU AND see AFR on the gauge ? I read something about probe grounding and maybe the signal split between gauge and ECU would be measured wrong by both ? I don't know if both inputs are high impedance like a voltmeter for example...

[Piet]

Just start you're own topic about this.

I'am sure enough people here will help you there and enough people will read it and learn from it.

Your issues have more to do with tuning in general then with the modifications of the M44 we're discussing here.

[Midnight Caller]

You are right, Piet. I am a moderator on another forum and even if I know what messing a topic up means, I was doing the same mistake here. Sorry, got carried away.

[Piet]

Doesn't matter, we do like enthousiast Volvo DIY tuners :)

[Johann]

I can use higher octane fuel, yes, but as you in the US (with 92RON) managed it, why wouln't I on 95RON ?

Don't know where you got that information but US doesn't use 92 RON. Mostly used I think is AKI 91. RON 95 more or less equals AKI 90. AKI = RON+MON/2. Most RON 95 have a MON number of 85, some 87.

Apparently burns a bit different due to the wider variety of Ethanol percentage added. AFAIK most Euro RON95 has 5% Ethanol added unless labeled as E10.

As Piet uses to say, the US BS HP numbers don't apply to Euro's. And this is true. Throw in a tank of Euro gasoline and the US spec high power cars suddenly aren't so high power anymore on Euro load Dyno's.

Another thing. When using a LPT 9:1 compression mostly stock Volvo engine running RON 95 octane you will run in to trouble near 0.9 bar of boost. Under ideal circumstances it could be stretched to 1 bar but you will run in to knock somewhere eventually. RON98 can stretch it a bit further but 1.1 bar will basically be it.

[venderbroeck]

Johann,

Do you know what the ethanol content in the "blue one" fuel is from the "de Haan" gas stations?

I'm seeing less knock on my bone stock 15g setup with that fuel.

I'm wondering if this is just happenstance because of varying driving circumstances, or because of the elevated ethanal percentage in that type of fuel.

In other words, is the ethanol percentage high enough to make a discernible difference?

[Johann]

http://www.blueone95.nl/index.php/milieubewust

[Midnight Caller]

Another thing. When using a LPT 9:1 compression mostly stock Volvo engine running RON 95 octane you will run in to trouble near 0.9 bar of boost. Under ideal circumstances it could be stretched to 1 bar but you will run in to knock somewhere eventually. RON98 can stretch it a bit further but 1.1 bar will basically be it.

Thanks a lot for the info about the gas ! As I've read in several different places, they said US gas was lower in octane numbers than EU spec. I guess they were BS-ing.

So if I read this correctly, on an LPT engine, almost no matter what I'll do ECU-wise (retard ignition, enrich fueling), I won't be able to run more than 1.0-1.1bar of boost without knocking ? Is this correct ?

[German850R]

Thanks a lot for the info about the gas ! As I've read in several different places, they said US gas was lower in octane numbers than EU spec. I guess they were BS-ing.

So if I read this correctly, on an LPT engine, almost no matter what I'll do ECU-wise (retard ignition, enrich fueling), I won't be able to run more than 1.0-1.1bar of boost without knocking ? Is this correct ?

Nono, you are right. US gas, especially California, is rubbish. What we have as 95 octane usually has 5% ethanol content but you can also buy E10 with 10%. Do you have that in Romania as well?

Please try a little bit better fuel as I suggested previously to see if your issue is affected by that. You will probably not have to richen it up so much then and save some fuel then.

In terms of compression:

You have to look at your effective compression ratio which is something like that:

(Atmospheric pressure + turbo gauge pressure) x static compression ratio

So, to simplify let's assume we have 1 bar of atmospheric pressure.

Effective CR = (1 bar + 1.1 bar) x 9 = 18.9 bar (at 1.1 bar turbo pressure)

Now, take a low compression engine:

Effective CR = (1 bar + 1.1 bar) x 8.5 = 17.85 bar

And lastly let's find out how much boost you can run on a low compression engine to reach the same effective CR:

( Effective CR / 8.5 -1) = 1.22 bar

Not sure how this translates into reality since it is oversimplifying things, but what it means is that with 1.1 bar on a LPT you should have a similar octane requirement as a HPT with about 1.2 bar.

[Midnight Caller]

Those are some interesting calculations you have there !

It would be interesting to find a relationship between octane number and Effective CR so we can find out how much we can up the boost (without taking into account the ignition) without going into autodetonation caused by compression.

But I guess that's the subject of another topic of general interest, I think I'll open one later, but first I'll document myself a bit.

As for Ethanol, nope, there's no such option here in Romania. There were some discussions about introducing it in 10% proportion, but is was that and nothing more.