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Discussion Starter · #1 ·
I noticed in another thread that some of you wanted to know the definitive AFR/Lambda target on a stock file so I thought I'd post this FYI.

Factory files only enrich based on the actual level of boost (load) with an additive based on knock detection.

In essence a factory R file wants 0.9 lambda across the board which looks mega lean taking into account it hits between 0.95 and 1.1 bar ish.

The interesting bit is that the factory calibrate additional fueling based on knock (ignition retardation) but it couldn't give a flying F about knock until it retards 4 degrees.

At 4 degrees retardation fuelling increases to 0.85 lambda
At 6 degrees, about 0.84
At 10 degrees 0.8 until 5000rpm where it enriches to 0.77 lambda.

You can see from this that the fuelling strategy only targets common power based fueling lambda (0.85/0.84) once knock is at 6 degrees; and it's not bothered at all until 4 degrees.

The Volvo knock control is 馃憣 (it's very sensitive indeed).

MTE used to exploit this and ride the knock control. This technique is now well out of favour and tuners these days tend to try and remove all trace of knock. Don't get me wrong, this isn't in itself bad but I've yet to see properly considered fueling based on the method Volvo originally used and most tend to just use gas pedal angle based request (LAMFA) which was totally switched off originally (because it's a bit crap as a primary strategy IMO).

Anyway. It interested me so it might you guys. 馃憣馃槑
 

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So don鈥檛 get any tunes for the R? That鈥檚 the tl;dr version correct?


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Discussion Starter · #6 · (Edited)
Not what I'm saying at all. Do what you want... but I can attest to this community's previous favourite (and raved over) tuner before Gustav turning off the excellent factory system in favour of pedal based (read archaic) primary fueling. Probably because it was all based on 'Wide Open Throttle' logs.

My point is that I've set my own car up so that I can have it target a certain lambda value; it will enrich from that or lean out again to carefully calculated limits all on its own - keeping knock in check which means I can run a ton more ignition than I've seen other tuners use.

I've done it the original "Volvo" way and it's awesome. I'd go far enough to say my (Volvo) way is the best way in fact. Needs some basic maths skills to work it all out (it's not hard) but everyone else does it backwards. Meh.

Go figure...
 

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I don't know sh!t about tuning but found all this really interesting. Would you tune other people's cars?
 

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Discussion Starter · #8 · (Edited)
I've never done so commercially but have tuned a few previously sure. Maybe 20 over the last 2 years or so? Just done an E85 monster which was cool. Some I've done just for fun lol. It's reasonably straightforward once you have the knowledge and tools to do it remotely etc.

Helped a guy this week who'd had a bad experience with a tuner and wasn't happy with his tune. Poor guy must have spent 10k on the build and tune. I felt sorry for him so did his for free. What goes around comes around etc...
 

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I noticed in another thread that some of you wanted to know the definitive AFR/Lambda target on a stock file so I thought I'd post this FYI.

Factory files only enrich based on the actual level of boost (load) with an additive based on knock detection.

In essence a factory R file wants 0.9 lambda across the board which looks mega lean taking into account it hits between 0.95 and 1.1 bar ish.

The interesting bit is that the factory calibrate additional fueling based on knock (ignition retardation) but it couldn't give a flying F about knock until it retards 4 degrees.

At 4 degrees retardation fuelling increases to 0.85 lambda
At 6 degrees, about 0.84
At 10 degrees 0.8 until 5000rpm where it enriches to 0.77 lambda.

You can see from this that the fuelling strategy only targets common power based fueling lambda (0.85/0.84) once knock is at 6 degrees; and it's not bothered at all until 4 degrees.

The Volvo knock control is 馃憣 (it's very sensitive indeed).

MTE used to exploit this and ride the knock control. This technique is now well out of favour and tuners these days tend to try and remove all trace of knock. Don't get me wrong, this isn't in itself bad but I've yet to see properly considered fueling based on the method Volvo originally used and most tend to just use gas pedal angle based request (LAMFA) which was totally switched off originally (because it's a bit crap as a primary strategy IMO).

Anyway. It interested me so it might you guys. 馃憣馃槑
Not what I'm saying at all. Do what you want... but I can attest to this community's previous favourite (and raved over) tuner before Gustav turning off the excellent factory system in favour of pedal based (read archaic) primary fueling. Probably because it was all based on 'Wide Open Throttle' logs.

My point is that I've set my own car up so that I can have it target a certain lambda value; it will enrich from that or lean out again to carefully calculated limits all on its own - keeping knock in check which means I can run a ton more ignition than I've seen other tuners use.

I've done it the original "Volvo" way and it's awesome. I'd go far enough to say my (Volvo) way is the best way in fact. Needs some basic maths skills to work it all out (it's not hard) but everyone else does it backwards. Meh.

Go figure...
Since you were making quite a few statements, I鈥檇 like to address a few.

1. First and foremost, any OEM, including Volvo, will always prioritize emissions and fuel consumption. This is the reason why the factory tunes run at Lambda 1 for majority of times. Just because they do that, doesn鈥檛 mean it is best strategy for power and safe power.

2. The point of original post was to inform members of the community about how fueling works in an R model (I should specify that this is not the same for all model years...). Yet you clearly have misunderstood the strategy yourself and are publishing info that is incorrect. The map you are talking about has nothing to do with knock or degrees of knock. If you actually read the instructions sheet for ECU or looked at the code, it would be obvious. Volvo has never used 鈥渒nock based鈥 fueling control in ME7.
The 4, 6 or 10 degrees of knock that you say deteremine the amount of enrichment. The values actually represent delta ignition angle efficiency. Nothing to do with degrees in crank angle as such. Ignition angle efficiency can be better or worse by many things (yes knock included). But the whole function has nothing to do with how many degrees ECU retards timing directly.

3. The map for primary fuel, which you so dearly despise of, is not used on stock tunes because of aforementioned reason - emissions and fuel economy. MTE did use it, Volvo factory tunes for Challenge series used it (can you belive OEM engineers opted for an archaic strategy?). Also other tuners, who understand the concept, use it.
I would also like to point out another bit of misinformation you stated about that map being dependent of gas pedal angle. That is not true as it is based on torque request which can be linear to pedal angle or very far from it (R pedal maps).

4. What I turn on or off in my tunes is based on the current project and whatever goal is to be achieved.
The fueling enrichment doesn鈥檛 really help with knock. Knock goes away fastest if you retard ignition angle. Retarding ignition angle causes hotter exhaust gas temperature. The enrichment maps and strategy you speak of throughout this thread is solely designed to reduce exhaust gas temperature. Whatever the cause for that raise in temperature be.

5. You say you run a ton more ignition timing than any other tuner. Did you also know that increasing ignition timing for more power and then allowing the ECU to dump fuel to cope with increased exhaust temperature because knock threshold is achieved kinda negates the point. The richer you go in air-fuel ratio, the slower the burn speed. The high timing value may look nice in datalog, but is it really best have engine deliberately knock and end result is not more power? Have you ever listened to an engine with det cans at wide open throttle that is under constant 6 degrees of knock retard? It may be my quirk, but to me it sounds horrible.

6. I will not claim one method is the best or worse when it comes to tuning. This thread is not about that. I鈥檒l leave it up to the reader to decide.

Backwards arhaic tuner out *mic drops
 

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There was a dash light on 200s and early 700s that has a tiny little speedo cable driving a counter box to click the light switch on to remind you to change the sensor. Then they stretched the interval to much more than 30 K miles and dropped a fixed reminder system.
 

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Discussion Starter · #12 · (Edited)
It's worth mentioning that in VAG ME7 the best tuners set pedal based request (LAMFA) lambda to target 0.88 or 0.85 and then use the primary fueling based either on load or knock (or both). Pretty much fact.

Using the above method will allow fueling to almost instantly target best power using pedal request, whilst load request can then 'take over' fuelling when boost/load increases etc. How does that not make sense?

Sure, pedal request is faster but has the risk of being too rich or too lean under a number of other conditions.

As Volvo choose not to implement knock based enrichment as an additional fuelling strategy like it's VAG form, it leaves only LAMFA (pedal) or the much more comprehensive BTS module as options.

BTS is the better and more accurate option than LAMFA to fuel a boosted car. Fact.

BTS is switched off in low tune state cars to target lambda 1.0 for emissions and MPG sure, but is switched on in the R as I've said... and???

Tuning remotely has its caveats. No Dyno. If you butt Dyno your car and are happy with it then cool. Otherwise you are only measuring Wide Open Throttle Pulls via datalogger or an actual Dyno and NOT daily part throttle performance.

Say what you want G, but LAMFA as the primary and only enrichment 95% of the time isn't a good idea. You may as well just fit a carburettor.

You're correct obvs over defining "ignition angle efficiency" but I've logged it and setting up KFLDBTS properly will result in fuelling floating below the KFLBTS setpoint exactly where I want it to be and in PERFECT correlation to knock events. Accident? NO. Reduced knock events YES. More advance? YES. Why? Because delta ignition angle efficiency is mostly based on knock in BTS anyway:


Quote:
"Btw, those that use KFLAMKRL, what do you guys do with KFDLBTS? These basically duplicate each other." - PRJ (Dimitri). Nefmoto 2012. You suggesting that know better than him?

The result of doing it my way is DYNAMIC (not static) WOT fuel enrichment which has resulted in a better drive in all circumstances.

As is, all I've seen is Volvo tuners past and (if I read correctly) present?? increasing the BTS threshold and messing with the table in an arbitrary way that looks nice in winols but the moment you add "ignition angle degredation" enrichment via KFLDBTS, fueling loads up to like 0.6 lambda FFS.. so basically, the table is useless. Plus, switching off ATR (exhaust gas temperature control) at this point means you need to tune out ALL knock to ensure that KFLBTS then works correctly. We discussed this years ago.

In relation to MTE tunes, LAMFA and KFLBTS work in tandem in the best files Marco made; they reflect one another and work together which totally illustrates my point. Using LAMFA in isolation until exhaust temps exceed what 850-900 deg plus? Good idea?? Nope.

Now if anyone tells me that (for example) APR tunes their 9 second TTRS monsters using nothing other than pedal request... I'll stand corrected, but I'd (respectfully) suggest you pick that mic back up 馃槈
 
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