Powerforum

Hvordan stiller i tænding ved dellast og fuldlast ?

Giv den tænding til du kan høre at den begynder at klirre, og så et par grader tilbage...

Er der så nogen der kan anbefale et firma som er gode til at indkøre dette produkt??

Jeg vil gerne have den køre så tæt på 100% som muligt uden at aflevere bilen flere gange..

Jeg skal kun bruge det til std. bil til std. kørsel 75%af tiden. De sidste 15% er ude på vejene og måske i holleby bare 1-2 ture..

Det er ikke en racer bil, men en flyder som cruise rundt i og have det sjovt nogle gange...

Mads B (dk) skrev:Hvordan stiller i tænding ved dellast og fuldlast ?

Det bliver tit holdt hemmeligt hvordan man justere det.
MEGET hemmeligt i HKS kredse, da mappen er låst, dog kan man snyde den.

Det er nok ikke det store problem i MS kredse, men delte meninger om hvad der er bedst.
På turbo biler, kan nogen godt lide ret konservativ tænding, ved dellast/cruise for og holde udstødningshus varm.

Men det har også en del og sige, hvad bilen skal bruges til, og om det er en standard turbo motor, eller voltunet...

Fik min ms justeret hos rene turbomotor på vejen.
Den trækker fint og ingen brændte stempler endnu
4agte motor 300 hk

Alex_Reedtz skrev:Giv den tænding til du kan høre at den begynder at klirre, og så et par grader tilbage...

Den metode kender jeg godt, men ved dellast kan/kunne man nøjes med meget mindre tænding end bankegrænse -2grader hvis jeg har forstået dette ret.

Hente fra
http://195.159.109.134/vemsuk/forum/ind ... ,97.0.html

Knock (detonation) and MBT
For most engines setup with a sensible compression ratio, and certainly for forced induction engines, we end up dividing the speed load map into 2 basic areas – MBT limited, and knock limited. But what do these terms actually mean?

MBT
MBT (Minimum advance for Best Torque) is the normal operating mode of the engine. This is the ignition advance setting that you should strive for unless you become detonation limited. If we were to use an in cylinder pressure measuring device (which we won’t because they are really very expensive) we would find that generally MBT equates to the peak cylinder pressure occurring around 12 degrees after TDC, or even more accurately, when the 50% mass fraction burned (i.e. when we are halfway through combustion) occurs at around 8 degrees ATDC. Because the flame speed varies with various factors, the time at which we ignite the charge changes for speeds (earlier with higher speeds) and load (later with higher load) so that the best bit of the burn remains in the right place. If we move the ignition timing either side of this optimum timing the torque drops. It just so happens that the manner in which it does this, when expressed as a percentage of the optimum torque, is pretty repeatable across the speed and load domain, and this leads to the ignition efficiency curve

So, if you were to perform a spark sweep (i.e. change ignition timing in 2deg steps from advanced of optimum to retarded from optimum) with everything else fixed (speed, throttle position, lambda, inlet temperatures etc) this would be the resulting torque as a percentage of the maximum torque seen at that condition. Remember this is fixed load – the air and fuel being used don’t change. The change in torque is purely down to how effectively we burn that air and fuel. The generic curve is produced by running spark sweeps at a large number of speeds, loads etc and then taking the average. In a modern production EMS this curve is then used as part of the torque control system to help control the engine during torque down requests (e.g. auto trans gearshift), idle and so on.

The eagle eyed among you may have noticed that around the 100% efficiency the curve is quite flat – there is very little change in torque for quite a large (maybe 10 degrees) change in ignition advance. This is where the ‘Minimum’ bit comes in. Normal practice is to set the ignition timing on the retarded side at the point where the torque just begins to drop – e.g. the 99.5% point. This is the best for the engine as it produces the most torque for the least peak cylinder pressure.

I've also added an example of EGT increase with retard from MBT. The curve shape is a bit like the inverse of the efficiency map (not a surprise really), so the further from MBT you are the greater the temp increase. Those numbers are NOT generic though so make sure you measure it yourself. Its not a one size fits all curve.

So the ignition timing at which you get the most torque is MBT. This is the ignition timing we are aiming for over most of the map. But at higher loads towards WOT, or for lower RON fuels, higher inlet temps etc we run into knock before we are able to reach the MBT point. This is known as being 'det limited'.

Alex_Reedtz skrev:Giv den tænding til du kan høre at den begynder at klirre, og så et par grader tilbage...

Den metode kender jeg godt, men ved dellast kan/kunne man nøjes med meget mindre tænding end bankegrænse -2grader hvis jeg har forstået dette ret.

Hente fra
http://195.159.109.134/vemsuk/forum/ind ... ,97.0.html

Knock (detonation) and MBT
For most engines setup with a sensible compression ratio, and certainly for forced induction engines, we end up dividing the speed load map into 2 basic areas – MBT limited, and knock limited. But what do these terms actually mean?

MBT
MBT (Minimum advance for Best Torque) is the normal operating mode of the engine. This is the ignition advance setting that you should strive for unless you become detonation limited. If we were to use an in cylinder pressure measuring device (which we won’t because they are really very expensive) we would find that generally MBT equates to the peak cylinder pressure occurring around 12 degrees after TDC, or even more accurately, when the 50% mass fraction burned (i.e. when we are halfway through combustion) occurs at around 8 degrees ATDC. Because the flame speed varies with various factors, the time at which we ignite the charge changes for speeds (earlier with higher speeds) and load (later with higher load) so that the best bit of the burn remains in the right place. If we move the ignition timing either side of this optimum timing the torque drops. It just so happens that the manner in which it does this, when expressed as a percentage of the optimum torque, is pretty repeatable across the speed and load domain, and this leads to the ignition efficiency curve

So, if you were to perform a spark sweep (i.e. change ignition timing in 2deg steps from advanced of optimum to retarded from optimum) with everything else fixed (speed, throttle position, lambda, inlet temperatures etc) this would be the resulting torque as a percentage of the maximum torque seen at that condition. Remember this is fixed load – the air and fuel being used don’t change. The change in torque is purely down to how effectively we burn that air and fuel. The generic curve is produced by running spark sweeps at a large number of speeds, loads etc and then taking the average. In a modern production EMS this curve is then used as part of the torque control system to help control the engine during torque down requests (e.g. auto trans gearshift), idle and so on.

The eagle eyed among you may have noticed that around the 100% efficiency the curve is quite flat – there is very little change in torque for quite a large (maybe 10 degrees) change in ignition advance. This is where the ‘Minimum’ bit comes in. Normal practice is to set the ignition timing on the retarded side at the point where the torque just begins to drop – e.g. the 99.5% point. This is the best for the engine as it produces the most torque for the least peak cylinder pressure.

I've also added an example of EGT increase with retard from MBT. The curve shape is a bit like the inverse of the efficiency map (not a surprise really), so the further from MBT you are the greater the temp increase. Those numbers are NOT generic though so make sure you measure it yourself. Its not a one size fits all curve.

So the ignition timing at which you get the most torque is MBT. This is the ignition timing we are aiming for over most of the map. But at higher loads towards WOT, or for lower RON fuels, higher inlet temps etc we run into knock before we are able to reach the MBT point. This is known as being 'det limited'.

Kaas skrev:Men Rune når du skal til og igang, så kommer du bare op, så viser jeg de grundlæggende ting som vi gjorde med din kammerats E86

Jo, tusind mange tak, men jeg tror jeg får brug for hjælp allerede når jeg har sat ms-boksen ind i bilen, både med ledningsnet og opsætning til trigger, og al programmering

Mads B (dk) skrev:

Alex_Reedtz skrev:Giv den tænding til du kan høre at den begynder at klirre, og så et par grader tilbage...

Den metode kender jeg godt, men ved dellast kan/kunne man nøjes med meget mindre tænding end bankegrænse -2grader hvis jeg har forstået dette ret.

Hente fra
http://195.159.109.134/vemsuk/forum/ind ... ,97.0.html

Knock (detonation) and MBT
For most engines setup with a sensible compression ratio, and certainly for forced induction engines, we end up dividing the speed load map into 2 basic areas – MBT limited, and knock limited. But what do these terms actually mean?

MBT
MBT (Minimum advance for Best Torque) is the normal operating mode of the engine. This is the ignition advance setting that you should strive for unless you become detonation limited. If we were to use an in cylinder pressure measuring device (which we won’t because they are really very expensive) we would find that generally MBT equates to the peak cylinder pressure occurring around 12 degrees after TDC, or even more accurately, when the 50% mass fraction burned (i.e. when we are halfway through combustion) occurs at around 8 degrees ATDC. Because the flame speed varies with various factors, the time at which we ignite the charge changes for speeds (earlier with higher speeds) and load (later with higher load) so that the best bit of the burn remains in the right place. If we move the ignition timing either side of this optimum timing the torque drops. It just so happens that the manner in which it does this, when expressed as a percentage of the optimum torque, is pretty repeatable across the speed and load domain, and this leads to the ignition efficiency curve

So, if you were to perform a spark sweep (i.e. change ignition timing in 2deg steps from advanced of optimum to retarded from optimum) with everything else fixed (speed, throttle position, lambda, inlet temperatures etc) this would be the resulting torque as a percentage of the maximum torque seen at that condition. Remember this is fixed load – the air and fuel being used don’t change. The change in torque is purely down to how effectively we burn that air and fuel. The generic curve is produced by running spark sweeps at a large number of speeds, loads etc and then taking the average. In a modern production EMS this curve is then used as part of the torque control system to help control the engine during torque down requests (e.g. auto trans gearshift), idle and so on.

The eagle eyed among you may have noticed that around the 100% efficiency the curve is quite flat – there is very little change in torque for quite a large (maybe 10 degrees) change in ignition advance. This is where the ‘Minimum’ bit comes in. Normal practice is to set the ignition timing on the retarded side at the point where the torque just begins to drop – e.g. the 99.5% point. This is the best for the engine as it produces the most torque for the least peak cylinder pressure.

I've also added an example of EGT increase with retard from MBT. The curve shape is a bit like the inverse of the efficiency map (not a surprise really), so the further from MBT you are the greater the temp increase. Those numbers are NOT generic though so make sure you measure it yourself. Its not a one size fits all curve.

So the ignition timing at which you get the most torque is MBT. This is the ignition timing we are aiming for over most of the map. But at higher loads towards WOT, or for lower RON fuels, higher inlet temps etc we run into knock before we are able to reach the MBT point. This is known as being 'det limited'.

stil den så motoren kører bedst muligt!
let dellast på en turbomotor er oftest en sugemotor med prop i udstødning og reelt 4-1 i komp.... hvad fortænding den kører bedst med er forskelligt fra motor til motor. MEGET!
MVH søren

JBO skrev:Så kan morten snart blive ansat ved de store bilfabrikker og lave map til motorstyringer

De kan næppe bruge en ældre automekanikker!
Men vælger hellere en bagerjomfru, uden forudindfattede meninger, som de selv kan lære op

Det er ikke sort magi at justere en motorstyring ind
Selvom mange vil påstå det

Det man køber når man vil have et nøglefærdigt system.
Er erfaring og evnen hos tuneren at se i krystalkuglen.

Der findes dem der er meget dyktige!

Og desværre findes der nogen med minimal erfaring, og de har aldrig hørt om en krystalkugle

Og resultater er at køberen må starte forfra.
Dels med at lære at justere en motorstyring, og dels med at undersøge alt og stille spørgsmålstegn ved alt der er lavet, eller ikke lavet!

MVH

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