Experience please !!!
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Registered User
Joined: Aug 2009
Posts: 1,745
From: KUWAIT
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Experience please !!!
as we all know .. that our cars Affected by the fuel and the weather but the basic thing is the tune!
when we search and look to the values in the durametric program
wee look mostly :
1- spark ( timing )
2- lambada ( air/fuel )
3- air Temperature.
i know that fuel Quality controls the timing .. so when we run high octane fuel the timing will be high
and if we run less octane timing will go low and will pulled by ECU !!!!
i saw alot of data logs for alot of members here i saw many run 17 of spark, some run 18 !!!
But I see that in the U.S cars they can run 20 or 21 of spark !!!
i know running more timing Cause damege
to the engine !!
what i need to know please :
Q1) whats the perfect timing and air fuel we could see to get all the power from our cars ??
Q2) can the tuner control the timing ??
Q3) if someone running meth whats Maximum timing he should see in durametric ?
Q4) as i said i saw data logs for many members i noticed that timing and air/fuel were jumpy
and not steady Through the logs !!!! is that normal ??
Q5) running more timing means more power >> is that correct ??
i hope this kind of informations will be usefull for all of us to
know better and better about our cars !!!
please any informations will be usefull and Grateful ...
Yousef
when we search and look to the values in the durametric program
wee look mostly :
1- spark ( timing )
2- lambada ( air/fuel )
3- air Temperature.
i know that fuel Quality controls the timing .. so when we run high octane fuel the timing will be high
and if we run less octane timing will go low and will pulled by ECU !!!!
i saw alot of data logs for alot of members here i saw many run 17 of spark, some run 18 !!!
But I see that in the U.S cars they can run 20 or 21 of spark !!!
i know running more timing Cause damege
to the engine !!
what i need to know please :
Q1) whats the perfect timing and air fuel we could see to get all the power from our cars ??
Q2) can the tuner control the timing ??
Q3) if someone running meth whats Maximum timing he should see in durametric ?
Q4) as i said i saw data logs for many members i noticed that timing and air/fuel were jumpy
and not steady Through the logs !!!! is that normal ??
Q5) running more timing means more power >> is that correct ??
i hope this kind of informations will be usefull for all of us to
know better and better about our cars !!!
please any informations will be usefull and Grateful ...
Yousef
Registered User
Joined: Feb 2010
Posts: 476
From: Kuwait
Rep Power: 73
Great post ysf. Ur Q's r technical-mechanical. Therefor, real gear heads should show up and through thoughts/ share idea's.. Wish u can find the answers ur looking for 
..
Common gear heads. Lets see what u got
..Common gear heads. Lets see what u got
Registered User
Joined: Jun 2005
Posts: 3,108
From: denver/Saudi
Rep Power: 165
as we all know .. that our cars Affected by the fuel and the weather but the basic thing is the tune!
when we search and look to the values in the durametric program
wee look mostly :
1- spark ( timing )
I don't understand the timing very well but here is what I can say:
If the timing was adjusted by the factory to be 20 degree ( Ideally, the time at which the mixture should be fully burnt)
if timing adjusted to a number lower then 20 the timing considered retarded
if timing adjusted to be more than 20 degrees ( advanced )
too advance >>> the rapidly expanding air-fuel mixture can actually push against the piston still moving up, causing pre-ignition and possible engine damage.
too retarded >>>> maximum cylinder pressure will occur after the piston is already traveling too far down the cylinder. This results in lost power, high emissions, and unburned fuel.
If the air-fuel mixture is ignited at the correct time, maximum pressure in the cylinder will occur sometime after the piston reaches to push down with the greatest force
also the timing can be effected by the engine speed RPM.
2- lambada ( air/fuel )
Lambda is an alternative way to define the AFR ( air fuel ratio ) which in other words mean how much air we need to completely burn all of the fuel. The ratio known as Stoichiometry mixture which for balanced chemical reaction certain amount of reactant result in specific products.
For gasoline fuel, the stoichiometric air/fuel mixture is approximately 14.7. i,e 14.7 of air for each 1 gasoline
to make things simple:
the ratio of 14.7:1 is referred to us as one lambda 1.0 anything less than one means RICH and anything more than one means LEAN.
in naturally aspirated engine most power achieved AFRs ranging from 12.5 - 13.3:1 or λ of 0.850 - 0.901.
3- air Temperature.
cooler air means higher air density which result in more Oxygen inter the engine, and with more Oxygen we can burn or have better fuel burning which produce more power
i know that fuel Quality controls the timing .. so when we run high octane fuel the timing will be high
and if we run less octane timing will go low and will pulled by ECU !!!!
i saw alot of data logs for alot of members here i saw many run 17 of spark, some run 18 !!!
But I see that in the U.S cars they can run 20 or 21 of spark !!!
i know running more timing Cause damege
to the engine !!
what i need to know please :
Q1) whats the perfect timing and air fuel we could see to get all the power from our cars ??
it's the one that produce the maximum pressure in the cylinder after the piston reaches to push down with the greatest force but I don't know what it is for our cars
Q2) can the tuner control the timing ??
yes
Q3) if someone running meth whats Maximum timing he should see in durametric ?
Q4) as i said i saw data logs for many members i noticed that timing and air/fuel were jumpy
and not steady Through the logs !!!! is that normal ??
Q5) running more timing means more power >> is that correct ??
i hope this kind of informations will be usefull for all of us to
know better and better about our cars !!!
please any informations will be usefull and Grateful ...
Yousef
when we search and look to the values in the durametric program
wee look mostly :
1- spark ( timing )
I don't understand the timing very well but here is what I can say:
Ignition angle – this is the degree of advance which the engine is running at, basically higher advance number the better and a steady number shows a more balanced engine tune.
if timing adjusted to a number lower then 20 the timing considered retarded
if timing adjusted to be more than 20 degrees ( advanced )
too advance >>> the rapidly expanding air-fuel mixture can actually push against the piston still moving up, causing pre-ignition and possible engine damage.
too retarded >>>> maximum cylinder pressure will occur after the piston is already traveling too far down the cylinder. This results in lost power, high emissions, and unburned fuel.
If the air-fuel mixture is ignited at the correct time, maximum pressure in the cylinder will occur sometime after the piston reaches to push down with the greatest force
also the timing can be effected by the engine speed RPM.
2- lambada ( air/fuel )
Lambda is an alternative way to define the AFR ( air fuel ratio ) which in other words mean how much air we need to completely burn all of the fuel. The ratio known as Stoichiometry mixture which for balanced chemical reaction certain amount of reactant result in specific products.
For gasoline fuel, the stoichiometric air/fuel mixture is approximately 14.7. i,e 14.7 of air for each 1 gasoline
to make things simple:
the ratio of 14.7:1 is referred to us as one lambda 1.0 anything less than one means RICH and anything more than one means LEAN.
in naturally aspirated engine most power achieved AFRs ranging from 12.5 - 13.3:1 or λ of 0.850 - 0.901.
3- air Temperature.
cooler air means higher air density which result in more Oxygen inter the engine, and with more Oxygen we can burn or have better fuel burning which produce more power
i know that fuel Quality controls the timing .. so when we run high octane fuel the timing will be high
and if we run less octane timing will go low and will pulled by ECU !!!!
i saw alot of data logs for alot of members here i saw many run 17 of spark, some run 18 !!!
But I see that in the U.S cars they can run 20 or 21 of spark !!!
i know running more timing Cause damege
to the engine !!
what i need to know please :
Q1) whats the perfect timing and air fuel we could see to get all the power from our cars ??
it's the one that produce the maximum pressure in the cylinder after the piston reaches to push down with the greatest force but I don't know what it is for our cars
Q2) can the tuner control the timing ??
yes
Q3) if someone running meth whats Maximum timing he should see in durametric ?
Q4) as i said i saw data logs for many members i noticed that timing and air/fuel were jumpy
and not steady Through the logs !!!! is that normal ??
Q5) running more timing means more power >> is that correct ??
i hope this kind of informations will be usefull for all of us to
know better and better about our cars !!!
please any informations will be usefull and Grateful ...
Yousef
a lot of info was gathered from different online sources. I would assign some HW's for you and google all the terms you see with each member data log and you will be confused by how much info there are.
I could be wrong in some info above but that my level of knowledge and others comments are always welcomed
Abdullah
Last edited by cayenne_ksa; Oct 3, 2010 at 01:03 AM.
Registered User
Joined: Jan 2010
Posts: 239
From: kuwait
Rep Power: 29
This is a friend of P2P typing. Im the guy who wired up his HKS EVC.
From what I know these bosch ECUs (MOTRONIC units if im not mistaken) are VERY good at learning and very aggresive when it comes to safety precautions. in otherwords the ecu is smart.
so spark timing. since spark timing varies with IAT and Lambda and Boost pressure and load and a bunch of other things there is no SET number to look for.
except that as rpm increases spark timing goes UP (advanced) and with everything else with lambda boost and iat and load going up timing goes down (retarded).
BUT as long as timing goes up or down or stays the same smoothly you know everything is working properly and nothing is confusing or scaring your ecu into doing things that will make you lose more power than you should.
ON THE OTHER HAND if the spark timing goes up and down and spikes and looks like it was drawn by a hyperactive monkey then your ecu is pulling timing because of a knock event. knock events i dont need to tell you are bad. they are usually cause by overboosting with low quality fuel mixed with high iat. or excessivly high cylinder temperature, or overly lean fuel mixture. and many more things but if it constantly happens above a certain variable parameter for example IAT then its a matter of tuning trims, (the ecu doesnt have enough retard tuned in it for high IAT, so the knock sensor goes off and this triggers the safety program in the ecu and this retards timing until the knock goes, then it goes back to normal which brings back the knock. this causes the spikes and jagged lines on your datalogging timing graph).
second lambda. ideally for boosted cars lambda should be about 0.8 some cars go lower for safety, and some go a little higher for added power but nearing the 0.9 or even 0.85 mark is pushing it. also the higher the boost the lower the lamda you should aim for. because the higher the lambda (more lean) the higher the temperatures inside the cylinder are. and higher cylinder temperatures the more likely your engine is to knock.
IAT. colder air = more dense air=more oxygen= you need more fuel. this all adds up to more power. but whereas hot air can increase zylinder temperatures and cause knock. if the air is too cold and your injectors are too small to feed the extra fuel need your car will run lean and again cylinder temperature goes up and you get knocking.
Yes running more timing means more power. fuel takes time to burn and you get maximum power if you get maximum cylinder pressure at 15 degrees after top dead centre. anything after that = less power and anything before that =less power (but still no knocking) knocking is when you reach maximum (or very high) cylinder pressure before 0 degrees (top dead centre).
also i recommend logging injector pulse time to find your injector duty cycle.
you have to use a formula because the porsche ecu doesnt give duty cycle only intector time in milliseconds. the formula to convert is...
(injector pulse width in milliseconds. x rpm) / 1200. this gives duty cycle in percent
tuners can control timing sets and can modify the some of the safety retard parameters (not recommended)
meth cools the air and runs richens mixture. and unless the ecu is TOLD to advance timing the timing wont go up much because it reads off only the IAT and the lamda. it can in some cases confuse the ecu into increasing the timing too much and knocking because the lamda will read too rich which will set off aggressive timing retard and you will get timing spikes.
I know i typed too much. but i hope it helps you with interpreting your datalogs better. and if you need any help you can just get a hold of p2p as i dont have a 6speed account.
edit. your target injector duty cycle should be around 75-85% because you want a little bit of safety margin for unforseen engine requirements. also anything above 90% or even 95% if fuel pressure is higher than stock your injectors go static (constantly on because they dont have time to close between injection events) here you lose control of fuelling and this can cause problems with the ecu controlling the fuelling to reach target lambda
From what I know these bosch ECUs (MOTRONIC units if im not mistaken) are VERY good at learning and very aggresive when it comes to safety precautions. in otherwords the ecu is smart.
so spark timing. since spark timing varies with IAT and Lambda and Boost pressure and load and a bunch of other things there is no SET number to look for.
except that as rpm increases spark timing goes UP (advanced) and with everything else with lambda boost and iat and load going up timing goes down (retarded).
BUT as long as timing goes up or down or stays the same smoothly you know everything is working properly and nothing is confusing or scaring your ecu into doing things that will make you lose more power than you should.
ON THE OTHER HAND if the spark timing goes up and down and spikes and looks like it was drawn by a hyperactive monkey then your ecu is pulling timing because of a knock event. knock events i dont need to tell you are bad. they are usually cause by overboosting with low quality fuel mixed with high iat. or excessivly high cylinder temperature, or overly lean fuel mixture. and many more things but if it constantly happens above a certain variable parameter for example IAT then its a matter of tuning trims, (the ecu doesnt have enough retard tuned in it for high IAT, so the knock sensor goes off and this triggers the safety program in the ecu and this retards timing until the knock goes, then it goes back to normal which brings back the knock. this causes the spikes and jagged lines on your datalogging timing graph).
second lambda. ideally for boosted cars lambda should be about 0.8 some cars go lower for safety, and some go a little higher for added power but nearing the 0.9 or even 0.85 mark is pushing it. also the higher the boost the lower the lamda you should aim for. because the higher the lambda (more lean) the higher the temperatures inside the cylinder are. and higher cylinder temperatures the more likely your engine is to knock.
IAT. colder air = more dense air=more oxygen= you need more fuel. this all adds up to more power. but whereas hot air can increase zylinder temperatures and cause knock. if the air is too cold and your injectors are too small to feed the extra fuel need your car will run lean and again cylinder temperature goes up and you get knocking.
Yes running more timing means more power. fuel takes time to burn and you get maximum power if you get maximum cylinder pressure at 15 degrees after top dead centre. anything after that = less power and anything before that =less power (but still no knocking) knocking is when you reach maximum (or very high) cylinder pressure before 0 degrees (top dead centre).
also i recommend logging injector pulse time to find your injector duty cycle.
you have to use a formula because the porsche ecu doesnt give duty cycle only intector time in milliseconds. the formula to convert is...
(injector pulse width in milliseconds. x rpm) / 1200. this gives duty cycle in percent
tuners can control timing sets and can modify the some of the safety retard parameters (not recommended)
meth cools the air and runs richens mixture. and unless the ecu is TOLD to advance timing the timing wont go up much because it reads off only the IAT and the lamda. it can in some cases confuse the ecu into increasing the timing too much and knocking because the lamda will read too rich which will set off aggressive timing retard and you will get timing spikes.
I know i typed too much. but i hope it helps you with interpreting your datalogs better. and if you need any help you can just get a hold of p2p as i dont have a 6speed account.
edit. your target injector duty cycle should be around 75-85% because you want a little bit of safety margin for unforseen engine requirements. also anything above 90% or even 95% if fuel pressure is higher than stock your injectors go static (constantly on because they dont have time to close between injection events) here you lose control of fuelling and this can cause problems with the ecu controlling the fuelling to reach target lambda
Last edited by P2P; Oct 18, 2010 at 10:44 PM.
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