K & N Air filter

wammers said:

... I will say again, for any given RPM/power demand or manifold pressure air is constant the only thing that changes is the amount of fuel injected

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I should quit trying to convince you things cos even if i'm sure you know perfectly how the engine works you have serious lacks in how the electronic management works though, but i'm always up to a juicy debate and at least those who are watching this will throw theyr's own conclusions, i cropped a part from one data log i have which was sent to me by somebody, it's about a Eu3 de-EGR'd Td5 with factory fuel map, the coloums are as folows:
A = RPM, B = road speed, C = idle speed error, D = TPS track1, E = TPS track2, F = TPS track3, G = TPS supply, H = Batt. V, I = MAF, J = AAP, K = MAP, L = IAT, M = ECT, N = FT, O = EGR inlet, P = EGR modulator, Q = Wastegate modulator
Check out from positions 279-280 and you'll see same driver demand, same RPM, virtually same MAP and MAF growing with 15 units(which according to your theory should never happen), then if you watch further down you'll see IAT growing fast together with the MAF and almost constant MAP, even dropping a bit due to increased wastegate modulation, which means the ECU adjusted fuelling based on MAF reading exactly because on Eu3 engines the IQ is calculated based on MAF/RPM readings as explained in that link i posted...if you know how to interpret a log like that this becomes obvious .... also you can see that the EGR is managed like it's there even if it's not cos the ILT modulator was left in place so it has nothing to do with the air flow in this case.... i think now it's time to deffinitely rest my case and the posterity will decide

Ok now put one up with an active EGR were the road speed is constant, manifold pressure is constant, the RPM is constant, and the flow through the MAF is up to 50% less than it was before EGR came in. Then tell me fuelling is subject to airflow through the MAF sensor.

I dont have one with active EGR cos they are not many left but i've never said that MAF it's there alone for fuelling and i admit without any doubt that it's there mainly for EGR controll, aamof the EGR will not exceed 40% whatsoever...the ECU has the ability to swap the IQ calculation between MAF/RPM and MAP/IAT if the MAF reading becomes unplausible or when EGR is activated, as the ECU does it all so when it activates the EGR it swaps the calculation to MAP/IAT especially cos the IAT will have a sudden rise due to the exhaust gasses then the fuelling must be reduced, read this http://www.discotd5.com/ecu-reverse-engineering/airmass , the guy(who IMO is the best when it comes to Td5 engine management) neglected the EGR cos for that demonstration it's irrelevant, also the airmass MAF/RPM calculation is more accutrate that's why de-EGR'd Eu3 engines will run the best with a well working MAF while .... and that's a well known fact from many posts in many forums where members with de-EGR'd engines all noticed an improvement in driveability and consumption after they changed a failed MAF ...that's why it's named ADDAPTIVE STRATEGY

sierrafery said:

I dont have one with active EGR cos they are not many left but i've never said that MAF it's there alone for fuelling and i admit without any doubt that it's there mainly for EGR controll, aamof the EGR will not exceed 40% whatsoever...the ECU has the ability to swap the IQ calculation between MAF/RPM and MAP/IAT if the MAF reading becomes unplausible or when EGR is activated, as the ECU does it all so when it activates the EGR it swaps the calculation to MAP/IAT especially cos the IAT will have a sudden rise due to the exhaust gasses then the fuelling must be reduced, read this http://www.discotd5.com/ecu-reverse-engineering/airmass , the guy(who IMO is the best when it comes to Td5 engine management) neglected the EGR cos for that demonstration it's irrelevant, also the airmass MAF/RPM calculation is more accutrate that's why de-EGR'd Eu3 engines will run the best with a well working MAF while .... and that's a well known fact from many posts in many forums where members with de-EGR'd engines all noticed an improvement in driveability and consumption after they changed a failed MAF

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That is because whilst the MAF plays no part in fuelling lack of info from it can cause the ECU to become confused. Even more so in EU 3 and later applications. A P38 with EU 2 will run quite happily with the MAF disconnected although you will get an airflow fault on Nanocom.

I know nothing about P38 other than some not engine related electronics, the Eu3 Td5 ECU is "smarter" than to get ''confused'', as long as it doesnt store an air flow fault code and the MAF readings are within pre-mapped limits it uses the MAF/RPM for airmass calculation outside of that the MAP/IAT, as i said it's addaptive strategy not confusion, it's electronic not human... it was built to calculate the airmass as explained in that link, better take some time and analize that demonstration, though if you think its some comics i'll never speak with you about this again

sierrafery said:

I know nothing about P38 other than some not engine related electronics, the Eu3 Td5 ECU is "smarter" than to get ''confused'', as long as it doesnt store an air flow fault code and the MAF readings are within pre-mapped limits it uses the MAF/RPM for airmass calculation outside of that the MAP/IAT, as i said it's addaptive strategy not confusion, it's electronic not human... it was built to calculate the airmass as explained in that link, better take some time and analize that demonstration, though if you think its some comics i'll never speak with you about this again

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It may do all those things, but airflow through the MAF does not dictate how much fuel is injected. That is down to the throttle power request from the drivers right foot.

wammers said:

... airflow through the MAF does not dictate how much fuel is injected. That is down to the throttle power request from the drivers right foot.

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Nobody says it dictates how much is injected, it's just part of a complex ecuation for fuelling calculations too(beside EGR).... what's your scenario when cruise control is set so the throttle is untouched and the vehicle starts climbing a hill which means at that very moment the vehicle speed, the rpm and air flow will drop and the ECU must compensate for the speed loss, what data will it use then? cos the right foot is resting

sierrafery said:

Nobody says it dictates how much is injected, it's just part of a complex ecuation for fuelling calculations too(beside EGR).... what's your scenario when cruise control is set so the throttle is untouched and the vehicle starts climbing a hill which means at that very moment the vehicle speed, the rpm and air flow will drop and the ECU must compensate for the speed loss, what data will it use then? cos the right foot is resting

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More fuel will be added increasing engine power until the road speed set in the ECU is reached. Nothing to do with airflow through the MAF. IAT and fuel temp do contribute to fine fuel trimming but the airflow does not.

IMO it has to know how more much fuel by managing the IQ... that "more" has to be calculated based on something injection related not just on SLABS input cos then it would take ages to get to the target speed or blow black smoke especially if it's a steep hill

sierrafery said:

IMO it has to know how more much fuel by managing the IQ... that "more" has to be calculated based on something injection related not just on SLABS input cos then it would take ages to get to the target speed or blow black smoke especially if it's a steep hill

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MAP sensor readings will determine how much fuel can be injected without smoke, as i keep saying, nothing to do with airflow through the MAF sensor. Which is used to measure exhaust gas ingestion for EGR purposes.

OK, it seems that you didnt read those links, or you did but you didnt understand, or you did, you understood but you consider them comics .... i think it's useless to continue this debate, i'll let the jury to reach the verdict .... i'm looking forward to a subject where we will fully agree

sierrafery said:

OK, it seems that you didnt read those links, or you did but you didnt understand, or you did, you understood but you consider them comics .... i think it's useless to continue this debate, i'll let the jury to reach the verdict .... i'm looking forward to a subject where we will fully agree

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A diesel engine, any diesel engine, is a very simple device. Fuel is injected and it runs. The more fuel that is injected the faster it runs. There is always more air in the cylinder than is needed for combustion. Diesel engines are NOT throttled by airflow but by fuel. They do not run at a constant stoichiometric mixture ratio. Petrol engines do, diesel engines don't. Fuel is injected subject to power demand within limits set either by mechanical means or electronic mapping. Neither of which need a MAF sensor. MAF sensors were introduced to diesel engines at EU level 2 emission standard. Were a feedback of the amount of ingested exhaust gas was required so that the EGR could be modulated to variably control it. EU 3 went a step further with a much finer balance of exhaust gas to combustible air required. Without EGR a diesel engine would not require a MAF sensor at all. It serves no purpose other than to give feedback for EGR.

wammers said:

A K&N filter may, just may improve airflow and give a slight boost to a normally aspirated engine. But will do nothing whatsoever for a turbo engine.

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Yes, and common sense would suggest to me that improved airflow might mean reduced filtration.

sierrafery said:

OK, it seems that you didnt read those links, or you did but you didnt understand, or you did, you understood but you consider them comics .... i think it's useless to continue this debate, i'll let the jury to reach the verdict .... i'm looking forward to a subject where we will fully agree

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If you think about it, and talk sense, instead of buying the marketing bull, we might agree with you!

Turboman said:

Yes, and common sense would suggest to me that improved airflow might mean reduced filtration.

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No never, how do you come to that conclusion?

wammers said:

No never, how do you come to that conclusion?

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Just a wild stab in the dark, as usual!

And I will have another one. I would guess that sierraferry has not taken into account that while improved airflow will be an improvement on a vehicle such as an F1 car, or high powered motorbike, it will make no difference on a low tuned vehicle with precisely metered availability of fuel. Like a diesel landrover. Which is actually designed to be used in a variety of environments, including deserts, etc.

But of course, it is another well known innernet fact that hobbyists and garage mechanics know much more than the qualified engineers who design vehicle air intakes!

I have one because it makes the turbo sound louder

Turboman said:

Yes, and common sense would suggest to me that improved airflow might mean reduced filtration.

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But it doesn't, you don't have K &N filter then? They still get as black as the paper ones but then u have to fluff about with the clean, it takes me 5mins to replace a paper air filter.

I don't know about today's F1 cars a Moto GP bikes but in my days of paddock tours they didn't have air filters fitted.

Turboman said:

Just a wild stab in the dark, as usual!

And I will have another one. I would guess that sierraferry has not taken into account that while improved airflow will be an improvement on a vehicle such as an F1 car, or high powered motorbike, it will make no difference on a low tuned vehicle with precisely metered availability of fuel. Like a diesel landrover. Which is actually designed to be used in a variety of environments, including deserts, etc.

But of course, it is another well known innernet fact that hobbyists and garage mechanics know much more than the qualified engineers who design vehicle air intakes!

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It's the EU emissions regs that have caused all this crap. Every Disco TD5 engine ECU available is to EU 4. Which makes them far more complicated than an ECU would need to be just to run the engine. If your diesel engine isn't sucking air in you don't need a bloody MAF sensor to tell you that it would be pretty obvious and somewhat terminal.

discool said:

But it doesn't, you don't have K &N filter then? They still get as black as the paper ones but then u have to fluff about with the clean, it takes me 5mins to replace a paper air filter.

I don't know about today's F1 cars a Moto GP bikes but in my days of paddock tours they didn't have air filters fitted.

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It gets black with what it catches some stuff it doesn't catch. A paper filter is far more efficient at catching debris than any K&N will ever be. Some may wonder how you can have a net full of Cod without a single Herring.