open intake maf scaling

[porkhang]

so does anyone have a map with a scaling for open filter intake? if possible, one with a buschur intake pipe and filter? but any would work.

i am asking if you would share it with me, please?

i want to see what the difference is between the stock scaling and the open filter scaling. i perhaps might use your scaling too if i have permission. if u can also let me know what units u scaled in also

[C6ect.ect]

Apart from what many claim, I don't really think too many people are familiar yet with the behavior of those tables when tuning respectfully for a particular intake, even though it is the table that needs to be adjusted for it. There are too many variables to consider outside the laboratory, like, climate, the install, baro table, temp table, smoothing.

Most people just smooth the AFR and keep the MAF stock

[Freon]

The whole point of a hot wire MAF is that it does not vary (much?) with humidity, temperature, and atmospheric pressure. By far, the MAF should react to mass air flow, not other factors. This is why almost all modern cars use a MAF sensor, and even then a hot wire MAF sensor.

I'm not familiar specifically with tuning an intake on an EVO, but the same principles should hold compared to a Subaru. There should be a table that defines the transfer function of the sensor, and changes in the intake can affect how the table should be set up.

I'm not sure what this concentration on the term "open filter" means. I'm not sure there is anything particularly special about an intake that has the air filter not enclosed by a box if that is what you're talking about. Any intake can require a new calibration. I don't see how two intakes, just because they're both "open filter," would make them read the same.

There may be some compensation tables based on high intake temperatures that pull ignition timing or change wastegate duty. If you have an intake that pulls hot air from the engine bay, it could cause the IAT sensor to read high and pull timing or whatnot. You'd need to check to see if there are such tables, and if your IAT changes, and adjust accordingly.

[C6ect.ect]

The whole point of a hot wire MAF is that it does not vary (much?) with humidity, temperature, and atmospheric pressure. By far, the MAF should react to mass air flow, not other factors.

You are absolutely correct Sir Freon . The unfortunate regard to this with EVO's however is that the hz value is afterwards adjusted by the baro table and temp table before ECU precieved load is figured.

I discovered something recently that was somewhat interesting. A year ago about the sametime I started datalogging I noticed unusual knock activity at low loads and RPM, from 5"Hg - 5 psi charge pressure (appx. 100% load and 2500 rpm). I spent about a year trying to find the source, from external "phantom" possibilities and engine harmonic, to tune and fuel. Found nothing.

About the same time I gave up on it, and for another reason I decided to change my MAF scale and smoothing tables back to the original OEM values. They have been this way for awhile, for about as long as I've been datalogging. The first drive with the tables defaulted I immediately noticed a marked decrease in part-throttle/low RPM knock, about a 50% decrease in knock sum.

I'm about 80% confident that this was the source of the knock and my assumption on it's mechanism is a difference between actual and ECU precieved load where the knock filter made it over sensitive.