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Old 01-20-2019, 02:47 PM   #1
Bchase1
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Default MAF Scaling for k&n intake

Iím having a hard time getting my maf scaling done, wondering if anyone has this intake and would be willing to share there scaling table. Or if anyone has any idea how close the Cobb sf intake scaling is compared to the k&n typhoon. Appreciate any info thanks
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Old 01-20-2019, 04:47 PM   #2
JSR84
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What process are you using to calibrate it? I have seen threads and videos relating to the K&N being difficult to nail down a calibration due to some design issues.
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Old 01-20-2019, 05:14 PM   #3
Bchase1
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Iíve been using accesstuner and been adjusting based on A/F corrections, Iíve read a few threads about using RomRaider tools and others using excel spreadsheets but cant seem to get either to work for me. Considering just replacing with a Cobb sf
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Old 01-20-2019, 05:44 PM   #4
JSR84
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Quote:
Originally Posted by Bchase1 View Post
Iíve been using accesstuner and been adjusting based on A/F corrections, Iíve read a few threads about using RomRaider tools and others using excel spreadsheets but cant seem to get either to work for me. Considering just replacing with a Cobb sf
That would be a good move in my opinion.

This guy explains it well...
https://youtu.be/wbmDuh8nvNg
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Old 02-05-2019, 02:20 AM   #5
slow.wagon
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The process is pretty easy actually, its just requires a few minutes and basic skills with excel. Before you even try it, make sure you do a couple things.

First measure the ID of the new pipe. You will need to make a basic cross section proportion multiplier to get the stock MAF table close to accurate values for the new pipe. If the new pipe ID is 72mm and the old ID is 63mm, use the following formula:

(12.56636 x (72mm/2)) / (12.56636 x (63mm/2)) = 1.142

Multiply the entire MAF g/s row by 1.142.

This is now your starting point. Your fuel trims will still be off but this should get you within the ball park. Next you have to flash the map, then log the following parameters (assuming you have rear 02 fuel trims disabled):

AF Correction 1
AF Learning 1
MAF Volts
Boost (Manifold Rel Pressure)
Closed Loop Switch
Throttle Position

Go take a very gentile drive, stay out of boost and just get a lot of data. Try not to shift through too many gears. Just putter around and make as few gear changes and throttle changes as possible. Its not as hard as it sounds. Things you will need to filter out from the log:

Any situation where you are not in vacuum, or where you greater than 20% throttle is applied or where you are in open loop. I suggest sorting the table and deleting all rows that meet that criteria.

Create a new column in the spreadsheet call it "Total Correction Multiplier" or something sensible. Set the values of this column to be:

(100 + AF Correction 1 + AF Learning 1)/100 = CL Correction Multiplier

You will need to apply this formula to all rows in the Total Correction Multiplier column.

Insert a Pivot Table using the "MAF Voltage" and "Total Correction Multiplier" columns. Make sure in the Pivot table you use set "MAF Voltage" as the Row Label and "Total Correction" as the Values. Configure the "Summarize value field by" settings for "Total Correction" to be the "Average" (it defaults to Count). If you don't know how to do any of that, you need study up on Excel.

When you get the Pivot table working, you should have a a two column table with one row showing the MAF Volt and the other showing the average of Total Correction Multiplier values found at each MAF Volt. Basically just walk the table by finding each MAF volt defined in ATR and multiply the associated Total Correction Multiplier value by the g/s value. You likely wont find all the voltages as defined in ATR, in some cases the voltage will skip over a defined value due to MAF sensor resolution. Some folks take some type of average to arrive, others just leave it alone (I do the latter).

When you get all your applicable MAF values adjusted, I usually go back and look for non smooth transitions and apply smoothing in ATR. I have found that if you let the MAF table get too lumpy, your car will swing between lean/rich values causing weird correction oscillations that take a long time to get settled and it just screws up subsequent data logs. A smooth curve prevents this and allows the fueling system to make more gradual changes with airflow. You don't need to get too stupid with smoothing, just get the lumps out and concentrate on gathering data and making gradual adjustments. You will likely have to follow this procedure several times before you can get the car within +/- 3-5%.

If you find that you just cant get it right no matter how much data you collect, you probably have a leak or some other mechanical problem. You might also have other areas of the tune that are messed up but thats highly unlikely if you have never touched the map before.

If this is all too overwhelming, just share your MAF table and the data logs with the items above and I'll help you out.

Last edited by slow.wagon; 02-05-2019 at 09:42 AM.
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Old 02-05-2019, 10:47 AM   #6
86Dreams
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Be prepared to spend a few hours on this and to revisit it when the weather changes. Be prepared to be sitting in your car on the side of the road. Be safe and obey traffic laws.

First disable closed loop fueling and run open loop only, you DO NOT want to use the front 02 sensor fuel trims until after doing the following.

You need to use a wideband and log it against comm fuel final and fueling primary open loop map, the open loop map fueling will be your primary point of comparison.

You need to log constant throttle sweeps trying to get through as much of the maf voltage range as possible. This does not mean wot pulls. Stop logging after each pull.

You do not need to disable tip in enrichment, you need to accelerate slow enough to get past the enrichment event so that it is not throwing off your readings.

after that adjust the maf for the fueling error and repeat the process as many times as needed until you feel that fueling is within the tolerance that you would like.

Keep an eye out for rpm ranges that you cannot get correct, compare them against MAP to see if there is a trend and adjust the manifold pressure compensation table if necessary. Do not just jump straight to this.

Once you have the maf dialed in use the spread sheet in this thread to smooth it out.

http://www.romraider.com/forum/viewt...p?f=32&t=13450

Afterwards reenable Closed loop fueling and make further adjustments as necessary
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