ex MPSer
You'd just do a MAF calibration to customise the tune for their intake and TIP or whatever combination you're running. When you have made that tune you could add it to the database and share it with others who want to use the same setup.Originally Posted by High on PSI
Forum Addict
Sending the calibration over email?
ex MPSer
No, you can do the logging and alter the tune yourself, but if you're really unsure I'm sure if you posted the logs somewhere somebody would help you out...
The VersaTune help file covers how to do a MAF calibration, but here's what it all means.
The Mass Air Flow sensor measures how much air is coming in through your intake in grams per second, and converts this to a signal in volts (MAF Voltage) which is communicated to the ECU. The ECU then injects an amount of fuel based on the MAF Voltage (i.e. amount of air coming in) in order to achieve an actual Air to Fuel Ratio in the exhaust (Actual AFR) which should match what the ECU is commanding (Commanded/Desired AFR), read using the oxygen sensor/s in your exhaust stream.
There are two operating modes for fuelling that the ECU operates in, called closed loop (pottering around town, cruising on the highway) and open loop (generally wide open throttle).
In closed loop operation, the amount of fuel to inject is based on a series of lookup tables within the ECU known as the Long Term Fuel Trims (LTFT). There are five LTFT tables in the ECU, each for a particular MAF Voltage range. In order to keep the Actual AFR and Commanded AFR as close as possible, the ECU applies Short Term Fuel Trims (STFT) either adding more fuel (if Actual AFR is leaner than Commanded AFR) or pulling fuel (if Actual AFR is richer than Commanded AFR). Over time the ECU "learns" if these differences are consistently too large (up to a point) and the LTFT tables are updated with minor adjustments derived from the STFT numbers.
So what does this have to do with MAF Calibration? You can speed up this process and ensure the LTFT and STFT numbers are as close to "0" as possible (which is ideal) by comparing the MAF Voltage, Actual AFR and Commanded AFR and LTFT to see how far off Commanded AFR the Actual AFR is for a given MAF Voltage, and see what LTFT adjustment is being applied. Ultimately the goal is to target the areas where your logged LTFT figure is greater than say -8% to +8% and adjust the tune so that the LTFT doesn't exceed these figures. Some people are more anal and will aim for -4% to +4% or even -2% to +2%. Trims vary with weather, fuel etc though.
When that is all done and working, meaning the the amount of air coming in the motor has correctly been adjusted for, your LTFTs are good and your Actual vs. Commanded AFR's are spot on, you can then tune to meet specific AFRs during open loop operation, which only relies on the MAF Voltage in order to know how much fuel to inject to hit the Commanded AFR (no fuel trims are applied).
I know how much some people hate reading, but I do encourage a bit of a Google search and read about it if you're genuinely interested in properly tuning your car! Otherwise pay a professional or just rely on the off-the-shelf tunes
Forum Freak
Tactrix unit arrived today. When I get a spare minute I'll purchase the Versatune software, hopefully it's an immediate download. With a little luck I'll have the first Versatuned 6MPS in Aus (that I know of) by tonight. I've been waiting five years for this, since the guys in Ukraine first cracked it.
ex MPSer
Good stuff!
Forum Addict
Good luck Mal.
Let me know how it goes cos i might ditch the Ezy-flash and give this a try
ex MPSer
Oh, I forgot to mention Mal, once flashed on the base tune and the fuel trims are settled get onto the MAF calibration. The 93US/98EU base tune Steve has done for the 3 was pretty good straight up, but a slight tweak for our fuel and environmental conditions brought the trims in quite well on mine. I'd assume the base tune for the 6 will be similar.
ex MPSer
Thought I'd post a quick update.
I'm still working through the Verstauner software trying to wrap my head around it all! Over the weekend I've had a major configuration change by finally adding an aftermarket downpipe, so now I'll take the opportunity to alter the base tune and customise it to suit my car.
Steve's base tune is a load based tune (aiming for load targets), not a boost based one like many of the guys in the US are doing with the Cobb ATR and AP setup, so I've decided to play it safe and stick with the load based tuning philosophy. Will be more complex to do but should give a better result overall with the added bonus of knowing that the load limit safeguards I set will be in place to prevent 'zoom zoom boom' provided I'm not silly with where and how high they are
Forum Freak
I'm in Melbourne for a few days wishing I was at home playing with my new toy. Had a quick look at versatune before I left Perth and wondering where all these uploaded tunes are found - I've only had a dozen or so show up. Is there a bigger list of available tunes hiding somewhere?
New Member
This looks very interesting. Thanks for sharing TD
Nowadays I am very fussy when it comes who works on my cars.
This looks like one i could do without getting lost.
Forum Addict
When this gets installed on 1 computer, can it be installed on another? (The tuning software)
ex MPSer
Yep, the software can be installed on multiple computers, but your copy is locked to your VIN.
I have it on my work computer and on my netbook. Has been handy having it on the work computer to help learn
Stay at home dad FTW
how does this go with aftermarket turbos??
ex MPSer
Would be a good solution for you Will, but you'd need to put in some work to tune everything.
Stay at home dad FTW
so would be better than paying 2100 for the custom flash tune at CT??? hmm sounds good but i think the lack of my knowledge might be not a good idea unless someone wants to help me
ex MPSer
$2100! Damn...
What turbo are you looking to get? There may be others with 6MPS's running a similar setup who have Versatune already, which could provide you with a starting point.
I'm wrapping my head around the software now too, so would be happy to assist where possible.
Stay at home dad FTW
Looking at 2876R I jus can't decide
New Member
Versatune have just announced the release for the Mazda 3 MPS software with support for Australia
ex MPSer
Well spotted!
A bit of an update on my progress with VersaTune. I was building my own high load tune and then a base high load tune became available in the shared tunes area so I grabbed that and transferred my MAF calibration and the Boost Control Solenoid (Waste Gate) duty cycle settings over to that map.
Went for a drive last night after writing the high load tune to the car, took it easy for 50km so the fuel trims could settle again then put my foot down. Wow! The MPS grin is back
There's still more room in this tune, but I'm going 'slowly slowly' with my changes. I keep running out of road when logging so don't get to safely do any log above 3rd gear. Might need to chuck it on a dyno and run in 4-6 gears to finish off the tune, or find a 'private road' somewhere. That could be today's project...does anyone have a spare runway they're not using for a morning?
Fabrication Yoda
Yes, use mine
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