MAF scaling like a boss with cruise control

[phrosty]

Last night I was reflashing and decided to see how quickly I could approach Perrin's provided MAF scale when coming from OFT's OTS 2.0 values. Last time I scaled my MAF it took three 1+ hour runs over a couple weekends. So, I went back to OFT's values and hit the road.

Open loop scaling was the same procedure, just do some pulls -- but for closed loop I was a bit more methodical about it, taking the "steady driving" idea a bit further. I decided to use cruise control and go up 1mph about every 30 seconds. Not too difficult to maintain a speed for 30sec if you do this later at night when not many people are on the road.

Result is a scale that was within 2% of Perrin's provided one in a single one hour go. Very nice! I did this with my own custom scaling code that filters out a bit more than what tutorials/vgi do so YMMV, but I'm curious if this will work for others.

[BuBlake]

Originally Posted by phrosty

Last night I was reflashing and decided to see how quickly I could approach Perrin's provided MAF scale when coming from OFT's OTS 2.0 values. Last time I scaled my MAF it took three 1+ hour runs over a couple weekends. So, I went back to OFT's values and hit the road.

Open loop scaling was the same procedure, just do some pulls -- but for closed loop I was a bit more methodical about it, taking the "steady driving" idea a bit further. I decided to use cruise control and go up 1mph about every 30 seconds. Not too difficult to maintain a speed for 30sec if you do this later at night when not many people are on the road.

Result is a scale that was within 2% of Perrin's provided one in a single one hour go. Very nice! I did this with my own custom scaling code that filters out a bit more than what tutorials/vgi do so YMMV, but I'm curious if this will work for others.

Nice! That 2% difference was probably due to them having a dyno. Have you tried using a virtual dyno before to build or modify tunes? I have heard they are not worthwhile.

[Wayno]

What if you forced 100% open loop then repeated?

[Kodename47]

Originally Posted by Wayno

What if you forced 100% open loop then repeated?

The only issue I could foresee is that at lower RPM that the delay of cylinder to O2 sensor is larger than higher RPM. You'd need to take that into account when collating the data for decent accuracy.

[Turdinator]

Originally Posted by Wayno

What if you forced 100% open loop then repeated?

I suggested doing this but also locking in just direct injection and running a fuel map of all 12:1 so as to minimise variables but was told it was a waste of time. I was also going to try balance the direct injectors relative to the port injectors. The only reason i didn't go ahead with it anyway was that I was on 1.6x at the time and the 2.0x maps were announced.