Re-scaling load in fuel and ignition maps.......

[Kha0S]

high rpm listening isnt too much of a neccessity but adjusting the load parameters is. peak cylinder pressure occurs at peak torque, this is also where you're most likely to get det so keep the ECU listening to the stock knock sensor incase you're running maps that are too aggressive. det at low rpm is the most damaging.

That makes perfect sense, thanks.

[Mo]

Calvin, log attached for your reference.

[Navybluesubaru]

I swear I started a topic about this just the other day but I cant find it...anyways...

I was wondering the same thing; is anybody scaling the load columns for their fuel/timing maps. I have mine scaled up to 5.5 so far, linearally starting from the original first value up to 5.5. I can see over 5.0 at just 10psi at certain rpm's. I am tuning the car, starting from as little boost as possible and working my way up, hence the low boost. If I am running my normal 22psi I would probably see load in excess of 6 and maybe even 7, who knows.

What are other people doing, scaling linearly? Any problems so far?

Jeff

[Mo]

I re-scaled the later half of the tables with increasingly larger increments leaving the the lower regions unchanged, if you lose resolution here you'll effect your part throttle response possibly producing something quite jerky and not very nice to drive.

With the standard inlet running 22psi on a 2.5ltr I regularly see 7.99

[FrSTi]

I re-scaled the later half of the tables with increasingly larger increments leaving the the lower regions unchanged, if you lose resolution here you'll effect your part throttle response possibly producing something quite jerky and not very nice to drive.

With the standard inlet running 22psi on a 2.5ltr I regularly see 7.99

Hummm. It looks like you are hitting the wall then...
It is time to consider a rescale, why not using a bigger MAF tube ?

[defusionus]

Thankyou for the that Calvin, I'll report back how I get on with the re-scale. I still don't have my laptop back so used a friends to get this pull today........

Mo what software are you using to log?

[swifty]

I have changed rescaled tables before but only the existing column or row values. Is it possible to add rows or columns too ? Are there any limits ?

[Freon]

You can't add rows and columns, only rescale the existing ones.

I guess it is possible, but it would entail reprogramming the ECU. I don't think there is a need. There are enough columns and rows. The ECU interpolates between points. I'm pretty sure at least the timing maps are bilinear. (i.e. blends the four closest map points).

[west_minist]

There is a need to add columns and rows, especially columns.

I think this is what EcuTek is doing now to support over 400whp.

There is no way you can support 400+whp in stock maps properly.

I am working on a WRX 2.0L export model now and he is almost doing a load of 5. A far cry from 4.28

A nice move from 18x16 to like 20x20, 24x24 or 32x32 for fuel, ign and so on would be great.

Is there a way to push data down the data in the rom and still have references to the new updated tables?

[Freon]

4.28 to 5 is nothing! You can easy rescale the existing maps to make that work.

I really think there are enough data points in the stock ECU. Just stretch them a bit, its fine. Stock my maps only go up to load of 2.75 or 2.9 (keep in mind this is a 32bit ECU, that is like 5.5 to 5.8 on a 16bit). I have them extended up to 3.6 (7.2 on a 16bit) now. It works just fine!

Here's my main timing map (stock compared to modified/expanded/tuned)
http://freon.shackspace.com/car/ecu%20a ... tretch.png

FWIW, it will not be complex to make some maps bigger. Some sort of program to help do this would be nice. Just need to make some other maps smaller and make sure all affected shuffled maps are correctly referenced in the code. The map definition areas in the 32bit ECUs make this pretty easy, since. Still would be time consuming by hand. There are many, many maps that are just full of zeros or large 2d or 3d maps that have the same value in the entire map that could be scaled down to make room, easily.

[west_minist]

I know to 5 is small and to 5.6, but then you lose the resolution you want.

That would be nice to move from the present resolution.

The rom also have a lot of waste area.

I wonder how EcuTek is doing it.

[Freon]

I doubt ecutek is doing anything at all. You're greatly overplaying it. It's not a big deal. Just stretch the map carefully.

There is no getting around large potions of the map being unused. I.e. highest loads at low RPM. That's just life.

[Jon [in CT]]

If you're running a 2002-3 US WRX ECU and you need bigger maps for fuel and ignition, you should consider using the A4SG900C ROM, the one used when the US 2002 WRX was manufactured. The larger maps are described in thread http://forums.openecu.org/viewtopic.php?t=265 and the ROM image can be downloaded from http://forums.openecu.org/download.php?id=59.

[west_minist]

Unfortunately Jon, these are on JDM, including others.

But it is an interesting topic and as time goes by, we will see what will happen.

[m3n0ch3]

hmmm isn't it running for trouble flashing with a different map size your own rom?