Nistune Forums

See first post. Adjusts fuel maps based from targets using wideband data

Yes, I read the first post - it is still not clear to me!

And sorry for repeating myself, but what does this actually do???

'Adjust fuel maps based on targets?'

What is this good for??
Is this meant for setting K?

Can you give me a context?

Matt wrote:See first post. Adjusts fuel maps based from targets using wideband data

it saves you time, its a great tool.

you enter what you want your car to run at in terms of AFR. Select the cells in the map which you want nistune to auto tune for you. and let it run while you do some pulls.

Nistune will look at what the wideband o2 is logging at these cells, if you are actually richer than the target it will pull fuelling and if your leaner it will add. like i said its a great tool to create a decent fuel map within a few runs. no need to log, do a pull, edit, redo run, edit....

Hi there,

Thanks for pointing this out.


But let's assume I set up K correctly and I verified that by using my wideband. (which I did)

What use is AutoTune then?

If real world AFR differs from the values in the map it only means that
the model the ECU has is incorrect due to an error further 'upstream'.
(K, VQ, XYZ)

But you would not correct such an error in the fuel map, would you?

Maybe the confusion stems from the fact that I tune 'AFR' and you guys might
use RAW values and a WideBand.

I tend to make sure that the ECU's model is in sync with real world.


But maybe I still just don't get it

s200rat wrote:it saves you time, its a great tool.

you enter what you want your car to run at in terms of AFR. Select the cells in the map which you want nistune to auto tune for you. and let it run while you do some pulls.

Nistune will look at what the wideband o2 is logging at these cells, if you are actually richer than the target it will pull fuelling and if your leaner it will add. like i said its a great tool to create a decent fuel map within a few runs. no need to log, do a pull, edit, redo run, edit....

i use raw values.

Setting K value correctly then playing with target A/F map is only part of the process.

Too much variables going on within the engine to assume that a theoretical calculation of the amount of fuel required will actually give you that across all conditions/rpm's. if your engine does then great, it will make your life easier.

Depending on runner length, boost, temp, injector nozzle design only a % of what the injector fires will find its way into the combustion chamber. hence the need to adjust raw value to get your "actual" desired ratio. Thats where the auto tune script is handy.

Hi there,

Thanks, I now (finally) got the message

I was just thinking in the wrong direction, that's all.

For the fun of it I will try AutoTune on my next run.
Let's see how out of line ECU and real world is ..


(On my last run AFR looked actually quite good)


How much of a difference did you experience when you compared Wideband to AFR?

the likes of +/- 0.3-0.5 off of theroretical in certain areas of the map is what ive seen

That's not too dramatic then, and it seems you did a good job at calibration beforehand.

So (though missine a VE table) the Z32ECU does a good job at estimation.

(After all that's the design goal of an ECU)

It is necessary to change the autotune, fuel card must be constant real time setting. And all the changes should be in a different window.

keep in mind that any form of auto tune best kept for steady state rather than inertia tuning.

variables like position of 02 sensors, acceleration, sensor controller design etc can cause unpredictabiltiy..

Im gonna play with this when I get home this afternoon!

What does the VE and VQ map adjust mean?

VE tuning is not available

VQ Map will adjust the vq map points depending on lean/rich conditions

I tryed it this afternoon and it was adjusting the maf conversion? Car idled rich and then cut off. I disabled it and reset the maf table and tuned from scratch. Am I only suppose to have tbe fuel map open only?

You must be running with 0.10.17 version or later

I tryed it again this morning and it worked with just the fuel map opened. Where can I find the 0.10.17 version? I didnt see it under Software downloads? I have NIStune Version 0.10.13R (EXE)

And exactly how do you use it?? Are you suppose to keep the speed and rpm's steady or something??

thanks