Hello everyone
I am currently trying to tune a NA engine with Alpha-N. It is not equipped with MAP sensor, and since I’m planning to mount ITBs, I don’t plan on mounting it nor using the built-in one. At least I think I don’t need it (I’m still learning).
I have noticed that to be able to use:
- Autotune tool
- EGO feedback
I have to provide minimum and maximum MAP sensor pressure value.
In my case, because it is not used, the MAP value is just = 0 all the time.
But the program requires some minimal value in both tools, I cannot just put 0 there.
So because I never get into the required MAP range, the result is:
- No data in Autotune
- No EGO corrections
What do you suggest should I do to be able to use those?
Use the built-in MAP connected to nothing?
Or is there a way to hardcode a MAP sensor readout?
I know those would be just workarounds, but I can’t find a proper way to use the two tools mentioned without using MAP sensor.
The minimum and maximum MAP values for EGO corrections are just there so that if you have a map sensor and let’s say you didn’t want to apply EGO correction below 30kPa or above 90kPa, you’d still get correction between 30 and 90kPa. In case of using no MAP sensor, you’d just set the minimum to 0kPa and the maximum to 200kPa and you’d have EGO correction active at all times.
As for Autotune, when you’re using Alpha-N, the Autotune table matches your VE table or Lambda/AFR table, i.e. it has TPS% on the x-axis and RPM on the y-axis. In the software on your laptop, I’ve noticed a glitch when switching from speed-density to Alpha-N in the middle of a tuning session - the Autotune graph sometimes continues to display in kPa rather than TPS% on the x-axis. If that happens, just save, close and reopen your tune file and you should see the Autotune map changed toTPS%.
Hope that makes sense.
For a street car, personally, I’d hook up a vacuum line to each manifold runner and add a MAP sensor - you can also use the vacuum lines to plumb in an IAC valve (for cold starts and a smooth idle) and to add a vacuum reference to your fuel pressure sensor. The MAP sensor allows you to make use of the advanced Alpha-N tuning strategies where you use MAP to add in ignition advance and increase AFR/lambda values (great for saving fuel when cruising) and helps in adding torque at partial throttle openings.
Thank you for your answer, and benefits of using MAP, however I’d like to try keeping the bare-bones setup for now. Here’s the deal with EGO correction settings: I cannot set it to min=0 ; software throws the following error:
I am running ecumaster software version “1.218 Exp. 1”, meant for emu classic hardware.
Could you tell me what SW version are you running? And if you are able to set min MAP to 0 in EGO Feedback window?
Set it to 10 and you should be good. I think i’m on 1.227 or 1.228 now, but shouldn’t make a difference. If you haven’t got any vacuum source plugged into the MAP sensor, it will just be reading atmospheric pressure, i.e 100 kPa at all times.
Yeah, I think I’ll do just that for now. Thanks for your input!
It does look like a bug that could be fixed, maybe to have a separate flag saying “do not use MAP”, so we don’t use the sensor for nothing like that.
It’ll work fine. Normal range for atmospheric pressure will be about 98 to 101kPa, maybe a bit lower in high mountains, but nowhere near 10kPa.
good luck with the tune and don’t be afraid to ask questions..
