Nistune Forums

That thread on the MAP sensor is very interesting. Unfortunately for me I have very little (i.e no) experience on the ASM of an ECCS ECU. So for that reason I am going to do the conversion with a Microchip PIC which I have lots of experience with!

Ed

Just out of curiosity , which ecu do you run ? 16 bit sr20 type?

An external micro could do it, you would just be emulating MAF voltage instead of Q itself.

You will need to use MAP (2 for baro correction), RPM, IAT, and maybe even TPS in your algorithm.

You can tap into the 1 degree (or 2 degree depending on whether your referencing cam or crank) signal , the one on the outside edge, to provide a good frequency signal to your MCU.

Using this high-res count will allow you to have faster RPM calculation update speeds in your controller/pc software.

Its an 8 bit CPU.

I will use one Map sensor. baro correction will be performed on power up. My plan is simply just to emulate the MAF voltage. I now have a maf voltage VS RPM VS boost graph I created today, so its just a case of emulating that. I cant see that I would need TPS feedback. But yes IAT will be needed.

Ed

The reason I mentioned TPS is that you are probably going to want to incorporate some sort of acceleration compensation to your output signal, using this variable. The nissan MAF does a lot of the work when it comes to ECCS acceleration compensation, it has very quick update.

A map sensor will take much longer to respond to changes such as acceleration. Short of writing a dedicated fuel acceleration routine within the ecu itself, your going to have to compensate for this with your device.

I have never seen the fuel control of the 16 bit sr/ka ecu documented, perhaps like the ka24e it uses TPS for alphaN functions. If you could decipher the original control you may already have the features you need.

I'm just going to try it and see what happens. If I have to add TPS enrichment, then I shall come to that when I'm there

As I said earlier, I am unable to understand the assembler code of the ECUs I simply don't have the experience with it or any way to find this information

Ed

I'm just going to try it and see what happens. If I have to add TPS enrichment, then I shall come to that when I'm there

As I said earlier, I am unable to understand the assembler code of the ECUs I simply don't have the experience with it or any way to find this information

Ed

Ok well I got the SR20 running upto 2 bar boost. We were taking it to be dynoed again today to see how much we were running. But before we got there doing some final tests the gearbox ate itself haha!!!
Its seems its totally stripped all of the teeth of third gear, so that will be repaired and the car sold on. The 2 bar 400bhp+ target has been well exceeded and now its owner wants to try something else. Shame really but it would cost so much to make a gearbox strong enough its just not worth it.

Ed

Got my hands on another pulsar today, with a very similar spec of what the one above was.

It made 463bhp and 430lb/ft torque. Pretty good going. Would have made more too if the actuator spring was stronger.

Ed

why does the power go so flat, is it because it has standard cams limiting the airflow or something?

yes basically, also the wastegate spring is not strong enough so we believe it opening too + the 2.5 inch exhaust.

The Map-Ecu does everything you guys are discussing.

I'm going to piggyback my realtime ecu with a map-Ecu thats I've had lying around.

The airflow meter is not a serious restriction. There would be no real gain in the above case of swapping for a MAP sensor.