ECU Tunes and Installs

[mizone]

It's got a DoS based F9 fuel only computer. I had to do some trick USB serial pass through to dosbox to get the software talking, ..... .

Been playing around with getting VM's working in Windows 10 for the Siemens controller guys at work. Take a look at VMBox. I was able to run W10 (64 bit) with Windows 7 32 bit and WXP running a USB to serial converter quite easily.

All Freeware GNU.

[Jason Broadhurst]

That is nice software :D

I know all about Siemens PLC's and DCS too, I moonlight at a control system engineer between tuning

[trdee]

this is a bit of a question for the adaptronic guys: copied from my thread -

Got my car back from the tuner and the AFRs are very inconsistent especially as the engine transitions on to boost. Had a look at the maps and it doesnt seem right to me. Andy at adaptronic specifies how to tune ITB turbo cars here:
https://youtu.be/vx0EfooQVBk?t=283

The basic summary is - the bulk of the tune is done in the "TPS" fuel map. The "MAP" fuel map is only used for corrections for higher boost level and is a multiplier of the TPS map, so everyt. Say for example your low boost is fairly tame, so your AFR at 100% throttle, low boost is set to 13:1 and the "MAP" table should be set to 1.00 IE it does not make any corrections to the TPS map at low boost, 100% throttle.

Then, on high boost, you are pushing the engine a lot harder, so you want to drop it down to maybe 11.8:1. In this instance, the "TPS" value at 100% throttle cant be different for different boost levels, so for high boost you increase the "MAP" value at your higher boost level to maybe 1.2. This will multiply that original "TPS" value by 1.2, thereby adding 20% more fuel, and giving you a richer mixture at high boost

Now, with this in mind, check out my TPS and MAP fuel maps:






Now I might be wrong here, but it looks like the corrections in the MAP table are way too extreme. It looks like the bulk of the tuning has been done in the MAP table, which is always going to be tough since very small numbers are gonna mean a big incremental change to the tune, since it is a multiplier of the TPS table. There are sections where the MAP table goes to 1.6, which is adding 60% more fuel, even though this tune was done at wastegate pressure (200kPa/14psi) and thus you should be able to just punch everything into the TPS table only since this level of boost is very mild and doesnt need extra enrichment over what you would put in at 100% TPS anywhere in the map

Might explain why the tune is so inconsistent and the tuner had so much trouble getting it good.

[10sec rx7]

When tuned in ve there are 3 things that are required to get correct tuning, target afr, main ve table and map correction, 9 out of 10 times when everything in correct you will hardly touch the map correction table as the ecu *should* know what the desires afr is on the target afr table and make corrections based on this, map correction table should only then require a few % each way

[trdee]

that is how i understand the system to work as well. with that in mind the above map correction table signifies something is massively wrong either with the car itself (fuel pressure issues maybe?) or the way it was tuned

gonna get a fuel pressure sensor and wire it into my dash, just as an extra analysis tool

[10sec rx7]

It would indicate either there is a mechanical issue or the ecu has not been given the right information

[10sec rx7]

Or the tune is just not right

[trdee]

given there are even map correction values at idle i would assume the latter, but yeah will do some more testing. i am kinda suss on the fuel pump wiring which is why i wanna get a pressure sensor on there.

[10sec rx7]

yeh fuel pressure is great to keep a eye on, i dont do a huge amount of adaptoronic but if you need some help just ask, Jason would know more about the modeling etc but between the 2 of us we should be able to get it sorted for you

[trdee]

So I added the map correction values to the TPS map, and cleared the MAP map back to 1.000 across the board. Given that there are different values for different manifold pressures, I chose a hybrid approach and used the MAP corrections at 100kpa for 0-30% throttle, and 200kpa for 30-100% throttle. It's obviously going to be wrong in parts, but the tune was inconsistent anyway, and now I can tune the entire thing in the TPS map like it is supposed to be done, rather than chasing my tail with MAP corrections.



What I find interesting is that in the top end the VE values now look a lot more like what you would expect from this kind of engine. For reference, the silvertop 20v I was previously running in this car, and had tuned on a dyno myself, had VE values of around 115 in the top end of the map which is similar to what you see here. This indicates that there is likely no issue with fuel pressure etc, otherwise I would have expected the VE values to be fudged to a significantly higher set of numbers to make up for a shortfall in fuel pressure etc. The 6krpm area does have VE numbers go sharply higher for a brief period, however also was reflected in the wideband reading significantly richer there too when I drove the car. Im guessing with VE values closer to 110-115 the AFRs are going to be in the right ballpark.

Will go for a burn tonight to verify. Hopefully this will get me closer to a more consistent base to tune from

[dnegative]

I did say if it wasn't a power FC on a SR20 they would be up shit creek lol

[Jason Broadhurst]

That's not really how to tune any ITB ecu by the looks.

You should have very little to 0 correction in vacuum and then have the map tuned only on the MAP correction map for on boost.

It might work, but it's not good practice.

Also, a smooth map is a good map. Spikes just scream lazy or another setting like dead time or something in the VE calc isn't correct.

[10sec rx7]

This is a ve table off a r33 Gtr I did a few weeks back, map correction is off all together, actual afr matched target perfectly, map correction should be so small it's not needed, if it's large you need to fix your injector data or fuel model

[trdee]

I ran the car with my "fused" TPS map last night. Drove exactly the same, so that tells me there was no reason for him to tune it the way he did and the inconsistencies are just in the tune itself. As you guys say, there shouldnt be any numbers in the MAP table, especially at idle/low load.

Unfortunately I have also found that cylinder #4 is fouling up, and my idle wont drop below 1400rpm even with no input from the idle motor, so that probably explains part of the inconsistency
Might rent a dyno like last time and tune the fucken thing myself.

[Jason Broadhurst]

For clarity, most VE calcs in TPS/MAP blend mode will use the MAP table as a fine correction. The MAP is already a function of VE, so like Dale said, it's not really required.

Much like the IAT correction table in most ECU's. The VE calc uses IAT for density based on 0 degrees kelvin and corrects for it. Using the IAT correction table is not really required with a proper VE model, unless you want to have a over corrected mixture (which is desirable sometimes)