Digifant II Performance chip (with actual gains) - Who'd be interested?

As in the title, if there was a chip available for digi 2 that actually improves performance (unlike many eBay chips) would anyone be interested?

Its a few months away yet and a lot of work but the features it would have are:

• Full Fuel map re-calibration
• Timing re-calibration (No chip currently available does this)
• RPM limit increase if desired
• Blue temperature sensor map changes to reduce performance drop when warm

Further features (if I can be bothered and there is demand):

• Twin maps using an external switch to control
• Enable Oxygen sensor (would be narrow band)
• Actual Diagnostics that work
• Ability to remap with ECU still in the car
• Wibeband/CAN bus support/Internal MAF conversion (Really pushing it)

Anyone that's read threads on this ECU before has most likely seen something along the lines of "You can't change the timing on Digifant II" or "It should be Digicrap, just put it in the bin". This isn't correct you can change the timing, although it requires it requires reading the Motorola timing MCU which is challenging. If I succeed at this, all of the above will be possible.

 

Yeah that would be the idea! To be honest its more of a learning experience for me, just to see what I can out of it. The CAN-BUS idea would only be implemented if I was going to add wideband, so you could use something like a Haltech CAN wideband controller, plus I think it would be kind of interesting running a protocol on a processor that's actually older than it

And there's two routes I can go with Diagnostics. The ECU has hardware to do "Blink Code" diagnostics which gives some basic functionality, however I'm yet to check if this is enabled in software. But if I were to add external mapping I would totally re-write this and convert it to work something like K-line

 

The diagnostics is fairly limited as the ECU cannot store its codes like a modern car can. However, it should be able to do simple things like tell you if the temperature sensor or knock sensor is misbehaving. I've had a very quick look at the code and it check the status of the "Diag" pin during startup, so I would assume it should do something. Once I get my car back on the road I'll have a go with it.

 

What sort of gains are you talking about? I thought with the 2d map in the Digi, no TPS, no crank trigger, batch fired injection etc, there wasn't much to be gained?

 

I should rephrase title, the overall power gain would be similar to what you could achieve with Megasquit, however the difference will be in how power is delivered. And as @rubjonny said it would give you the ability to have a ECU that actually matches your mods while still keeping the factory management. The AFM could also be quite easily converted to a TPS like @Toyotec did in this thread.

 

I put a Ford TPS on my own butterfly spindle. No point putting it on the AFM.

I hope it works. Still lots of Digi lovers out there.

 

Ahh no I meant removing the AFM and converting the AFM input to use a TPS a instead.
And cheers!

 

I'd find this of interest, not least from an intellectual process.

Whilst I don't have one as a daily driver, our Digifant is for my daughter as her first car and we've been having fun building it up. If you need any help or assistance with it then let me know. Sure I've never changed code for a car like reprogramming it but have a lot of experience with other systems. Might even have some ideas on how to store fault codes.

 

Thank you and yes definitely I'll let you know! I've got 3 donor ECU's coming over the next week, 2 of which "Don't have chips" and 1 that is sealed but of unknown condition. I'm hoping that the seller means the 2 simply don't have EEPROM's as these can be easily replaced, and the Motorola Ignition processor is still present, as that is part that is going to be the hardest and most challenging to reverse engineer.

Progress on this will most likely be quite slow as I've got to fit it in in my spare time, but I will try and update this thread as regularly as I can with major progress updates, and keep the smaller and more in-depth updates on my website.(This is a car forum after-all, not a computer science one )

 

Could be interesting, good luck with it and keep us updated.

 

Just got my donor ECU’s in the post, they are all 037 906 022 N, and as expected, have had their EEPROM removed but timing controllers left in tack.

Now, my car has a Siemens 037 906 022 FJ, which I believe was a warranty replacement. So does anyone know the difference between the single and double letter units? Or which part is most common?

It seems that most existing chips work only with double letter ECU’s

 

The statement "you cannot change timing on the Digifant 2" is partially correct as it requires specific folk like your self to find an off the self solution for a tuner.

I used to tune an 8v PGTI car.

I could only adjust the fuel control and had no access to tweak the timing which was critical. That is why these ECUs are usually binned when you are after controlled performance increases.

On the race car, because we were not allowed to change a lot except for a control cam, in the end I went from a typical 115 lbft @ 3400 rpm and 112 bhp @ 5500 to an engine that was at 126 lbft @ 3800 rpm and 123 bhp @ 5800 rpm on more optimised AFR tuning and dizzy rotation alone.
The fuel duty was almost max at 6400 rpm and the lambda would track off lean.
Fuel flow aside, it would have had more performance if the spark timing could have been mapped for sure.

I can see this working on an engine with a bit of compression, cams and larger injectors. I have seen performance gains in those when using SEMs.

 

Only gains I see here is you would not have to replace your ECU and deliver the same levels of performance if it was a SEM.

 

This is would be the goal yes, similar performance to SEM but with lower cost/effort to end user.

For anyone that is interested, I thought I'd just post a couple of pictures of one of the ECU's that arrived. As you can see I've opened it up, and folded out the boards. The top board would normally house a Motorola processor to handle ignition, and the lower board contains the main Intel processor and fuel map containing EEPROM. As you can see however, the chips are there, just not in their sockets, and the plastic retainers have also been lost. The construction of ECU is quite interesting as the main processor is from 1977, and was commonly used in keyboards, but there is also the extensive use of surface mount components on the rear. The fact the design also uses two discreet processors, with totally different instruction sets and quite literally from different eras is also odd to me. It strikes me as being far more costly to develop than something like Digifant I that does the same as Digifant II and more, while only using one CPU.


These are close ups of the chips, they are in ceramic packages which makes them very heavy and "cold" feeling compared to modern plastic IC's. The stickers are there to prevent light entering the window on top of the chip and erasing them inadvertently.

 

It kinda seems like it is two separate ECUs, an ignition ECU and a fuel ECU in a single box.

Is there much/any interaction between the two? Or does it just pass through the ignition related signals and output to the ignition board?

 

Yeah you're exactly right! There is only one communication wire between the processors and I believe this is simply used for one to tell the other when it sending diagnostics codes, as they share a common line. Apart from that, the processors are totally unaware of each other.
As I said before, this approach would have been incredibly costly for Bosch as it would have needed two development teams that could work with the two processors. All I can think is that the "Ignition" board, is actually just a 16V Knock controller "Knock Box" that they had already developed, so they just used that and made a fuel processor to go with it. But then again, they had Digifant I so why didn't they use that? And why use a 15 year old keyboard processor for the fuel when they clearly had the ability to work with a much more Motorola device?

Its all very confusing to me

 

The injection side may be based on Digi-Jet?

 

Genius! I hadn't thought of that! Just had a look at some pictures online and Digi-Jet does in-fact use the same Intel Processor and ADC and Digifant.
Has anyone got a picture of the inside of knock box? If those internals are the same then it would appear Digifant II was just a parts bin special.