Forum » Build Threads » Audi 2.5 5 cyl, help me to choose the ECU

Audi 2.5 5 cyl, help me to choose the ECU

Build Threads

Keep everyone up to date with how your project is coming along. 

Page 1

Hi everyone, I'm from a tiny country in the eastern part of Europe where standalone ECU tuning is not what you can see very often. Currently we have just 1 person which can tune an ECU and do all the wiring as well. Knowing that he dealt before with turbo 5 cylinder Audi before, and that's actually is what he is considered best at, I was full of hope that everything should be ok.

Short story long, I am now convinced to change the ECU not just because i dont like the tune, but also the attitude and lack of respect toward a client who is actually paying money for this.

So here I am, already read some books about EFI tuning, currently finishing HPA's course on fundamentals of EFI tuning and definitely will watch everything else, as I have already got access to all the courses.

Eventually I am dreaming of becoming a tuner, being very passionate about everything that burns (inside the cylinder would be the best) and produces a lot of power :)

So here I am choosing now a new ECU, the main choice stays between EMU black and Vems.

Some pros on VEMS loads of turbo 5 cylinders set up and running well, fairly priced, probably easy to find info specific on tuning my engine, even know some people abroad running the same config as i do on vems.

EMU black pros - functionality, interface and good support so far, following their groups on facebook. I think currently a very good value for money. I can see that this particular ECU has a good potential, imho.

I am a bit afraid to start doing the wiring and then tuning it from basically nothing. Although there are couple of guys in my city runing EMU on their BMW's and maybe they can help me out with the wiring, but certainly not with the tune.

I should mention again that currently on my Audi I've also got a standalone ECU, with custom wiring, which maybe can be difficult to correct or re-wire everything all over again. I am not willing to ask for anything from the guy who was tuning the car until now for personal reasons.

Should I just go for it and remove the old ECU, do the wiring again and install EMU BLACK? That's basically is what i am willing to do.

Or should i choose vems where i can finfind much more support on this particular engine?

Here's my build

Audi UrS4

2.5, stroker diesel block, 280 260 cams, solid lifters, light flywheel

gtx 3582r

Methanol injection

Bosch 044

And other supporting mods.

Thanks in advance, would be happy to listen to any ideas about this. I should emphasize that I am very much willing to learn and already doing so for couple of months about the EFI, but did not learn at all about the wiring, which i will do very soon. I hope the courses here would help me to achieve my ultimate goal.

Shame you fell out, sometimes it is communication, sometimes tuner, sometimes client - but then words are spoken and...

Did you say what ECU you are currently using?

One advantage of Europe is it is relatively easy to get around for some of us 4-500km drives are nothing special but that can get you to a dozen or more countries and that means you have a bigger selection of possible tuners, might be worth checking out what is fairly close to you, their reputations and other Audi owners thoughts on them, then using the ECU they have most experience and confidence with.

There are numerous 5 cylinder builds around, have a good look at exactly what they are doing and if they mention any problems - for example, you mention using methanol, that suggests a desire for serious power, so pistons, connecting rods and head gasket sealing will need to be addressed.

Not too familiar with those engines, but even the stock engine has some known problems, like the rear chain failing (if it is the late model engine), so don't forget the basics.

Thanks for reply Gord,

Indeed some serious power is expected. The internals are all forged and as i've mentioned the supporting mods are there as well.

Currently I'm using Invent ECU, it's not a well known brand globally, mostly used in the east Europe though. Indeed about 4-500km, across the border (in Romania), there are people using EMU successfully for many years, so I guess I could talk to them.

The 5 cyl I am using are quite reliable tbh, it's the AAN engine (originally 2.2t), but I'm using a diesel block 2.5 and the 2.2 AAN head :).

What year is your vehicle? Are all the body functions (gauge cluster, HVAC etc) controlled by CAN message? If so do you care about that stuff working?

1992, everything is working fine. I'm not sure yet if this is communicated through the CAN input, will do my research soon. Thanks

Hi Vlad4MD :)

Good to see some other 4 ring fan :)

I have a 1990 coupe quattro with a 20vt swap and a 1993 S2 - both 5cyl 20v turbo ABY so very similar to your AAN.

You don't need to worry about CAN. The biggest issue on the Audi 5cyl is the unique trigger system - you need to consider whether your standalone has an appropriate trigger decoder or move to a 60-2 trigger using an aftermarket flywheel or you can use the 60-2 rear crank seal trigger from the Lupo.

Have you considered Maxx ECU? they have a plug-in adapter for the Audi 5cyl wiring harness and it is a well supported platform in Europe. Maxxtune also have a base map for the Audi 5 cyl using the standard trigger system, and I can help you with a MaxxECU base map for a 2.5 stoker also :)

Hello Alex,

Good to see one more 5 cylinder fan :)

Basically, I've got an EMU Black laying around and waiting for its install. Got a base map for the AAN too.

Maybe we can talk on facebook?


A good ECU for an even better price are the MegaSquirt line. Cheapest standalone Ive researched, but top notch quality and history. They've been around for a while and have great customer service. There are also forums there to help if you're the DIY type of guy. They have ECUs that you assemble if your proficient with electronics, or buy one of their preassembled ones. Did I mention the cheap price? Lol

Im running the MicroSquirt ecu in parallel with the stock ECU since my build isnt too crazy (yet). Its a mk4 VW Golf 2.0 8v that I recently turbocharged (T3/T4 turbo) on the stock fuel/ignition system (slightly bigger injectors), for now. Everyone swaps in the 1.8t or VR6 engines and dont bother with the 2.slow, so there are very limited aftermarket support in going quicker/faster.

With just a few emails, they helped me pick the right ecu & additional sensors needed. Some of the stock sensors can be used with the ECU, so you only need to buy a few depending on your car/engine. They're very helpful and knowledgable. Theres also a huge community (atleast here in the states) that help each other out. For the MicroSquirt ECU, MAP & IAT sensor, coolant temp sensor, 8' harness, and tuning software, I paid $550. Pretty amazing for a basic standlone ECU setup.