[OffRoadFun]

I decided to increase the power and torque of my Audi Q5 2.0T sometime back.
The stock power is 211HP/350Nm. Although I have never felt car being underpowered for my needs (crossover), still just thought of jacking up the power by few tens of HPs. The 2.0TFSI still used by Audi still has around 370Nm but power is around 260HP implying a lot of boost is possible.

I did a lot of reading/YT videos on ECU re-map vs Tuning boxes. As per my understanding, a Tuning box, in theory at least, provides the same effect as an ECU re-map. (A tuning box manipulates the MAF sensor readings mainly, and by reporting lower values than the actual, fools ECU into believing more boost is needed via turbo and more fuel injection)

Pros identified:
- Easier to install, it's just a connection in MAF sensor cable
- Cheaper (around 15k vs up to 50k for ECU re-map)
- Can be removed easily


After some research, I identified a German company name Racehip (racechip.com) which will ship free across entire Europe. Coincidently, my brother was visiting Romania from India at the same time. So managed to get it to India without the customs hassles. I ordered the "S" version.

Finally got the "box".




The box had a Y-cable connector and the tuning box to process and manipulate the MAF sensor data to be sent to ECU.




The installation instructions were clear and it was easy. Within half an hour I hooked it up and driving. I religiously followed the instructions mentioned in the "German" manual.

Hooked it up and started the engine. It started but a a few arbitrary warnings started to show-up (Check Engine, sometime ESP warnings). The instruction manual mentioned the warnings will initially show up and will disappear over time. Believing I went for a test drive. I felt some power boost at higher RPMs, the car was changing gears at relatively higher RPMs compared to what it used to do.

I waited for a few days and drove around few tens of kms in the hope the warnings will disappear. They did not. I wrote to the customer service. They were very prompt and after asking a few questions regarding correct installation process, asked me a few minor changes in sequence of installing and running the engine, but to no avail. I checked on some other forums and users of the same product mentioned seeing same warnings in their Audis.

Eventually after a few follow ups, I saw EPC (Electronic Power Control) warning one day.



That was scary and annoying. The customer service asked me to try out a few things and continue driving.

They then offered me to send a new harness (not the box). But I was not convinced and it will have to take the route via Indian customs, a pain.

Suddenly, after a couple of weeks, I had this dreaded "Gearbox Malfunction" warning with Reverse being unavailable. (That's another story, it turned out to be Mechatronic failure which I finally got fixed)


It was probably unrelated to tuning box installation but my appetite had died for a power boost. Spent lot of time debugging Gearbox failure. The initial quote to fix that was minimum 3.5L (and was scary) though I ended up getting it fixed for much less finally.

I uninstalled the tuning box since then.



Come April 2022, stars were good and made some unexpected gains so decided to reward myself by going for ECU tune. I have been in touch with Engineering Exponent in Whitefield for some time. They quoted boost to 255HP/410Nm which was impressive, especially the torque. Took the Q5 there and they did the job in 30 minutes.

Took the car for testdrive and the difference was easily felt during driving. Engine was much more responsive and acceleration boost was tangible.

No issues till now, very satisfied.

At least for me, Tuning boxes are a complete waste. It is just lying around with me now. ECU re-map works well.

Also, both Tuning-box/ECU-remap vendors claim fuel efficiency will increase post the boost by up to 10%, I saw no change at all in FE at all (~5.75 kmpl for me, consistently in BLR traffic with heavy foot on pedal).

[AKSarkar1]

Such small tunes and refreshes help keep the car fun even when it begins to cross the 5-7 year mark, this is probably the first time that I have heard of a Q5 being tuned (quite interesting)!

There is a reason why people leave such jobs to the experts, I couldn't dare experiment with my German car's engine but props to you for trying that!

[pooravB]

Can you please explain how does ECU remap works? You mentioned that there was a significant increase in the power and torque output and was even told that the FE will increase by around 10%, but as you said you didn't notice any change in the FE. So what I don't understand is that doesn't higher power figure means that the car will provide even lower FE? How do they manage to keep the FE constant (if not more economical) even after such boost in the power and torque figure?

[Turbanator]

Originally Posted by OffRoadFun

After some research, I identified a German company name Racehip (racechip.com) which will ship free across entire Europe.
Finally got the "box".

At least for me, Tuning boxes are a complete waste. It is just lying around with me now. ECU re-map works well.

I wish you had asked here about RaceChip before buying one. I, too, had a bad experience; in my case, since I got the box from the US, I had a hard time getting an answer. US guys were adamant that this has something to do with the EU variant of my Car and no support from the EU as I had bought from the US (maybe the EU is the main company and the US is the franchise). I got this hooked to my X5, and the engine was behaving very differently after a few days. It turned out to be some rail pressure warning. A friendly dealership at that time cleared the faults, but I had no appetite left, so I got it removed.

My experience with tunes is also so-so, but most others have positive things to say. What I can, however, recommend is a gearbox tune from xHP. It has completely transformed my lazy 740.

[OffRoadFun]

Originally Posted by pooravB

Can you please explain how does ECU remap works? You mentioned that there was a significant increase in the power and torque output and was even told that the FE will increase by around 10%, but as you said you didn't notice any change in the FE. So what I don't understand is that doesn't higher power figure means that the car will provide even lower FE? How do they manage to keep the FE constant (if not more economical) even after such boost in the power and torque figure?

An ECU has a set of "maps" coded into it which, loosely speaking, is given the MAF (Mass Air Flow Sensor) and other settings decides what amount of fuel can be burnt inside the chamber. There is no single correct value, the map is derived by the engine maker depending on various considerations like fuel economy, reliability, emission norms. By re-mapping, the map is changed which almost invariably means increased power and may be increased emissions or getting closer to reliability envelope (but not crossing it as per the vendors). One can theoretically also choose a map to bring down power to increase fuel efficiency of same engine.


The reason the vendors claim the FE might improve is because more power/torque is now available at a lower RPM, meaning lesser gear shifts. Note, it may or may not mean a bit more emissions. And that's why my FE has not changed in city and on highway this time I experimented with cruise control at 85kmph and 100kmph where the Audi's instantaneous fuel consumption numbers showed around 14kmpl and 12.5kmpl respectively which are impressive as I have never gotten FE in double digits till now.

[pooravB]

Originally Posted by OffRoadFun

The reason the vendors claim the FE might improve is because more power/torque is now available at a lower RPM, meaning lesser gear shifts. Note, it may or may not mean a bit more emissions.

So basically due to increase in initial torque the FE increases. Got it. Thanks man. And Audi Q5 doesn't give double digit FE without remap even on highway? Doesn't it have 2 litres engine?

[OffRoadFun]

Originally Posted by pooravB

And Audi Q5 doesn't give double digit FE without remap even on highway? Doesn't it have 2 litres engine?

No it does not, even after remap on any meaningfully long trip yet.

It's a 2L petrol engine, turbocharged so FE is going to be low. As a general rule of thumb for turbocharged petrol engines, a 2L turbo is equivalent to 3L naturally aspirated engine in terms of power and also in FE with marginally more FE in turbocharged engines. Other factors like older engine and heavy foot on pedal bring it down in my case.

[pooravB]

Originally Posted by OffRoadFun

As a general rule of thumb for turbocharged petrol engines, a 2L turbo is equivalent to 3L naturally aspirated engine in terms of power and also in FE with marginally more FE in turbocharged engines.

I had the impression that turbocharged petrol engines while providing power equivalent to bigger NA engines, delivers higher FE, since the combustion of fuel is better with all the extra air being sucked in, thanks to the turbo.