So, I've decided that I'm going to increase the power output of the mighty 1.4 litre TFSI engine, that lurks under the bonnet of my 2014 Audi A3 Sportback. To that end I have purchased a, so called, piggy-back tuning box made by leading German company: RaceChip.
The box I have here is their top of the range offering, the GTS. It promises up to 24 more horsepower and an extra 60 nm or torque. That is quite a claim, considering the engine is rated at 122 hp and 200 nm in stock form. A 20 and 30 per cent increase for those numbers.
This one is used, I bought it on E-bay for only £75 + shipping, which may be a sign of things to come as a brand new one is almost £400.
Opinions on tuning boxes vary widely; most people seem to agree that there are some gains to be had, but nowhere near the numbers advertised by the people making them. For the £75 I paid for mine, I’m willing to experiment.
So let’s see what this thing actually is.
It’s basically a little black box, with some electronics inside, that acts as an intermediary between certain sensors on the engine and the ECU. In this case the sensors are the boost pressure sensor and the MAP or manifold absolute pressure sensor.
As a digital middle-man, the Machiavellian black box, controls and manipulates the information going to the decision maker ECU in an attempt to amass more power. Nothing new under the Sun.
To put it less dramatically, the chip under-reads the boost and manifold pressure values to trick the ECU into compensating with more boost and more fuel to create a bigger bang in the cylinders.
Now, the problem with this approach is that the trickery will only go so far, as the ECU software will only accept sensor values within a certain range. Under-read the boost pressure to much and the ECU will throw a fault code as, for example, it will find it implausible for the engine to need as much fuel at 3000rpm as it would at 5000 and so on.
The box can only work in the headroom left by the manufacturer to compensate for altitude, fuel quality, temperature, wear over time etc.
Before I install it, I’m going to make some predictions and then we’ll find out which ones comes true:
I do believe that it is possible to gain some mid-range torque, how much exactly, will depend on the things we just discussed.
At low rpms, below 1500, it will do absolutely nothing as the whole premise of its function is based on manipulating boost.
There will be no significant gains in terms of maximum horsepower. To make good horsepower numbers you need to gain a good amount of torque at higher rpms. On this engine that’s not really possible for two reasons:
- It has a tiny little turbo that tends to run out of puff at around 4500rpm as it is; the box demanding even more boost from it, that’s just not going to happen.
- The software in the ECU stays the same; you’ve got the same fuel map, the same ignition timing map, the only difference is that the tuning box is spiking the existing map with a bit more boost and fuel.
So the box will not change the overall character of the engine one iota. It will, hopefully, pull better, but the shape of the torque curve will stay identical to stock.
Let’s begin…
Installation is pretty straight forward as long as you follow the guide provided by RaceChip. The guides for the various products and cars are available on their website.
On this particular engine (1.4 TFSI 90KW/122HP) the air filter housing must be partially removed or at least loosened, to gain access to the MAP sensor.
Watch the video below to see how I've done it:
Leave the blanking plug on the wiring harness provided and connect it to the sensors. Ignition must be OFF at all times.
Side 'A' of the wiring harness connects to the boost pressure sensor and side 'B' connects to the MAP sensor.
Re-install your air filter housing, remove the blanking plug and plug in the RaceChip.
Turn the ignition ON, the small LCD on the box should turn on. If you have the app, now is the time to connect it and follow the on-screen instructions, if you don't then start the engine. It should run normally without any warning lights staying on.
Even if you have the app-controlled version the chip is fully functional without it, so you don't have to connect it, if you don't want to or not necessarily at this stage.
More on that, later. Stay tuned for driving impressions and before/after performance tests.