Plug 'n' play chip tuning boxes are big business these days, with a plethora of companies, like RaceChip, specialising solely in their sale. To differentiate themselves, each company offers slightly different packages, each with it's own USP.

For the customer, this one-up-man-ship can be quite confusing.

If you're only interested in which tuning box is best, scroll on down to the bottom for my recommendations.





What is a Chip Tuning Box?


Let's rewind for a second and talk about what exactly a tuning box is. A chip tuning box, sometimes referred to as a piggy back tune or piggy back ECU, is added in between one or more of the car's sensors and the ECU (Engine Control Unit). The tuning box intercepts the signals it receives from the sensors, modifies them, then sends them on to the ECU. These modified signals trick the ECU, allowing the tuning box to control boost, fueling, timing and ultimately performance.



Remap vs Chip Tuning Box


It's probably about this point that the purists will pipe up saying that you should avoid tuning boxes altogether and get your car professionally remapped. I absolutely agree, if you're serious about performance tuning, there is no substitute for a bespoke remap, tailored to your individual car's characteristics/modifications.

That said, tuning boxes definitely have their place. They are quick and easy to install (and remove), are usually untraceable when returning a car to the dealership (i.e. doesn't void your warranty by triggering a TD1 flag) and offer serious bang for your buck (within spitting distance of a remap). Unlike a remap, tuning boxes can be removed and re-purposed for your next car, RaceChip and TMC Motorsport both offer a reprogramming service which, when combined with a new wiring loom, will fit right into your new car.

Not all tuning chips are created equal though, a £20 eBay special claiming to offer 100bhp gain is definitely too good to be true. You must also ensure the tuning box is specific to your vehicle (not a generic one chip covers all variants).


Audi S5 3.0 TFSI Tuning Box Options


Without further adieu, here's the list of the top tuning chips for the Audi S5 V6 3.0 TFSI that I'm going to be comparing. I'm not just comparing them for the sake of it either, I'll be putting my money where my mouth is and buying the one that comes out top!


The best chip tuning box is going to mean different things to different people, some people will want the most power gain regardless of cost, some will want the best bang for buck. The table below will help you drill down into the detail and decide which is best for you (click it to enlarge for extra clarity).

Audi S5 Sportback 3.0 TFSI V6 chip tuning box piggy back ECU comparison

Most of the tuning chips on offer provide a similar performance gain. According to Audi, the B8 S5 3.0 TFSI V6 came out the factory packing 333PS and 440Nm of torque, which means these chips are going to boost performance by roughly 15-20%.





Which Chip Tuning Box Is The Best?


The ludicrously priced MTM M-Cantronic 317kW, however, increases power output by an impressive 30%. At the eye wateringly high price point of £2,275.62 (€2,491.24) though, you'd have to be utterly certifiable to consider it as an option. That said, MTM's other offering, the 280kW tuning box, is an even worse proposition if you compare the price per PS increase, by far the most expensive option in the comparison. To put it into perspective, for a shade under £1500, you could roll your car into Revo's workshop and put your feet up whilst they upgrade your supercharger pulley, induction kit and do a Stage 1+ remap...

In stark contrast to the MTM boxes, the TDI-Tuning CRTD4 offers incredible value for money, increases to both power and torque costing just under £6 per PS/Nm respectively. This is without doubt the best bang for your buck option available for the S5. It even comes with a class leading warranty of 3 years and a money back guarantee period of 30 days. For most people, particularly those modifying on a budget, the CRTD4 is the chip for you.

TDI-Tuning CRTD4 Tuning Graph

TDI-Tuning CRTD4 Chip Tuning Box Audi S5 3.0 TFSI V6 Dyno Graph

However, the best for me means best value for money, not necessarily the biggest gains, but a solid mix of low cost per PS/Nm increase and the most feature rich. TDI-Tuning, TMC Motorsport and to a certain extent RaceChip were all in the same ball park.

Costing over £100 more than the TDI and TMC options, I'm going to rule out the RaceChip Ultimate. The website doesn't mention any warranty nor does it offer a mobile app for the S5 (although it does for other cars at an additional cost of £50). I spoke with RaceChip customer service who confirmed there is no timing on when, or even if, the app will be made available for the S5.

And then there were two... TDI and TMC provide their performance increase in two slightly different ways, the TDI is a more balanced increase of power and torque, whereas the TMC chip is more torque biased. I doubt in reality you'd be able to tell the difference between the two, although the bragging rights of hitting 400PS might tip the balance towards the TDI's chip though.

However, it's the mobile app (available on both Android and iOS) that really sets the TMC option apart (the screen grabs below are in German, but the app is in English in the UK).

TMC Motorsport Tuning Box Android App Home Mode Select ScreenTMC Motorsport Tuning Box Android App RPM Screen

The app connects to the tuning box via Bluetooth, and has a number of features like live RPM readout and the ability to switch between off, Eco, Sport and Sport Plus. It's the 'Cold Start' feature though, that I think is most useful. It allows you to set how many minutes before your chosen mode is activated, giving your car chance to get up to a safe running temperature before turning the performance up to 11. Does that make it worth near enough £63 more than the TDI? For me, absolutely. Ok, it is a bit of a gimmick, but who doesn't like showing off in front of your mates?

A solid price per PS / Nm increase, combined with the app, warranty and money back guarantee makes the TMC Motorsport tuning box the best value for money option in my eyes. I'll be taking my own recommendation and placing my order in the next few days. Stay tuned to the blog for plenty more tuning box content to come, from fitting guides to performance testing!


Conclusion




Let me know what you think in the comments below, are there any tuning box options I've missed? Which one did you go for? Are you happy with it? Has anyone proven these chips on a dyno?

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