Remap Vs Tuning Box

Boot tuning remap and Tuning box

What is remap, and what is a tuning box


A remap is a modification to the cars factory ECU (engine control unit) by which the values of the engine mapping are changed at various points to improve power and/or fuel economy. A good remap is carried out on a rolling road, where the remapper uses a computer to reprogram your ECU with new software.


Tuning Box

A tuning box is a physical piece of hardware that provides very similar modifications to the cars mapping values, however instead of modifying the vehicles ECU software, this is left alone and the tuning box plugs into the cars wiring loom. This enables the tuning box to modify the signals from the ECU in real time meaning that if the tuning box were to be removed, the vehicle returns back to standard.


What is the set up process?

Many cars can be remapped by connecting a computer and the cars OBD port and copying a mapping file across to the ECU. There are also many cars that require the ECU to be removed from the vehicle and mapped in a workshop. This involves opening the ecu and connecting a computer using probes linked directly to the circuit board. This is often referred to as bench tuning. Remaps should be carried out by a trained technician and is not a DIY solution.

The video below shows a typical bench remap - 

A tuning box is installed by connecting the unit to sensors in your engine bay. Depending on the type of engine and the tuning box is use, these sensors can include common rail fuel pressure, boost, CAM and MAP sensors. Tuning boxes should be supplied with OEM connectors and offer a simple plug and play install. On most vehicles, tuning boxes are a simple DIY solution and installation is often completed in under 15 minutes.

We have a range of installation videos on our YouTube page, the video below shows a typical install to a Mini B38 engine - 


Are there any risks with the setup?

Mapping an engine via the OBD port carries very little risk of physical damage, the biggest risk is the file that is being programmed. Many mobile mappers who use this method, often purchase generic map files from internet suppliers. If the file is not suitable for your engine, you could see performance and reliability issues.

Bench tuning carries the same risks as OBD tuning but also has a risk of physical damage. ECU’s are not intended to be opened and so to access the circuit board, (as shown in the video linked above) ECU’s need to be prised open or even drilled into. Not only does this risk damaging the internal components but any signs of damage or tampering with your ECU will 100% void any warranty on the vehicle.

Another risk to remapping is manufacturer software updates. It is quote common that manufacturers will release software updates. An update is applied by flashing the ECU with the latest software files, this will overwrite any remap and return the engine to stock mapping.

There are 3 simple steps to installing a tuning box. Turn off your engine and let the ECU power down, connect the tuning box to the specified sensors and secure the tuning box, routing the cable away from any moving parts or parts that may get excessively hot, such as the EGR pipe.

If you disconnect a sensor whilst your ECU is powered up, you may get an engine management light on your dashboard. This error will clear on it’s own after a few warm up and cool down cycles or can be removed with a fault code reader.
The only other risk is the potential to damage a connector, it’s rare that this happens but we do advise users to use the harness supplied with your box to familiarise yourself with the connectors and how the locking tabs engage.


What if I change my mind?

A remap is a permanent modification of your ECU, it’s permanent in the sense that the user is unable to put the car back to stock mapping. In order to have your factory mapping restored, you would need to schedule another appointment with the mapper. The risk then, is if you are actually getting the correct map put back onto your engine.

The labour involved in bench tuning your ECU will often mean further charges to have your engine put back to stock.

A tuning box tunes the engine by using live signals from the applicable sensors and will tune the car as long as the tuning box is installed. That means that if you decide to return your car to stock mapping, you simply remove the box from your engine, or with out boxes, simply replace the tuning box with the provided bypass plug.


So which is better?

Customers often ask us why they should pick a tuning box over a remap or vice versa: we would like to give you the unbiased facts so you can make an informed decision. The most important point to make is: not all diesel tuning boxes are the same. Similarly not all remaps are the same. Which one is right for you is entirely dependant on your personal requirements.

Both high quality diesel tuning boxes and high quality remaps can give very good results, improving power and toruqe, reducing turbo lag and improving fuel economy (MPG).

Unfortunately there are many companies out there which offer poor quality remaps and possibly even more companies which offer poor quality diesel tuning boxes, both of which offer a combination of poor performance and potential for damage to your vehicle.

Here at Bluespark Automotive we are prepared to put our money where our mouth is, offering a 28 day no quibble money back guarantee, as well as a 2 year warranty on all Bluespark products.


Presuming that you are comparing products of similar quality, our comparison is as


  • Must be carried out in an area local to the remapper. Not only does this mean that it’s often a long drive to have your car remapped, it also means that you may have to travel some distance if any problems crop up.
  • Remaps are a permanent install, and cannot be removed when you sell the vehicle or if you wish to remove it during servicing.
  • Remaps are not user adjustable and cannot be switched off.
  • Are often removed by the manufacturer when servicing.
  • High quality remaps often cost over £400.
Bluespark Pro Tuning Box
  • Can be delivered in the post and fitted easily by the customer, with full and comprehensive instructions to assist you with the process. If you decide that you are not 100% happy, return the unit to us within 28 days for a full refund.
  • Can be removed when the vehicle is sold, and either fitted to a replacement vehicle of the same model, or sent back to us to be remapped for a new vehicle.
  • The Bluespark Pro Diesel Tuning box is user adjustable, not only for power output but based upon optimisation for your vehicle’s use. For example if you permit an inexperienced driver, maybe a son or daughter or employee to drive your vehicle, power output can be reduced at the turn of a switch.
  • You can also change fuelling if you modify your vehicle at a later date, such as fitting a performance air filter etc.
  • The Bluespark Pro Tuning box is available for the majority of common rail vehicles for £200 and with integrated Turbocharger boost control for £280.