Master and slave: the differences

When it comes to engine tuning, we often talk about two types of user: master and slave.

When choosing a new reading and flashing interface, the question of master or slave usually comes up. It is crucial to choose the interface that best suits your practice, skills, volume and budget. This article outlines the advantages and disadvantages of each to help you make the right choice.

Which one do you need?

1. You have been trained to modify files with editing software such as WinOLS, Swiftec, Stage X, ECM Titanium, etc.: you need a master tool.
2. You don't know how to modify files yourself and want to leave that to experienced tuners:
   1. You still want to work with several providers: you need a master tool.
   2. You know you will be working with one trustworthy provider and are confident you won't need any other partner: you need a slave tool.

BOBPerformance welcomes slave users with an Alientech KESS3 tool linked to our master account (we supply KESS3 slaves).

The slave interface

By definition, a slave user is always connected to a master. The files read by a slave user can only be decrypted by the master they are linked to.

The files sent back are also encrypted and cannot be opened or modified by another master user. A slave file is unique and cannot be reused on another vehicle.

Working as a slave with BOBPerformance offers considerable advantages:

• Files are 20% cheaper.
• Free retuning if a vehicle has been updated.
• Free return of a vehicle to its original state.
• Stage evolution possible, with only the additional options charged.
• More extensive support in case of problems, with explanations on how to proceed.

Refunds for slave users

The refund policy is also different. If a slave user has trouble writing the program to a vehicle and can show that the necessary steps have been taken (e.g. opening a support ticket), but the program cannot be written to the vehicle's ECU for obvious technical reasons, we may refund the credits used.

A financial refund never applies: we are talking about credits on the BOBPerformance account.

If a slave customer does not download the file because they realise the vehicle they are working on is not in good enough condition to be tuned, we can cancel the request and adjust the credit balance in their favour.

The master interface

Working as a master means the user receives an open file. The master user can then reuse and modify this file as they wish or according to their customers' requests.

The customer owns the file and can therefore use and reuse it at will, without any control on our part. A master can also choose to buy a file purely for information, observation or to analyse a solution.

Refunds for master users

The refund policy is not at all the same for a slave user and a master user. For a master, we provide a service with no obligation of results.

A master user is expected to know how to open, modify and copy a file. If they buy a solution from us and apply it to a vehicle that has a potential failure or is in poor condition (fuel, ignition, etc.), no refund will apply.

We primarily sell a calibration, but it is always possible to fine-tune the file for a particular case or if there are issues related to the file provided.

Invoicing for master users

For a master user, every request is charged. Whereas a slave user only pays for the additional option in the case of a stage evolution, a master must pay for the entire request again.

To put this into context, here is a concrete example:

• File 1 for vehicle X: stage 1 + Vmax OFF option.
• File 2 for vehicle X: stage 1 + Vmax OFF option and Launch Control option.

The slave customer will be charged for all of file 1 and only for the Launch Control option on file 2. The master customer will be charged for all of file 1 and will also have to pay again for all of file 2.

If they start from the existing file, they can buy only the additional options but will pay a base stage fee. If the master customer wants stage 1, the Vmax OFF option and the Launch Control option separately, this is possible but requires 3 separate, fully charged requests.

The reason is that we assume a master user can classify these files, export them, combine them and reuse them as they wish.

If the vehicle software is updated at a dealership, the new file provided by BOBPerformance will be charged: the software version is different, so it is a new file billed at the initial rate.

Finally, BOBPerformance's responsibility towards a master user ends once the file has been provided. If the master fails to flash the calibration to the vehicle (e.g. an issue with the reading interface), no refund will apply, because the file provided can be reused in the future.