BSR Stage 3 tuning kits are generally developed using BSR Sport Flow exhaust, BSR 3" downpipe with sports catalyst and the rest of the car's components in stock configuration. Some of the Stage 3 tuning kits have another configuration, and the box "Kit comprises" (see below) always shows exactly which components that are upgraded. Using other components than the ones showed in "Kit comprises" will affect power, drivability and durability. In the tuning kits all necessary components are listed that will ensure claimed power levels. Using other components will result in BSR not being able to anticipate the results of the tuning procedure.
Please note! To avoid causing damage to the car, BSR Stage 3 components must only be combined with BSR Stage 3 software. Do not load stock software into the car when the car is equipped with BSR Stage 3 components.

Changing air filter
When changing air filter, make sure that the filter has a filtration level and flow rate suited for the power of the engine. All BSR air filters are qualified accordingly.

Changing exhaust system
Changing the exhaust system (cat-back) will improve performance if the back pressure levels are lower than for stock system. Most modern cat-back systems branded as "sport exhaust" will provide this. As a consequence, feel free to fit a cat-back system in combination with the BSR PPC.

Changing downpipe
Changing the downpipe to a larger diameter version will change the back pressure and as such it should always be combined with proper software. BSR Stage 3 tuning kits are calibrated using BSR 3" downpipes and as a result of this, only BSR's downpipes are to be used for best performance.

Changing BOV (blow off valve)
Stock valves in modern cars are of high quality and function, thus there is no need to change them. Many of the aftermarket BOVs actually offers less performance in comparison. "Open air" BOVs are not to be used in cars with air mass meters, i.e. all cars younger than 10 years. BSR PPC software is calibrated for stock valves only.

Changing catalyst
The term "race catalyst" is sometimes used to describe a catalyst with high flow rates and low back pressure. The majority of these catalysts achieve this by having inadequate catalyst function which affects our environment in a negative way. Furthermore, it also might cause problems with the cars internal diagnostic features. As a consequence, BSR will advice you not to use such a catalyst.

Changing sparkplugs
We recommend you to use stock spark plugs, in particular for Saab engines as they use the plugs for misfire detection. Driving under hard conditions (track days, high speed highway driving), we recommend you to change the plugs at a more frequent rate than what is described in the owner's manual.

Changing intercooler (IC)
In BSR tuning kits where the stock intercooler has been found inadequate, an upgraded version is offered. Since changing the intercooler also requires a re-calibration of the software, such a change is only possible for cars that have an intercooler in the tuning kit.