BSR's Tuning Goals
Modifying a vehicles ECU software or output signals for more 'peak power' is relatively easy and is the focus of the much of the tuning industry. Many producers and consumers, compare products using this factor alone. BSR is concerned with more than power. We create products with 3 goals in mind;
Smooth Power -
Vehicles with a spike of high rev power, but little on offer down low may make great drag cars, but they are tiresome as road cars. With every-day driver enjoyment in mind, BSR's increased power and torque is delivered smoothly across across the rev range. While we do measure and publish peak power, we also display graphed results and power gains expressed as a percentage, across the rev range.
Economy (via Efficiency) -
Power and economy appear at first to be opposing goals, however it is how efficiently power is produced and how it is used by the driver that determine economy. Consider two identical cars in two different states of tune. The first makes optimal use of the energy contained in the fuel, it is efficient and powerful. The second, in a 'detuned' state, has different boost, ignition and fuel settings, slightly more fuel passes through unburned, it's less efficient and less powerful. In a test of economy, the 'optimal' car closely follows the 'detuned' car 100kms from A to B staying say, 25m behind it at all times. Forced to drive at the same pace, the optimised car will use significantly less fuel. This example shows how an efficiently tuned powerful vehicle may also be more economical, depending upon how it is driven. BSR tunes for efficiency, from there fuel economy is up to the driver.
BSR's over-riding goal is to maintain reliability. Long term reliability is never sacrificed for gains in efficiency or power. As can be seen below, much of the time our engineers spend developing tuning for a vehicle goes into identifying its weakest link. Rather than figuring out where power gains can be made, the engineers first job is to determine the levels that they must not later exceeded.
Achieving these 3 goals is a far more difficult task than that of maximizing peak power alone. It is one that requires the right equipment, rigorous testing, development, skill and experience. The following is a summery of the procedure applied to every model of vehicle for which BSR has developed a tuning solution. 1. Study of engine and transmission design and characteristics
At the beginning of every project we study the engine and transmission characteristics of the vehicle. This stage includes a thorough investigation of the cars fundmental features and properties, identifying any items that prevent or restrict tuning. Based on theoretical calculations in combination with practical tests, as well as previous experiences from earlier versions of an engine, a basic set of guidelines are produced regarding the cars suitability for an increase in power. Second, the car manufacturers choice of fuel injectors, turbo charger, fuel pumps etc. are analyzed in order to determine what power levels it is possible to reach.
For each transmission setup, BSR takes into consideration the properties of that particular transmission type as modern transmissions have sophisticated software diagnostics and control features. This is something that needs special attention for durability and comfort purposes. When a conversion kit is about to be developed for alternative fuel usage such as E85, the study is extended with material analysis of each component that comes in contact with the new fuel type to fully understand what results can be expected.
2. Analysis of engine and transmission parameters during operation
A complete analysis of all engine and transmission parameters that will be affected during a tuning operation are carefully performed under load. This part of the development is performed on a chassis dynamometer as well as during extensive test drives under varying driving conditions. All parameters are logged and analyzed; exhaust gas temperatures, oil temperatures, manifold air temperatures, back pressure characteristics as well as the performance of each engine part. It is of utmost importance that the test cell used during the evaluation has all the necessary hardware and software features required to simulate all possible driving conditions. At BSR, state of the art equipment as well as world class software is used for this.
All fuel types used by modern combustion engines are based on three major components. Carbon (C), Hydrogen (H) and Oxygen. These three components occur in different proportions depending upon the fuel. For standard petrol and diesel fuel, the oxygen level is negligible and the oxygen is added via the filtered air intake . For alcohol based fuels (such as ethanol that is commonly used as additives) oxygen is present. A generic description of the combustion phase is:
Oxygen + Hydrocarbon => Carbon dioxide + Water
With just the right mixture and ideal combustion no oxygen remains and the combustion is labeled 'stoichiometric'. Commonly, the Greek letter lambda (λ) is used to describe this where λ=1.0 implies a stoichiometric combustion. It also describes any oxygen surplus e.g. a 10% surplus would be λ = 1.1. This measured value is very important whilst calibrating the fuel settings of an engine as it gives a direct feedback on the properties of the fuel mixture during engine operation. In real life, the combustion is seldom perfect as residue chemical compounds are always present such as hydrocarbons, carbon monoxide, oxygen and nitrogen oxides. These are carefully monitored by the engine vendor and during the development phase at BSR, actions are taken to maintain or decrease stock levels. As such all BSR tuned vehicles meet or exceed strict European emission standards.
One important aspect during this part of the evaluation is to understand that low fuel consumption and good mileage do not automatically mean low emissions. When running an engine lean (less fuel, more air) the temperature in the combustion chamber increases, creating toxic nitrogen oxides. At a glance, the car will show improved fuel economy, but a deeper analysis will reveal toxic exhaust fumes as well as increased thermal strain on the engine that in time will affect it's durability. The term "ECO-tuning" is often used, but this type of tuning can have very negative side effects. When developing BSR conversion kits, a thorough investigation of the emissions is performed for all the fuel types and mixtures that will be used.4. Recommended operating ranges and absolute maximum ratings
The results from the analysis of engine and transmission parameters during operation gives an understanding of what power levels the engine and drive-train can handle. Each engine component is designed to work within a certain range and, by mapping this range for all components using stock software, a matrix showing how fit each component is for wider use is produced. BSR never overrides the component manufacturers recommendations for operating range and in cases where a component is at risk of operating outside its range, it is replaced with a correctly sized unit. This can be seen in tuning kits where turbochargers, fuel injectors, intercoolers or exhaust systems are upgraded.
5. Functionality of engine management system
Next step in the development phase is to chart the engine management system and to explore avenues for tuning. This phase of the development is very time consuming as a modern engine management systems have a myriad of features and functions, each playing a role in the engine's reliability, drivability, performance, fuel consumption and exhaust emissions.
6. Safety features
An optimized calibration of the engine management system is very important in order to
ensure that all safety features such as spin control and ESP (Electronic Stability Program)
are still fully operational after the tuning of the engine. Also, the anti theft features of
the vehicle must not be affected by tuning, all diagnostics, service and maintenance
routines must remain operational to ensure that the car will receive proper care when
serviced. For cars with automatic transmissions, all safety features are maintained e.g.
torque control during gear shifts. 7. Calibration of management system devices
After having charted the engine management system the re-calibration phase begins and the power and torque is increased while keeping all engine components inside the manufacturers recommendations. During this phase, all engine parameters are measured and logged as tests are taking place both on our chassis dynamometers and road tests. The latter also includes subjective impressions such as driving experience, throttle response and engine behavior. In order to optimize both drivability and comfort, the engine management system is, where applicable, calibrated with individual torque levels in different gears to obtain maximum performance and driving experience without unnecessary wheel spin.
8. Secondary analysis of engine & transmission parameters during operation
As soon as the re-calibration of the engine management system is completed, the analysis of the engine performed in stage 3 is performed again. This is to ensure that no engine component works outside its recommended range. This analysis is performed both on the chassis dynamometer as well as road tests with all engine data logged and analyzed. 9. Characterization
Once all engine parameters are analyzed in operation and any minor corrections to the calibration are complete, the characterization begins. During this phase, the engine performance is measured using a Rototest VPA chassis dynamometer. Also, emissions tests are carried out as well as accelerations test in several gears and speeds.
The qualification procedure requires that several cars are subjected to long term testing when being driven under various conditions and loads using different driving styles. All test results are monitored, logged and evaluated.
11. Programming tools
During this phase, tools for programming customer cars are developed. The majority of the cars are programmed using BSR's PPC2 and PPC3 devices, but serial communication using a computer is required in some cases.
Models from most car manufacturers undergo several revisions over their lifetime and manufacturers frequently provide updated software packages for their vehicles. These packages are analyzed by BSR incorporated into the BSR tuned files and offered to our customers as the manufacturer distributes them.