SYSTEM SAFETY AND INTEGRITY
An unwritten law that sets a quality upgrade apart from a cobbled together set of aftermarket parts, includes that all vehicle management systems retain their integrity. By that we mean all the vehicle’s safety systems that were integrated ‘at birth’ (i.e. chassis, engine management and maintenance), must remain in place to look after the vehicle after the upgrade.
These must include ABS, any stability control programmes, anti-skid, traction/torque control, etc. Any changes to the operation of these systems would render the upgrade a ‘downgrade’, and have no place on the commercial market as a road car. This is not the case for track cars that operate under different rules and by different drivers.
ENGINE MANAGEMENT SYSTEMS (ECU/PCM)
This is also important as many aspects of the vehicle’s safety systems rely to a greater or lesser extent on the ECU/PCM for information and/or operation. Many, if not all cars built these days have an incorporated ‘drive by wire’ throttle system. This is regarded by some as an over-complication of a simple process. What is misunderstood is the part this system plays in the overall safety of the vehicle. For instance, traction/torque control/stability controls are all governed to a degree by the ‘drive by wire’ throttle. Just because the driver mashes the pedal to the floor does not necessarily mean that the throttle will open to the same degree. In a millisecond the ECU will calculate the most efficient throttle plate angle for engine speed, car attitude and grip available. Far from being a hindrance to the driver, it must be considered a friend as it’s taking into consideration far more aspects than an average driver is able to assimilate, especially on the way to work in the morning when he or she is thinking about the kids, the troubles at the office and the events of the previous evening, etc! Whilst we humans are thus otherwise occupied, the Engine Management System is keeping a constant watch over the safety of the vehicle.
There are many systems built into the ECU solely for engine protection and emissions. Again, these cannot be compromised. The ‘knock’ and ‘lambda’ sensors play a huge part in how the vehicle drives, the fuel economy and not least engine safety. Any omission or changes to these systems must spell danger to the purchaser and should be avoided.
Of special importance is the open/closed loop lambda system:
For all the extra air being ingested when under boost, it is vital that the Air/Fuel Ratio is maintained to levels that are vital for the safety of the engine. These are under low load ‘closed loop’ conditions (AFR 14.7:1), high load ‘open loop’ (13.2:1 max torque to 12.5:1 max power). Should any irregularity to these be seen by the lambda system, it will bring on an Onboard Diagnostics (OBD) code showing either ‘lean condition’ (can cause detonation). Alternatively ‘condition rich’, which can severely deteriorate the catalytic converter. Should either condition be present an immediate code is shown. It will also identify the offending bank and the associated condition.
The knock sensing capacity of the AMV8 engine is also key to its ability to make timing allowances for lower grade fuel (unlike it’s bigger 12 cylinder brother which cannot change its timing to accommodate such a change). Therefore, this system must also remain completely intact with no interference from an ‘outside party’, namely another ECU, etc.
Here at GMR we take special care to ensure that all of the above are retained. Our systems are integrated to run alongside your car’s existing system and in no way affect the complex monitoring systems in place as set out in the OBD2. Nothing is hidden and should any of the engine systems be outside these parameters then the PCM/ECU will bring up the associated warning, as it would prior to the upgrade.
Normal maintenance procedures and service timings can be adhered to. The only additional requirement is to examine the supercharger belt at service: 24000 miles or 3 years whichever comes first: In addition the supercharger gearbox oil will need changing after 250,000 miles!
Our development car has completed over 77,000 miles in supercharged form (@ early 2016). The clutch has covered 57,000 miles (including many test drives and track sessions) with no detectable deterioration in either feel or travel. This is indicative of the benefit of the conversion, as the car now only has to do half as many gear changes as it used to, due to the greatly increased torque available at low RPM’s in the higher gears. So much less use of high RPM gear changes means that the net result is substantially less shocks and stresses on the drive train as a whole. That said, we are not recommending supercharging your car simply to extend clutch life!