The Control Unit
The Mobile Phone app
Is installed on any Android mobile phone running Android 4.2 or higher. It can take screenshots of significant events and can spray water in the intercooler
The mobile phone app communicates with the monitoring unit and is updated with the latest data once every second. A time-stamped and serially numbered screenshot can be captured to record interesting events for later analysis. The app will allow a photograph to be taken after every screenshot so that the location of the event or current instrument-cluster conditionscan be recorded.
The Installation page provides details of the minimum mobile phone requirements and how to install the app.
The Turbo Diesel Engine
The output power of a diesel engine may be enhanced by raising the the density of the induced air above ambient.
Increasing the density of that air is a two-stage process: first the pressure (and temperature) of the incoming air is raised in the turbocharger, and then the density of the compressed air is increased in the intercooler reducing the air's temperature to as near as possible that of the ambient air. If no cooling takes place then the density will not be increased and the power of the engine will remain unchanged. The cooling process begins within the turbocharger and continues through all the ducting including the inlet manifold - the intercooler removes most, but not all, of the heat energy from the induction airflow.
Mathematically this is shown by the Ideal Gas Law PV = nRT; where V and R can be disregarded since they remain constant. The density n will only be increased proportionally to the pressure P if the temperature T remains constant. If T changes with P then the density n remains unchanged.
Should the temperature of the induced aiir be cooled to match the ambient air then the efficiency of the intercooler is 100%, if no cooling takes place the efficiency is zero.
A turbocharger may elevate the induced air pressure by as much as 1bar or 100 KPa. At sea level this means doubling the ambient pressure and, in doing so, doubling the ambient temperature as measured in Kelvin. The Kelvin scale matches the Centigrade scale except that zero Kelvin is equivalent to -273 degrees Centigrade. It follows that ambient air at 20 Centigrade will be 293 Kelvin, and doubling that to 586 Kelvin is brought back
back to 313 degrees Centigrade.
The intercooler cools induced air by transferring its heat energy to the outside cooling ambient airflow which, in the case of top-mounted intercoolers, relies upon forward motion of the vehicle to elevate pressure at the mouth of the bonnet-mounted air scoop. Without that forward motion the temperature of the intercooler will quickly rise, rendering the entire system ineffective.
None of the above applies to petrol engines since the boost ratio is far lower and fuel evaporation causes substantial cooling of the intake air.
If rthe towing of a trailer increases the tow vehicle's fuel consumption then it stands to reason that the extra air required to burn the higher fuel quantity must pass through, and be cooled by, the intercooler, and the added load will result in warmer induction air being delivered to the engine. How much hotter this air will be depends on many factors, some of which are hard to predict, so the practical outcome is best measured empirically under real highway operating conditions.
Live testing has shown that a 10% - 20% loss of intercooler efficiency can be expected while towing a medium-sized (1000kg) trailer. On a flat road at highway speed the induction air temperature will rise from about 20 degrees C above ambient to around 60 degrees above. During hard 3rd gear climbs the induction air temperature may reach 100 degrees C above ambient.
The standard Intercooler as designed by the motor manufacturer are generally well capable of fulfilling their intended function, and it is difficult to make a convincing case for enhancing their capacity or performance. This does not apply to towing trailers however where arduous conditions can overload an intercooler and result in a loss of up to 15% of total potential engine power. Increasing intercooler capacity might lead to a recovery of much of this power loss.
What the Analyser Does
What Benefits You Can Expect.
Any standard factory fitted intercooler will deliver between 80% and 90% efficiency under highway cruise conditions, which means the induction air will be cooled to within between 30 and 60 degrees centigrade of ambient. Since this represents a loss of potential engine power of only 5 - 10% it is difficult to justify an expensive after-market intercooler, which itself will never be more than 90% efficient since enthalpy slows markedly as the temperature gradient across the intercooler reduces. The last 30 degrees of heat is the most difficult to lose.
However what will be interesting to learn is:
An average-sized turbocharged engine at full power sucks upwards of 100 litres of air every second. All of that air must pass through minute holes in a paper screen that may not be larger than 5 microns in diameter. Any clogging of those holes will impede airflow and cause a partial vacuum between the filter and the turbocharger. With a clean air filter that pressure drop won't exceed 20mB, but will increase rapidly as available holes in the filter become clogged with dust particles. We can accurately measure that drop in pressure.
Turbochargers require large volumes of exhaust gas to drive the turbine of a turbocharger hard enough to develop 1 bar of boost pressure. This volume of gas cannot be generated unless the engine is working at large throttle openings under load.- which requires highway driving conditions. Excessive boost is prevented by an exhaust gas waste gate opening as the turbocharger approaches maximum boost. The operation of the waste gate can only be tested under full load conditions.
Under highway driving conditions the air pressure under the bonnet will be very close to ambient. At 120Km/h the ram effect at the intake of the scoop above the intercooler will be 555 Pascal or 5.55mB above ambient, which is sufficient pressure differential to send a strong airflow through the intercooler's vanes. During an arduous climb at 60km/h with the engine's cooling fan working hard, this pressure differential can be much reduced, slowing this airflow considerably - even reversing it at times, when hot air from the radiator flows upwards through the intercooler elevating induction air temperatures to as high as 150 degrees Centigrade and degrading intercooler efficiency to 50% and causing an effective loss of 25% of potential engine power.
Collectively these conditions can rob the engine of a considerable portion of its potential power, and they can be comparatively inexpensive to remedy.
Much is made of the fact that race cars are equipped with jets that can spray cooling water onto the outside of a intercooler to enhance it's operation. Spraying water onto an intercooler can reduce it's temperature by up to 20 degrees C for a short period during which any performance increase from the engine can be assessed, but it does not remedy any long-term problem.
The controller can deliver 12V output power, through a relay controlled from the mobile phone app, to an external water spray pump, to simulate the effects of improved intercooler efficiency. The spray pump is typically an after-market window-washer pump that must be separately installed.
It is easy to imagine vast amounts of air being forced down the throat of a forward-facing snorkel and greatly augmenting the engine's output power. In fact, as can be seen above, the ram effect at the mouth of the snorkel will be only 5.5mB at 120Km/h. Compare this to the partial vacuum of up ten times that figure that may exist between the air filter and the turbocharger if the filter is even slightly dirty, to put this in perspective. A forward-facing snorkel will make no significant improvement to an engine's output power, though it may confer other important benefits.