ECU Tuning / Remapping

Turbo Charging Modifications (Stage 1)

Nearly all modern diesel engines have a turbocharger, some even have twin, tri or quad turbochargers. The idea of a turbocharger is to increase the power per engine cycle by improving the density of intake air. The turbocharger compresses the air so that it enters the intake manifold at a greater pressure. The amount of air forced into the engine is referred to as boost pressure. Engine strength and knocking (extreme combustion) limit what can be achieved by turbo boost. However, stock (out of the factory settings) boost pressure is normally heavily restricted so there’s plenty of scope for some improvement on this front.

Boost pressure can be adjusted by changing the settings on the bypass valve for the amount of exhaust gases passing through the turbocharger. The valve is opened when the programmed boost level is reached, allowing the exhaust gases to flow without going through the turbocharger preventing further rising boost. Most turbochargers have an actuator valve, whereas higher power or uprated units often have a wastegate valve. When the amount of forced air is increased, the explosive force is increased, increasing engine output.

Increasing Boost from a Turbo sounds simple. But there are a number of issues

• Overboost - What effect will overboosting the turbo have on the turbo and the other systems like intercooler
• EGT - If the injection tables have been modified, will it cook the turbo?
• Turbo Compressor Chart - It is vital the turbo compressor chart is examined, that way we know how much boost the turbo can make based on the displacment of the engine and RPM. There is no point setting the turbo to boost to a level if it cannot ever get to that level
• Is the Intercooler big enough? If it isn't then charge temps will be too high and you might get pre ignition when you really don't want it
• Will more boost create more lag? Yer the dyno might say you have more power, but will that mean it is faster in the real world?
• Can the charge pipes take an increase in pressure?

Turbo Charging Modifications (Stage 2)

When you want more power you need more air. Seen black some from a disel after a tune? It is caused by not enough air. Quite simply they need a larger turbo. Too much black smoke is going to reduce engine life as it will increase EGT temps and of course that will result in melted pistons at some point.

• Hybrid Turbos - I.e. where you modify an exisiting turbo with parts from another turbo
• Larger Turbos - As you can imagine it will increase boost
• Larger Intercoolers - The charge temps must be kept low
• Ait to Water Intercoolers - Reduce Lag and Improve Cooling. There is a reason it's used in all the highest power cars
• Water / Meth Injection - Works as anti knock tool and also helps reduce temps
• NOS - Well if you need more O2, sometimes a turbo isn't enough

Fuel Managment Modifcations (Stage 1)

Fuel management will also be adjusted during diesel tuning. There is a perfect air to fuel ratio to be achieved.

Fuel management controls the injectors so that the right amount of fuel is injected for the amount of air present. The ECU uses data from the mass air flow meter and O2 sensors to calculate and compare data in line with the stored programming.

By using live data on the rolling road with an air fuel gauge and data logger we can record various parameters under the adjusted boost conditions to create the necessary fuelling adjustments for a perfect balance and optimal performance.

With a diesel the fuel is injected near the end of the compression stroke (when the air is greatly compressed) leading to a short lag before combustion starts which means that there is fuel in the chamber that will ignite prior to the combustion. This causes that distinctive diesel knock and clatter which is more or less unavoidable. Diesel knock is not due to unstable combustion like petrol engines and is to be expected although great efforts are made to minimise the noise.

The most common things we modify when altering the fueling maps are:-

• Rail Fuel Pressure
• Injection Duration
• Start of Injection

Fuel Managment Modifcations (Stage 2 and 3)

Typical modifications for any Stage 2 or 3 Recalibration would possible include:-

• Bigger Injectors or Bigger Nozzles
• Larger More powerful HP fuel pump
• Modificated Fuel Rail Sensor to ensure it can manage higher fuel pressure levels
• Possible dual fuel pump and dual fuel rails
• Improved Fuel Cooling

Other Map Modifcations (Stage 1)

We use WINOLS to modify nearly all the tunes we develop. We've been using WINOLS since around 2004 probably longer than anyone else in Wales. WINOLS is probably the best software tool available today to modify the contents of factory engine ECUs.

Lots of other map files within the overall map will also need tweaking to work with the changes made such as throttle position, throttle body adjustment and modification of the torque limiters. There’s a lot that goes on behind the scenes to create a well adjusted and balanced tuning file for your diesel vehicle.

For a completely factory standard vehicle we create a Stage 1 remap designed to complement the original systems and work within a good safety margin for the operation of the emissions systems present.

For those eager to bypass or remove the diesel emissions systems (DPF / EGR Valve), we create a Stage 1+ remap designed to complement the original systems and work within a good safety margin.

If you’re interested in really improving your diesel performance with some proper modifications, we can create a Stage 2 remap to tune the car within its new parameters. Examples of the most

Petrol Engines. The Basics

Petrol vehicles can be either naturally aspirated, turbocharged or supercharged. Unlike diesel engines they rely on a spark to ignite the combustion, as such the ignition timing is crucially important to the performance of the engine.

The air/fuel mixture takes time to burn, if the mixture is ignited at the correct point in the cycle maximum pressure will be achieved shortly after the piston reaches top dead centre to create the maximum force to push the piston down the cylinder, maximising the power production of the engine.

The manufacturer settings will be specified by the number of degrees prior to top dead centre that ignition should occur. When this is modified for tuning purposes, advancing the timing would indicate making it happen earlier than the original setting, whereas retarding the timing would make it later than the original setting. A common error is to over advance the ignition causing pinking / pinging, at low rpm this results in loss of power and unburned fuel.
A more serious mistake is to completly get the timing wrong or seriously over advance the timing in which case you get expect pre igntion, do that at high RPM and expect to buy a new engine.

What is needed to tune a Natrually Aspirated Petrol Engine?

The best way to set the ignition timing is using the dynamometer where the engine can be held at a steady speed and load whilst the adjustments are made to optimise the power output. The timing can be slowly advanced until peak torque is reached.
On naturally aspirated engines this is easily attainable, however turbocharged or supercharged engines cannot reach peak torque without detonation so in these cases the timing has to be retarded to account for "knock limit". As ignition is varied, fuel quantity needs to be adjusted.

The stoichiometric ratio for burning the fuel completely is deemed 15:1 (15g air : 1g fuel) however generally most run with the fuel richer than this. Using a data logger and the air/fuel gauge with the dynamometer allows for accurate set up.

There are limitations to what can be achieved with a naturally aspirated engine unless you invest in stage two upgrades which we've listed a few of below:-

Common Natrually Aspirated Petrol Engine Upgrades

• Improved Air Filter
• Better Exhaust Flow (not too much though)
• Throttle Body Upgrade
• Tuned Exhaust Header
• NOS Injection
• Porting
• Forced Induction Conversion

What is needed to tune a Forced Induction (Turbo or Supercharger) Petrol Engine?

Petrol forced induction comes in the form of turbochargers or superchargers.

With petrol engines, adding a turbo is to increase the pressure in the combustion chamber so they tend to be smaller than diesel ones and run at much higher RPM giving a higher boost without much increase in airflow. Petrol turbos also spool up quicker to operate at a much wider range of RPM.

Superchargers use a compressor that works from low rpm giving a good reaction as soon as the accelerator is pressed (turbochargers use exhaust gas flow so there is a delay). It is common for the supercharger to be driven by a belt and pulley on the engine crankshaft.

Supercharged engines are less popular with manufacturers and therefore less common than turbocharged engines but they actually achieve significant improvements in power and torque with tuning. Our highly developed remaps for the Mini and Range Rover supercharged engines are very popular.

Common Forced Induction Petrol Engine Upgrades

• Improved Air Filter
• Better Exhaust Flow (not too much though)
• Throttle Body Upgrade
• Larger Turbo or Hybrid Turbo
• Supercharer Pulley Upgrade
• Larger/Better Intercooler
• Water / Meth Injection
• NOS Injection

The Dangerous of a Mobile Remap or Non Dyno Map

There is no error of margin with a petrol engine. If you have a petrol engine, even if you don't use Llandow Tuning at least go to another dyno operator and get them to tune it. You use a mobile tuner at your own risk, you have been wanred!

Lean Air/Fuel Mixture

Expect a melted valve, melted or cracked head or mealted piston. If the mixture is wrong and too lean the temperate within the engine will be so great that it will simply melt

Incorrect Advance

It is one thing to advance the timing, or variable valve timing to get a little more power. But unless you can monitor knock you are simply taking a chance as to whether you are going to damage the engine. This is the whole point of a rolling road.

High Inlet Temp

As with a diesel, expect uncontroled knock if the inlet temperate get too high. It is easy to overboost the turbo then run the inlet too hot.