Understanding Stage 1, Stage 1.5, and Stage 2 Remapping

Stage 1 Remaps A Stage 1 remap is considered a basic and safe introductory tune for stock, unmodified vehicles. It works within the limitations of the factory-fitted engine components to provide modest but noticeable improvements in performance.

On petrol cars, we use a Stage 1 tune to:

• Safely raise the turbo boost pressure within its tested threshold, usually by 2-3 PSI
• Advance the ignition timing degrees for increased combustion efficiency
• Enrich the air/fuel ratio slightly to account for the extra boost demand

Together this can result in peak power gains of 10-15% while avoiding excessive heat or stress on stock pistons, rods, bearings and factory turbocharger systems. Low-end and mid-range torque is particularly improved.

On diesel vehicles, Stage 1 remapping is focused more heavily on economy and smoke reduction maps to:

• Optimize injection timing cycles for increased fuel atomization
• Better EGR valve control to reduce throttling losses
• Lower SCR dosing requirements through refined boost pressure maps

This leads to improved MPG by 5-20% in many diesel engines along with enhanced drivability, though modest 15-20% torque gains are still achieved.

Stage 1.5 Remaps:

Among reputable UK tuners, "Stage 1.5" engine remapping is generally avoided. This refers to pushing the limits of the stock turbochargers, fuel injectors, intercoolers and supporting mods beyond their reliable capabilities in search of more peak power.

By running unsafe turbo boost levels on unmodified engines, there is high risk of blowing turbo seals, cracking pistons, warping conrods and causing general engine damage over time due to excessive cylinder pressures and heat generation. Proper Stage 2 remapping with appropriate hardware is a safer approach when wanting to tune more aggressively.

Stage 2 Remaps:

Once you have fitted complementary engine modifications like a front-mount intercooler, free-flow exhaust, cold air intake and potentially larger turbocharger or upgraded fuel injectors, the engine is truly ready for a more aggressive Stage 2 tune.

A Stage 2 ECU remap takes full advantage of the engine's new ability to ingest more air and improved fuel/timing control to then safely increase performance parameters like:

• Turbo boost pressure
• Fuel rail pressure
• Injection timing and duration
• Ignition timing advance

Stage 2 petrol engine remapping can reliably achieve peak horsepower/torque gains upwards of 60-80% thanks to the headroom provided by bolted-on supporting modifications.

Diesel engines also see enormous increases in torque, power, throttle response and MPG during Stage 2 tuning. This is made possible by improved fuel and timing maps to better take advantage of upgraded fuel delivery and airflow capabilities from larger turbos, intercoolers, intakes, etc.

In Summary:

Stage 1 remapping is ideal for lightly modifying stock engine cars and vans for basic drivability and MPG enhancements. Stage 1.5 goes too far on unmodified vehicles, while Stage 2 properly capitalizes on aftermarket parts to aggressively remap for vastly stronger performance gains.