A Stage 2 remap is the next step after Stage 1. Stage 1 is software only on a standard car. Stage 2 pairs a more advanced map with hardware that lets the engine breathe and stay cool at higher power. This guide covers which parts a Stage 2 build usually needs, why each one matters, and what the options are on a diesel.
If you haven't read it yet, start with our guide to a Stage 1 remap in Hertfordshire. It explains how remapping works and what we do on the day.
What is Stage 2 tuning?
At Stage 1 the map is limited by the standard hardware: the intake, the intercooler and the exhaust. Stage 2 upgrades those parts so the engine can safely run more boost and hold its power for longer, especially on repeated hard runs or hot days.
The exact parts list depends on the car. As a rule, a Stage 2 build includes:
an upgraded intake
an uprated intercooler or charge cooler
a high-flow downpipe
a Stage 2 ECU map, and often gearbox (TCU) tuning
performance spark plugs on petrol engines
Mac Tuning has developed its own software for most vehicles over years of testing and research. Every Stage 2 map is custom-tweaked for the specific car and the parts fitted to it, rather than being a generic file.
Stage 2 parts for turbo petrol cars
Intake
A higher-flow air intake cuts restriction ahead of the turbo and helps it draw in the extra air a Stage 2 map asks for. On its own an intake makes little difference. With a map set up to use it, it's part of a package that works together.
Intercooler or charge cooler
This is the most important Stage 2 part on most turbo cars. More boost means hotter intake air, and hot air means the ECU pulls timing and power. An uprated intercooler keeps intake temperatures down, so the car makes consistent power instead of fading after a couple of pulls.
Downpipe
The downpipe connects the turbo to the rest of the exhaust and is often the main restriction after the turbo. A sports cat downpipe lowers back pressure, helps the turbo spool and gives the map room to make more power. De-cat downpipes are also available.
Spark plugs (petrol only)
At higher cylinder pressures, standard plugs can start to misfire. A colder performance plug gives a reliable spark at Stage 2 power levels and is a cheap part that's easy to overlook.
ECU and gearbox tuning
The Stage 2 map is written for the parts on your car. It adjusts boost, fuelling and ignition timing to suit the new hardware, within limits that keep the engine healthy.
On automatic and DSG cars, gearbox tuning is worth doing at Stage 2. It raises torque limits so the gearbox can handle the extra torque, and sharpens shift times. Our original-software rule still applies: we save your standard software first, so the tune can always be reversed.
Stage 2 on BMW, VW Golf and Audi
Some of the most common Stage 2 cars we see in Hertfordshire are:
BMW 20i (B48) and 20d (B47). The 120i, 320i, 120d, 320d and 520d. The B48 in particular responds well to an intercooler and downpipe with a Stage 2 map.
VW Golf GTI, Golf R and GTD. The EA888 petrol engine is one of the most popular Stage 2 platforms around.
Audi S3, A3 40 TFSI and 2.0 TDI models. These share most of their hardware with the Golf.
For the expected figures on your car, use our power gains check and we'll talk you through what's realistic.
Stage 2 for diesels: DPF, EGR and AdBlue deletes
On a diesel, the hardware side of Stage 2 is usually the intercooler and intake. Some owners also choose to have the emissions systems switched off as part of the build. We offer these as software solutions, and each takes 45–60 minutes:
DPF delete. Software that stops the ECU managing and monitoring the DPF. A physical exhaust modification is still required for the software to work, and that work is carried out separately.
EGR delete. Software that switches off EGR control and monitoring. Depending on the vehicle, the valve may also need to be blanked or disconnected separately.
AdBlue delete. Software that switches off the SCR system, so no AdBlue warnings, countdown or limp mode linked to it.
With deletes you get what you pay for. We often put right poor deletes done elsewhere, where warning lights come back or the car goes into limp mode, so it's worth having it done properly the first time.
De-cat downpipes and AdBlue, DPF and EGR deletes are intended for off-road and motorsport use.
Before you go Stage 2
A Stage 2 car is only as healthy as the engine underneath it. Problems after a remap usually come down to an underlying engine fault, poor maintenance, or a sensitive engine that needs the power dialling back slightly. That's why we check every car over before tuning, and why we may suggest sorting servicing or a worn part before a Stage 2 build. If you're planning a track day, our track mods page covers brakes and cooling too.
Stage 2 tuning in Hertfordshire
We're based in Ardeley, Hertfordshire, a short drive from Stevenage, Hitchin, Letchworth, Hertford and Welwyn, and we see cars from all over the UK. We've tuned over 5,000 cars and have over 300 five-star reviews, which you can read on our reviews page. You can spread the cost of parts and tuning with Klarna or Clearpay.
Stage 2 FAQs
What's the difference between Stage 1 and Stage 2?
Stage 1 is software only on a standard car. Stage 2 adds hardware such as an intercooler, intake and downpipe, with a map written for those parts.
Do I need every part for Stage 2?
Not always. It depends on the car. We'll tell you which parts make a real difference on yours and which you can skip.
Can a Stage 2 tune be reversed?
The software can, always. We save your original software before writing the new map. Hardware would need refitting separately.
Can I go from Stage 1 to Stage 2 later?
Yes. Many customers start at Stage 1 and add parts over time. We update the map once the hardware is fitted.
Plan your Stage 2 build
Tell us your car and what you want from it, and we'll put together a parts list and map that suits. Book online or get in touch.
