A supercharged engine that runs lean can be destroyed in seconds. The standard ECU map cannot run a blower, so the car must be mapped before it is driven hard. This page is what owners described, not a how-to for mapping. Cost figures are from 2013 and the software and services have changed since.
At a glance
- Two routes: send the ECU to a UK specialist, who loads a base map with a rev limit (5,000 to 5,500 rpm in owners' accounts) and then finishes the mapping in person; or use the Dutch OBD Tuner software, which lets you log and adjust the maps yourself.
- 2013 cost comparison from two owners: the specialist route was about £230 for the map, plus fuel and a day to get there, plus about £100 to £200 of remapping time. The OBD Tuner upgrade was about £800 and then you can re-map whenever parts change.
- Learn mode works by driving through the rev and boost range until the engine light stops coming on. One owner described a safety check on the fuel map before you start.
- Fuelling is the risk. A rich base map is safe, a lean one isn't.
Route 1: base map from a UK specialist
- You send them your ECU and they load a base map. In 2013 owners said it carried a 5,000 rpm rev limit; the 2010 install guide said 5,500 rpm at that time. Both are what owners reported.
- A 2012 reply to an Italian owner said the same, and that you send the ECU to the specialist for the base map even when the parts come from abroad.
- You then take the car to them in Norfolk for final mapping. One 2013 owner said that if anything goes wrong on the day, a second visit adds to the cost.
- One owner in 2013 thought this route was cheaper if no other mapping would be needed, but that the other route paid back for anyone who intended to change things later.
- Owners in 2013 also said the fuel maps supplied by this route were rich, and one thought that was a reason catalysts lasted well. That is opinion, not a tested claim.
Route 2: the Dutch OBD Tuner software
The software was written by one man in the Netherlands and had been used on, by one owner's 2013 account, 50 to 100 supercharged conversions since 2009. In 2012 UK owners said it had been talked about for a long time without being ready for general release. A 2012 post from a Dutch owner described how it worked for him:
- He sent his ECU to the developer, who flashed the OBD Tuner operating system onto it. Later the PC software arrived by email.
- He was sent a base map that suited his set-up (LSJ injectors, LSJ throttle body, standard exhaust), and the engine ran on it without problems.
- He then did a learn session by driving, which needs no dyno time: hit every combination of rpm and power so the ECU can learn, including brief high revs in low gears. The software now has smoothing and extrapolation for cells you don't reach.
- The software lets you read and write calibration files, log everything the ECU sees, and compare changes. He kept the OBD cable in the car as a standard accessory.
The developer was cautious about how he sold it, said the owner, because you can damage an engine if you change things without understanding them. In 2018 an owner said a new map can be loaded in minutes. In 2026 a newcomer planned to use it and was awaiting a price from the supplier.
How the learn session was described
One 2013 owner who used it explained it as follows. This is his description, not a procedure, and only one owner confirmed it:
- The ECU runs in closed loop (the lambda sensors adjust the fuelling) at low revs and open loop (fixed fuel tables) at high revs, because at higher revs extra fuel is needed to keep the engine cool.
- To map the fuelling, the ECU is set to open loop across the whole range, starting from a rich base map that over-fuels to protect the engine.
- You drive so as to cover the rpm and boost combinations (about 5 seconds at each rpm band, harder to cover all boost levels), and the ECU works out the fuel trim needed at each.
- On this ECU the engine management light comes on when there aren't enough readings for a cell. You keep driving the same way until it goes out, then move up the rev range until it comes on again. He said it took about an hour and a half.
- His safety checks before starting: make sure the base map is over-fuelling, by entering learn mode and going for a quick drive. If the ECU is reducing fuel, the learned trims show as negative numbers, which means the base is rich and it is safe to carry on. Then keep driving until the light stays out.
Another owner joked that anyone who mentioned mapping their own car on a performance-car forum would be told the car would explode and only a famous mapper could do it. The reply from the first was that this developer had made it easy, but it might not be so on other cars. Take the risk seriously either way.
Other things owners said
- Dyno days were arranged in the Netherlands for owners to compare maps and check full-load fuelling and detonation, at around €40 a run in 2012.
- A 2014 owner who had his car dyno-tested before converting said that a specialist's stage 2 map for the NA ran so rich that the air/fuel ratio spent most of its time in the 10s, where about 12.5 to 13:1 would be the target for best power. That is one car and one map.
- The first start after a conversion can rev erratically. The 2010 install guide said to leave it to settle. See the install guide.
- Changing injectors, throttle body or exhaust means the map needs checking again. See Injectors for supercharged cars and Supercharged boost pressure.
Help wanted
We don't have current prices or availability for either route, the rev limits the specialists use now, or a UK supplier of the OBD Tuner software. If you have had a car mapped recently, please tell us which route you used and what it cost.