Tuning FAQ

The bottom line

• We prioritize quality over quantity.
• We are the longest-established independent tuner in Wales.
• We own and operate all our own master tuning equipment. We have never used, owned, or relied on any equipment from another tuner—let alone acted as an agent for another tuning company. No one else in Wales can claim that.
• We've tuned more cars in Wales than any other Welsh-based tuner.
• We invite you for a free consultation— we’re confident that once you visit, you’ll agree that we’re the best in Wales.

• Why don't they have a workshop? Proper tuning requires controlled conditions, specialized equipment, and a dyno—not just a laptop in a car park.
• What happens when something goes wrong? If a file is bad or causes issues, these tuners rarely have the knowledge to diagnose or fix it. Instead, they rely on their "supplier" to send another generic file.
• They have no real tuning experience. Many mobile and agent tuners are just middlemen with limited mechanical knowledge, selling files they don’t understand.
• No genuine custom tuning. A mobile tuner or agent cannot develop a tune specifically for your vehicle. Instead, they load a pre-made file from whoever their tool is slaved to.
• They do this because they lack the skills. If they had the knowledge and ability, they would be writing their own tunes—not reselling someone else’s.

• If you want 100% factory reliability, do not tune the car.
• If you want a completely "start, drive, forget about it" experience, do not tune the car.
• If you want more power, better response, or different driving characteristics, tuning can be a great option, but it is a choice with trade-offs.
• If you simply couldn't handle the need to pop back for a tweak, don't do it!

• The car must not have a check engine light (MIL), unless the fault is minor and will not interfere with tuning.
• Any existing fault must not affect key tuning parameters such as boost control, fueling, or ignition.
• We will carry out a basic check-over before tuning to identify any obvious issues.

• DPF removal or recalibration
• EGR disable or optimisation
• AdBlue system recalibration or removal

• Turbo underboost or overboost errors
• Fuel pressure faults affecting injection and control
• Severe misfires or ignition system faults
• Major sensor failures (e.g., MAF, MAP, lambda, or knock sensor faults)

• No air leaks in the induction system – boost leaks or vacuum leaks can cause incorrect fueling and poor performance.
• Fuel pressure is stable and controllable – a weak or inconsistent fuel supply can lead to poor results and engine damage.
• No exhaust leaks – leaks before or near the lambda sensor can cause inaccurate AFR readings.
• The engine is mechanically sound – compression and leak-down tests are advisable on high-mileage or modified engines.
• All sensors are functional – MAF, MAP, IAT, lambda, and knock sensors should be operating correctly.

• A wideband O₂ sensor and controller – improves AFR accuracy and tuning precision.
• Exhaust Gas Temperature (EGT) sensors – helps prevent excessive heat buildup.
• Boost pressure monitoring – a boost gauge or reliable ECU logging helps track turbo performance.
• Knock detection equipment – improves ignition tuning safety.
• Oil pressure and temperature gauges – critical for higher performance vehicles.
• New spark plugs of the correct heat range – reduces misfires and improves consistency under load.
• A healthy ignition system – coil packs and leads must be in good condition.
• Fresh fuel of the correct octane – poor fuel quality increases knock risk.

• Fuel supply issues – weak fuel pump, clogged injectors, or incorrect fuel pressure regulator setup
• Boost leaks – leaks in intercooler piping or vacuum lines
• Exhaust leaks – pre-turbo or pre-lambda leaks affecting AFR readings
• Cooling system faults – overheating, thermostat issues, or radiator problems
• Faulty sensors – MAF, MAP, lambda, knock sensors, or TPS faults
• Electrical faults – poor wiring, grounding issues, or ECU communication errors
• Clutch slip – makes load testing and calibration unreliable
• Engine mechanical faults – low compression, misfires, or excessive oil consumption

• Checking for stored ECU fault codes
• Inspecting for obvious vacuum, boost, or exhaust leaks
• Ensuring proper fuel pressure and delivery
• Monitoring ignition system performance
• Checking cooling system condition

• We perform diagnostics to identify faults preventing tuning.
• We work methodically, addressing issues one by one.
• Common faults include boost leaks, fuel pressure issues, misfires, sensor failures, and ECU communication errors.

• Diagnosing and resolving faults is outside the scope of a tuning session and is chargeable.
• We cannot predict the final cost upfront, as faults require investigation.
• If you have a budget constraint, you must tell us before diagnostics begin.
• If no budget is set, we will continue working until the vehicle is tuning-ready or you instruct us to stop.

• If the job takes longer due to unforeseen issues, additional labour will be charged.
• If new faults are discovered, we will pause work and discuss options before proceeding.
• If you wish to set a spending limit, this must be agreed before work begins.

• You supply an uprated turbo, but additional fittings or gaskets are missing. These will be chargeable.
• Seized or corroded bolts extend labour time beyond the estimate.
• A diagnosis reveals that a larger repair is required, in which case a revised estimate will be provided.

• Basic servicing
• Simple component replacement

• All parts are confirmed with you before ordering.
• Parts fitted to a vehicle are non-refundable once installed.
• Customer-supplied parts must be approved before fitting.

• The warranty for customer-supplied parts is your responsibility and must be handled directly with your supplier.
• If a customer-supplied part fails, all labour to remove or replace it is chargeable.
• We do not cover labour costs for failed customer-supplied parts.

• Requested old parts will be made available at the time of vehicle collection.
• If you forget to collect them, or do not request them in advance, they may be disposed of.
• There is no guarantee that old parts will still be available at a later date.

• 0–3 months: Parts and labour covered.
• 3–6 months: Parts only (labour chargeable).
• After 6 months: No warranty applies.

• Stage 1 is the basic level of Tuning a vehicle where no modifications have been made to any engine system. It is completly safe and will not require you to change how you look after the vehicle
• Stage 1 + is the next level, typically you need to modify the exhaust system to get to Stage 1+. Modiciations that enable a Stage 1+ map include DPF and EGR Deletes.
• Stage 2 capablity is reached when you add inducation modifications like updated Intercoolers, Air Filters, Induction Pipes etc
• Stage 3 incorporates everything above stage 2. The kind of modifcations range from larger turbos to a wild cams. It really means VERY CUSTOM.

• Stable fuel pressure with a high-quality pressure regulator.
• Wideband O2 sensor for accurate air-fuel ratio monitoring.
• Boost control (if the vehicle is turbocharged).
• Engine kill switch for safety.
• Balanced ITBs if fitted

• Fire Control System
• Oil pressure and temperature gauges to monitor engine health.
• Fuel cut-off switch for safety in case of emergency.
• Electronic fuel pressure sensor connected to the EFI system for better logging and diagnostics.
• EGT Sensors If running boost it is ideal to have EGT sensors to safeguard the engine.
• Knock detection system to safeguard against detonation.

We are happy to get EFI systems up and running but we won't be the scape goat for a poor engine build or the wrong choice of fuel pressure regulator. If a bolt drops in the engine whilst its on the dyno, a pipe comes off the engine and the oil spills everywhere, a valve drops. These aren't things we'll be covering, indeed if it spills oil you're paying for the cleanup.

• If the engine has been modified beyond the EFI conversion (e.g., different cams, turbos, increased compression), no warranty will be provided.
• If we have not supplied and fitted the EFI system, then no warranty will be provided under any circumstances.
• If the engine is build to make more power than stock, motorsport use or fast road use. We simply won't be proiving a warranty for this kind of use

• We can only guarantee reliability when we control both the ECU installation and the vehicle's calibration.
• Modified engines introduce unknown variables, making long-term reliability unpredictable.
• Standalone ECUs and EFI conversions require precise setup—if installed by someone else, we cannot verify the quality of the work.

• Faulty or non-functional sensors (e.g., AFR sensor, MAP sensor, knock sensor).
• Mechanical or electrical issues affecting engine performance.
• Boost leaks, fuel pressure problems, or misfires.
• Unstable ECU signals or communication errors.

• If your AFR sensor is faulty and gives incorrect readings, you must replace it before tuning can continue.
• If additional work is required to resolve an issue, further tuning time will be chargeable.

It is our opinion that any vehicle making more than stock power should have knock detection installed within the ECU or a dedicated controller, how you present the vehicle to us is your decesion.

• Your engine must have Bosch Knock Sensors installed, which we can connect to during tuning. We will not be fitting knock sensors within the fixed price of a tuning session
• Ideally, your ECU should have built-in knock detection or use a seperate conroller that we can calibrate and utilize as part of the tuning process. If it isn't present in the ECU maybe you need another ecu!

• A sound exhaust free of leaks
• New points in the distributor if points are used
• A sound carb, i.e. one which isn't worn out
• A method to control the fuel pressure to the carb or injectors
• A FULL tank of fuel
• A new set of spark plugs

• Standalone ECUs
• Hybrid turbos
• Injector testing and calibration
• Throttle body modifications

• Your fuel pump has failed – we can diagnose and replace it.
• A sensor cable is damaged – we can repair or replace it.
• Your engine ECU has water damage – we can source and fit a replacement.

• You have a hole in your engine block from a piston failure – you may need an engine builder.
• Your automatic gearbox is seized – you may need a gearbox rebuilder.

• Forced Induction Conversions – If you’ve added a turbo or supercharger to a naturally aspirated engine, we may need to modify certain components to ensure compatibility and accessibility.
• Carburetor Upgrades – If you’ve fitted different carburetors, access may be a concern. For instance, if the carb is positioned too close to a bulkhead, modifications (like an access panel) may be required.

• Flash Counters: Many modern ECUs keep a log of how many times the software has been updated. Even if you return the ECU to stock, a dealer tool can still flag that an unexpected number of flashes have occurred.
• Checksum Validation: Manufacturers store digital signatures of factory ECU software versions. If a tune alters critical parameters, the ECU checksum may no longer match the expected factory values.
• Diagnostic Data Logging: Some manufacturers, especially brands like BMW, Mercedes, and VAG, actively log peak boost levels, torque limits, and ignition timing adjustments. If a dealer inspects these logs and finds values outside the expected range, they may suspect tuning.
• Online Software Syncing: Some modern vehicles automatically report ECU software versions to the manufacturer when connected to online dealer diagnostics. Any mismatch from the factory version can trigger a flag.
• Hidden "Flash History" Storage: In certain vehicles, ECUs store metadata of past calibrations, even if the stock file is reinstalled.

• Avoid dealer visits unless absolutely necessary.
• Disable automatic software updates or online system syncing where possible.
• Before a dealer visit, consider having your tuner return the ECU to stock (though this won’t reset flash counters).
• Use a reputable tuner with master tools that can properly restore the ECU when needed.

• Tuning refers to the modification of a vehicle’s engine or ECU parameters to improve performance, efficiency, or drivability. Tuning can involve software adjustments, hardware modifications, or both.
• Remapping specifically refers to modifying the ECU’s internal maps or calibration curves to alter performance characteristics. This can be done for increased power, better fuel economy, or even limiting output for specific use cases. Unlike generic "file flashing," proper remapping involves custom adjustments tailored to the vehicle.
• Chipping (Chip Tuning) is an older term from the era when ECUs used replaceable EPROM or PROM chips. In the 1980s and 1990s, tuners had to physically remove, modify, and reinstall these chips to change ECU parameters. The term became widely associated with "Superchips" and similar tuning brands of the time.

• Is it a £4 bottle of plonk or a £20 bottle?
• How has the file been tested?
• What does the person installing the remap know about cars? Can he perform an initial inspection to ensure there isn't some underlaying issue with the car?
• If it all goes wrong and he bricks the ECU, what is he going to do about it? Does he have the equipment to fix it? Is he simply going to do a runner? Or might he just pass the buck and blame the car. Don't worry if this happens call us, we fix lots of "tuned" cars

• Slave tools encrypt the ECU data, meaning the tuner cannot directly modify or analyze the calibration.
• The ECU readout has to be sent to a Master tool holder (usually a remote tuning company), who then modifies the file and sends it back.
• The so-called "tuner" has no actual control over the changes being made to your vehicle.

• They are not tuning your car—they are just middlemen selling pre-modified files.
• They cannot adjust or optimize the tune in real-time, meaning if something isn’t right, they have to go back and forth with whoever controls the Master tool.
• If an issue arises, they have no way to diagnose or adjust the file themselves.
• There is no real custom tuning involved—your car gets a generic map that may not be fully optimized for your specific setup.
• If you need adjustments in the future, you are locked into the Master tool provider and cannot switch without starting over.

• Genuine custom tuning tailored to your car.
• Real-time adjustments and troubleshooting.
• The ability to make refinements without needing a third party.
• Complete control over the tuning process, ensuring safe and effective results.

• We have been providing independent, in-house tuning since 2004.
• Unlike our competitors, we have never been an agent or reseller for another tuning firm.
• Every file we create is custom-tuned in-house using Master tools, not slaved to another provider.
• Our facility is equipped with dealer-level diagnostics and full dyno testing capabilities.
• We specialize in bespoke calibrations rather than loading generic maps.

• Jorvick Tuning, GotBoost Tuning, and SCM Remaps have all operated as resellers for larger tuning firms at some point.
• How custom are off the shelf custom tunes? Typically bought in from third parties.
• Limited in-house expertise means they often cannot diagnose or modify files properly.
• If an issue arises, they are dependent on whoever supplies their files, leading to delays and uncertainty.

• ECU programming and flashing.
• Module coding and adaptation.
• Advanced fault diagnostics beyond what generic tools can read.
• Security coding, key programming, and immobilizer work.

• German Brands: BMW, Mercedes-Benz, VAG (VW, Audi, Seat, Skoda, Porsche).
• British Brands: Jaguar, Land Rover.
• American Brands: Ford, GM, Chevrolet.
• European Brands: Vauxhall, PSA (Peugeot, Citroën, DS), Fiat, Renault.
• Italian Brands: Ferrari, Maserati, Alfa Romeo.
• Japanese Brands: Nissan, Subaru, Honda, Toyota, Mazda.

• You bring in a high-value vehicle which, after inspection, requires major work (e.g. engine rebuild or carburettor overhaul). We do not want to reach the end of the job only for you to say you cannot afford or did not authorise the work.
• You bring in a modified car for tuning, but additional repairs are required to make it safe. Any spending limit must be declared before work begins.

• Mechanical or electrical faults preventing safe tuning.
• Vehicle issues that distort results and make accurate calibration impossible.

• Labour is charged in one-hour increments at £85 per hour.
• All parts, external services, and third-party costs incurred while working on your vehicle are chargeable.

• If the examiner confirms our invoicing and workmanship are correct, the outstanding invoice must be paid in full within 48 hours.
• If the examiner identifies issues with our workmanship, we will rectify them at our own cost, in line with their findings.
• Unless the examiner states otherwise, any outstanding invoices remain payable.
• We will initially cover the cost of the inspection; however, if no fault is found, the customer must reimburse this cost.

• Issue formal payment reminders.
• Instruct a debt recovery agency.
• Commence legal action through the Small Claims Court.

• Unless otherwise agreed, the full balance is due within 48 hours of invoice issue.
• Vehicle collection does not void or cancel an invoice.
• Only an official credit note nullifies an invoice.

• No warranty claims will be honoured while an invoice remains unpaid.
• Further work or inspections will not be carried out until the balance is cleared.

• Refused future services.
• Subject to debt recovery and additional collection fees.
• Recorded internally and declined future bookings.
• Subject to legal action to recover outstanding balances and associated costs.