Big Fish Tuning

Info and FAQs

Types of Map

Custom Map

A Custom map is where every static map starts from on a software build. The map is read from the car then adjustments made to it by the technician to try and obtain what the customer wants from the car, using his skill and experience of the both the ECU and the engine type to achieve what the customer is looking for and to take into consideration any modifications that have been made. He will then either road test the car with diagnostic equipment recording the details or run it up on a artificial test, such as a rolling road. He will then review the results and tweak further if required. Some companies do this first run on the dyno and deliberately leave a margin for improvement, which they then apply for a second run which leaves the customer with an immense sense of satisfaction that the person doing it has tweaked it to their car. Truth is, they could have done that to start with – and yes there are a number of companies that do this!!

Of course, no technician is going to start from a blank canvas, either in mind or actual mapping and will over lay what they have done previously time and time again in the main anyway, otherwise he will be there for days. The downside to a custom map is of course it is un-tried, un-tested and there is little knowledge as to any longer term affects, other than that of the person doing the mapping. In the main though, a custom map will produce roughly the same power as a generic map.

Live Mapping

This is what most people think Custom Mapping is, but it is very very different. This is mapping done with the car running and driven on the dyno, not stopped and having the map loaded on with the engine off and then been given a dyno run. Live mapping is what companies do mainly for competition cars and specially modified cars with real hardware changes (i.e. not just an induction kit or exhaust) and of course this is much more expensive.

Generic Map

In reality a Generic map doesn’t exist in modern tuning. Most cars now have software that is unique to them as it includes data such as chassis number, so most tuning companies will download the map that is on the vehicle and work from that map wherever possible. What is generic is the knowledge the tuner has of that engine type. Basically, no one will start with a blank mind, so all prior knowledge will be put into the map and then tweaked accordingly. Years ago you could buy “chips” for your ECU – these were indeed generic as they were very basic data on the older ECU’s and you could swap them in and out as required, this is not possible and in fact the vehicle wouldn’t even start now if you did similar with modern mapping data.

Lets talk torque

Torque is the measure of power of a moving (rotating) force applied to an object around its fulcrum (pivotal point). In a car, ‘torque’ expresses the effort exerted on a shaft to move the vehicle along. When torque is great enough to move a shaft through a given distance in a given time, is ensures that the ‘job’ of moving the car is done: such as ‘job’ is expressed as ‘power’ and measured as horsepower.


  • How long will I have to wait for an appointment?

    Typically we book up a week in advance, though we do some times have last minute appointments so it’s always best to phone and check.

  • How long will my appointment take?

    Custom Mapping - Stock Vehicles

    Appointment slots for custom maps on stock vehicles are roughly 3-4 hours. We do one morning slot between 9am and 12pm and an afternoon slot between 12pm and 4pm.

    Custom Mapping - Modified Vehicles

    Appointment slots for modified vehicles at stage 2 or 3 are full day slots between 9am and 4pm.

    Appointment slots for modified vehicles or project cars at stage 3/4 will usually need to be booked in at the beginning of the week and left for a few days for multiple power runs and stages of tuning.

    DPF Removals

    DPF removals take at least one working day however we may need your vehicle in for two days if any additional parts are required as part of the Dpf removal.

  • Do I have to wait on site?

    You do not have to wait on site however we do have a full dyno view waiting room for you to view your vehicle whilst it is in our workshop.

    If you would prefer not to wait on site there are plenty of cafes nearby, a soft play area, and even a golf club. It’s also just a short 15 minute walk into the nearby town of Stokesley.

    Please be aware that our workshop has a minimum age of 18 due to the noise levels and embedded rolling road. Therefore if you are accompanied by children under the age of 18 we ask that you remain off site in between drop off and collection to ensure their safety.

  • Can you provide a courtesy car?

    We can provide a courtesy car. We require proof of insurance for all drivers for which there are a couple of options:

    • If you are over 25 you are usually covered to drive other vehicles with the owners permission with a cover of third party fire and theft.
    • You can take out fully comprehensive day cover through a number of providers.
  • Do you do appointments at the weekend?

    We are open on Saturday’s between 8am and 12pm. Saturday appointments are always the first to be booked up so to avoid disappointment please do book well in advance of your required appointment date. Please note that not all vehicles are eligible for Saturday bookings as some vehicles need more time than others.

  • Where are you?

    We are based on Ellerbeck Way in Stokesley Business Park. If you have trouble navigating the maze then please do give us a call on 01642 711552 and we’ll guide you in.

  • What are your opening hours?

    Monday to Friday - 9am - 4pm

  • Do I need to update my warranty provider?

    If your vehicle is still within warranty you should be aware that mapping of any kind can invalidate your warranty so please do make sure you speak to your warranty provider before any services are carried out.

  • Do I need to update my insurance provider?

    Yes you do need to let your insurance provider know if you have had any mapping on your vehicle. Failure to do so could result in a disputed claim if you ever need to use your insurance for damage or incident.

  • Deposits and Cancellation Policy

    We take a £50 deposit for every half day slot booked. This deposit is taken to ensure that customers arrive on the day for their appointment as we have had issues with this in the past. The £50 deposit will come off your final bill on the day of your appointment.

    If you can no longer attend your appointment we do require at least five days’ notice to guarantee the return of your deposit. If the notice given is less than five working days your deposit will only be refunded if we can fill the requested time slot of your booking.

  • Minimum Fees - IMPORTANT

    Unfortunately, it has become necessary to introduce the following minimum fees. Once this form is signed and accepted the following minimum charges will apply.

    1) Mechanical Issues If your vehicle is deemed unfit to tune due to mechanical issues then a minimum fee of £150.00 per half day slot to cover diagnostics, rolling road time and time spent. Your deposit will be deducted from this fee.

    2) Pre-Existing Tuning

    Whilst we accept that not everyone is aware of pre-existing tuning present on the vehicle it does take longer to detect, diagnose, and move forward as planned.

    Please be aware that pre-existing tuning causes delays and as such there are fees to correct existing mapping.

    a. If you have informed us in advance of the pre-existing tuning, then fees to cover this have already been built into your quoted price. b. If you have NOT informed us of any pre-existing tuning and wish to proceed with a Big Fish Tuning custom tune, an additional fee of £100 will apply to cover the time required to correct it. c. If you decide to abort the session upon the discovery of the pre-existing tuning, then a minimum fee of £200 per half day slot is payable to cover time lost. Your deposit will be deducted from this fee.