Pre-Tune Notes and Dyno Tuning Checklist


Pre-Tune Notes and Dyno Tuning Checklist

There are many variables that affect the performance and reliability of any vehicle. Tuning is one of the most important of these variables. However, good tuning practices by themselves will not necessarily produce a reliable well-performing vehicle.

We ask that you make sure your vehicle is mechanically sound, fit for tuning, and not likely to impose any danger to any person working on it. Please ensure that you take the time to go over this list and understand the implications that these factors have on your vehicle. If in doubt, feel free to ask any of our staff.

Fuel Quality – The fuel octane rating is VERY IMPORTANT as this is a measure of the fuel’s resistance to detonation. Higher octane fuel is desirable in most cases as it will allow more power to be extracted from an engine without detonation. However, it is essential to note that once your vehicle is tuned with a particular grade of fuel, the engine can no longer be safely run on a lower grade of fuel. This makes the choice of fuel used during the tuning process a very important decision. Please ask the NZEFI staff about the likely fuel requirements for your application as well as the option of custom tunes for multiple fuel types.

Fuel Quantity – In most cases a full tank of fuel will be sufficient, however this may not be the case in some applications with small fuel tanks, longer tuning times or high fuel consumption. If unsure, please ask NZEFI staff for an estimate on your fuel requirements. If more than one tank full of fuel is required for your tune, please supply filled fuel containers with your name clearly written on the outside of the container(s). If your car does run out of fuel during the tuning process and you have not provided replacement fuel, then in addition to the fuel cost, you will be charged at the full dyno rate for the time it takes for us to get more fuel.

Fuel Pump and Filter – One of the parts in your vehicle that degrades over time is the fuel pump. Therefore, even if the fuel pump in your vehicle was originally up to the task, this may no longer be the case. Additionally, modified vehicles with increased engine performance often have higher fuel flow requirements when being operated under full load/power. Therefore if the fuel pump hasn’t been upgraded then you should consider having this done before your tune. The price of fuel pumps has dropped quite a bit over the years and NZEFI can supply and fit a new upgrade pump to most vehicles. In some cases the car’s fuel pump wiring may also pose an issue with excessive voltage drop and may need to be upgraded. If required, we can test fuel pump and wiring performance to determine if it needs to be replaced before tuning. If we begin tuning and find that the fuel pump is inadequate then we may need to upgrade the pump during the tuning process in order to complete the tune – this will work out more costly for you. Replacing the fuel filter is also recommended if this hasn’t been done recently.

Coolant and Lubricants – Ensure your vehicle has had a recent oil change (5000km or less) and all oils/lubricants are topped up to the appropriate level. Also verify that the cooling system is correctly filled and bled and that the radiator, water pump and thermostat are all in perfect working order. NOTE – All coolant and/or oil hoses must be securely fastened and not be pushed on to fittings without a proper rolled bead or another system to stop them popping off under pressure.

Intake System – In the majority of cases, NZEFI will leak test your intake system before tuning to identify any significant leaks. If any of these are found then we will need to take the required steps to fix them before tuning begins. Some leaks may be quick and easy to fix such as tightening a hose clamp or replacing a rubber/silicone joiner or vacuum line. However, repairing other leaks can be time consuming and/or expensive. Examples include missing/damaged intake manifold gaskets, faulty blow off valves and poorly fabricated intake/intercooler piping. For forced induction applications we recommend beads to be added to the ends of all intake/intercooler piping to stop them popping off during tuning. We also do not recommend using ultra-wide ‘T’ bolt hose clamps. While we can fix any leaks that are found, fixing some leaks can cause delays which potentially could result your vehicle missing its scheduled dyno booking. Therefore we recommend carefully checking for any obvious issues prior to dropping your vehicle off for tuning.

Fuel Injectors – Vehicles with performance upgrades often require upgraded fuel injectors. Feel free to discuss your injector requirements with us. Also, please check around your fuel injectors that there are no leaks – if it looks wet around where the injector goes into the fuel rail and/or the manifold, the injector seals may need replacing. We have the parts for most brands of injectors available at NZEFI should this be the case.

Air Filter – Your air filter should be replaced beforehand if it is in poor condition or is overly dirty. If you have a re-usable one make sure it has been cleaned using the manufactures recommended method.

Air Flow Meter/Sensor – If your car has one then this is a very important sensor that needs to be in good condition and not out of calibration. In some cases these can be cleaned with a can of CRC Air Flow Meter Cleaner. Do not risk using any product that is not specifically intended for this purpose as there is a risk of damaging the sensor.

Air/fuel ratio (Lambda) Sensor Boss – For correct measurement of your engine’s air to fuel ratios using our wide-band lambda meter, we require a 17-20mm hole to be drilled and a boss with an M18x1.5 thread to be fitted in your exhaust system. We realise that this is not a requirement at all tuning shops, however this allows for more accurate measurements to be made than with an extension fitted to the tail pipe. This results in a better overall tune for your vehicle and the cost of having a boss fitted by NZEFI is very small. After the tune we can block the hole with an M18x1.5 plug. With naturally aspirated engines the boss should be mounted just after the collector. On turbocharged engines, this must be fitted after the turbocharger. High-powered turbocharged applications must have the boss mounted approximately 1m downstream from the turbocharger, to minimise the risk of the sensor overheating and giving a false reading. Some vehicles may already have a boss fitted for a narrow-band lambda sensor. If this sensor is not required by the engine management system, then this boss might be suitable for our wide-band sensor. If the narrow-band is required by the engine management system for closed-loop operation, then a second boss will be required for our sensor.

Exhaust System – Firstly please ensure that your exhaust system is in good condition with no leaks before the lambda sensor(s). The exhaust system also needs to be fit for the intended purpose. Stock exhaust systems are often somewhat restrictive and can be a restriction when trying in increase engine performance. Likewise modified exhaust systems may also not always be fit for purpose if they do not have correctly sized piping and/or mufflers for the application. Some can be too loud, others can be too restrictive and in the worst examples both of these problems can occur together. A well designed performance exhaust will strike a good balance between noise and power. At NZEFI we can supply or fabricate an exhaust system to suit your requirements.

Wiring – The engine harness should be well protected and free of any damaged wiring or connectors. Wiring running through bulkheads should use a grommet or specific bulkhead connector. Old wiring with corroded copper strands or missing insulation should be replaced. Broken or cracked connectors (or connectors missing locking tags or spring clips) should be replaced. Wiring should be joined with proper OEM-grade splice crimps and not twisted, taped or soldered together. Poor connections can be time consuming to diagnose which costs time and money, so it pays in the long run to make sure your wiring is up to the task. At NZEFI we stock a large range of wiring products and also offer an in-house wiring/installation service.

Keys & Locking Nuts ­­– NZEFI uses a Dynapack Hub Dyno. For tuning cars, we will need to remove your driven wheels and bolt on adaptors for tuning. Therefore if your car has locking wheel nuts or a special wheel nut removal tool to take the wheels off, make sure it is in the car and the NZEFI staff knows where it is. If by chance your car has a different key for the ignition and the doors/boot, please make sure we have all the keys, we may be required to get into the boot to check or replace things like the fuel pump etc.

General Check Over – Finally, please give your vehicle a general check over to identify any potential problems that it may have during the tuning process. One example would be a very slow oil leak that we need to periodically check. Please make sure that the NZEFI staff are made aware of any potential problems and that you make a note of them on the indemnity form. Except for the minor problems listed above (out of fuel, intake leaks, etc) we will not perform any other repairs to your car without first contacting you and getting your permission. We will need to contact you if, during your tune, we run into any problems that need to be fixed before tuning continues. Please make sure that we can reach you on the number that you have given on the indemnity form.
Targets & Limits – If you have target power, torque or boost levels that you do not want to be exceeded then please make sure that NZEFI staff are made aware of these and make a note of them on the ‘Tuning Details and Indemnity Form’.

Finally, feel free to come and watch your tune being performed from the comfort and safety of our viewing area. Thank you for choosing NZEFI for your tuning needs. We look forward to delivering the highest level of service and workmanship.

Dyno Tuning with NZEFI's Dynapack 4WD Dyno