Tunit Diesel Performance :: FAQs

By: Tunit Diesel Performance  05/12/2011
Keywords: Vehicle, engine, Fuel Economy

Can I try a tunit before I buy one?

Actually, yes. If you are willing to travel to the premises of any of our distributors, we offer a 'try before you buy' policy where we fit the Tunit, take you for a test drive to make sure you are completely happy. If you don't want the Tunit for whatever reason we will remove it and charge the fitting fee. This way you can be sure about your purchase before you spend your money.

Can the Tunit put any strain on my engine or damage my engine?

The tunit is designed and programmed in each case to improve your performance no more than the engine's safety limits will allow. We have never had an incident to date where the tunit has been responsible for any engine or engine related problem. The longevity of an engine is determined by how it is looked after and driven. The tunit is installed on many high mileage vehicles and has been running on them for 5 years and more. The tunit is programmed carefully so as not increase strain on the engine and any of its components such as turbo and injection equipment. Turbo boost pressure is not directly altered but a gain in boost is achieved as a by-product of extra exhaust gas flow. The Tunit now comes with a 1 Year Engine and Driveline warranty for your peace of mind (subject to conditions-please see www.tunit.com/warranty)

Does the Tunit need any maintenance?

None at all, however the tunit should be fitted in a dry place free from excess vibration and heat.

How easy is the tunit to adjust?

The tunit is very easy to adjust. Each tunit has a 9 position dial that is reached by a clear plastic removable cover. The dial will always come set at 5. You may turn the dial up or down to achieve better power or fuel economy. The tunits II, III & IV are adjustable in a similar way but work with a screw with no fixed positions. If you have a specific application you need to adjust for, such as towing or using the tunit in conjunction with further engine modifications, we can alter far more parameters with a laptop tune (available at all our distributors), and tailor the tunit to your preference, i.e. bringing the power in further down the rev range or extending it to higher revs. Please contact a distributor for details.

How long does the tunit take to fit?

It does vary from vehicle to vehicle. Some unit are fit in 5-10 minutes others take up to an hour, but once fit can be removed in less time . As an average most are fit within 30 minutes.

I have changed my vehicle and want to fit the Tunit to my new vehicle, how do I know if I can do this?

If the Tunit is not the same type, i.e. VP, CR or PD then it will not fit and you should contact your local distributor to see if a part exchange is available. If your Tunit is the same then you should check with your local distributor also before attempting to install. The Tunit may look the same but in many cases the harness and the program will be different.

I wish to part exchange, can I and how much will I get for old Tunit?

You should contact your closest distributor and they will offer you the best deal possible.

What does PD mean?

PD VW / Audis own new injection system. It stands for Pump deuse or single unit injection. It has proved to date a very efficient method of fuel delivery. Landrover also use this system in their TD5.

What if I have difficulty fitting the Tunit?

If you require any help at all either during fitting or even later down the line we have a free technical help line and a full after sales back up service to help you out.

What if I want more power and torque?

More power can usually be given and this can be done one of two ways. Using the manual adjustment on the tunit following your instruction manual. Laptop tuning can improve performance and this is a service provided by your local dealer. The service can help you improve performance for your specific application i.e. if you happen to tow heavy loads or drive on rough terrain. If you happen to add other performance aids such as more efficient intercoolers and injectors, then the tunit can again be reprogrammed to suit your modification.

What is a Common Rail?

Common rail is one of the latest forms of delivering high pressure fuel into a diesel engine economically. Most manufacturers have their own system, hence different units are required for different vehicles.

Where can I buy a tunit?

Who do I contact if I have any questions or I think I have a problem?

You should always contact the distributor you purchased the Tunit from. They are always in the best position to help you out.

Why do I need to adjust the tunit?

The tunit does not need adjustment in most cases as each part number comes pre-programmed to your individual vehicle. However the ability to adjust the tunit is invaluable if your vehicle power output in standard is different to what it should be. If this is the case then the tunit can be adjusted up and down to reach your optimum setting. This is something a fixed map device could not do.

Why don't the manufacturers do this?

The answer is down to cost. The Tunit works to individually optimize each vehicle and engine. Every engine has different characteristics. When the manufacture receives the engine management software for a new production car, the components are bulk programmed in batches to a given tolerance and not prepared to each individual car, treating each car to an optimum and individual adjustment would increase production costs and time for the manufacturer.

Why is the Tunit better than a EPROM replacement chip, flashing, serial port retuning or a remap?

This is our most commonly asked question, and there is more than one reason why the tunit is a preferable solution. The tunit can be fitted in most cases in under 30 minutes (some 10 minutes). Installation of a EPROM replacement chip can take up to half a day and sometimes more. Flashing as it is commonly referred to, or reprogramming the manufacturer's ECU through the OBD serial port is usually quite quick however it has its limitations as explained below. The tunit can be transferred from one vehicle to the next. Alternatively it can be exchanged via our 2 year part exchange scheme or simply sold second hand once the vehicle is disposed of. Either way you save money. You would not have any of these options with a EPROM chip or flash reprogram. Both would have to stay with the vehicle when you disposed of it. The tunit has the facility to be adjusted unlike any EPROM replacement or flashing. This means that the tunit can be adjusted to the optimum setting for each and every individual vehicle. For example a 90 bhp engine can actually vary in standard from 80-100 bhp. This means that if an EPROM reprogram or flash reprogram suited to a standard 90bhp is used on a engine producing 100 bhp then this will cause running problems (possibly smoke too). If the same method is used on an engine producing 80 bhp then this will improve the performance but only marginally. With the tunit it does not matter if a vehicle is under performing or over performing to begin with. The manual adjustment will compensate for this and make sure you achieve optimum performance for each and every individual vehicle. This adjustment is achieved by a 9 position switch on the rear of every tunit. For even more adjustment options an authorized Tunit distributor can also reprogram the tunit via a laptop to compliment the addition of other performance aids such as exhausts and intercoolers or to help with specific driving conditions such as towing or heavy loads.

Why is the tunit better than other similar products I have seen?

The Tunit is born out of much research and hard work. It has been developed by some of the top minds in Europe today. It is more compact than most, It has adjustable tuning that most do not. It works by altering parameters pro-rata, not just turbo boost or fuel quantity as some methods of tuning may use. Our methods and designs are followed by many other companies in attempts to emulate them. Our aim is to always bring any advancement to our customers as quickly as possible, so you can be assured what you receive is always the latest technology. No rolling road set up is required. We offer a 3 year warranty and part exchange facility. Our customer service is excellent ! We promote good service and customer relations as a priority through our distributor net work. What ever the problem may be we will try our best to help.

Why will giving my vehicle more power achieve better fuel economy?

The Tunit provides more torque through the engine particularly in the low to mid range. This allows the driver to change gear more quickly even with an automatic so as a higher gear is achieved giving better fuel economy. Granted you will have to do some miles to pay for the unit but you will have some fun getting there.

Will I achieve the figures that are published?

Our published figures are generally conservative so as even the under performing or tired vehicles still achieve these figures and every body is happy. So yes.

Will it make my vehicle smoke?

If your vehicle does not smoke to start with then no. If your vehicle does already smoke then in many cases the tunit can clean up your vehicle emissions. This can happen because the programming works to increase the efficiency of the injection equipment. If you are not sure if your smoke emissions are normal then ask one of our tuning experts.

Will my vehicle run badly or be noisy?

No. Most diesel engines will run more smoothly and more quietly when the tunit is installed as a result of more efficient tuning of the injection system.

Will the tunit void my vehicle warranty?

No it can't possibly, it only affects your engine. It is often thought that if a modification such as this is fit warranty is then void. This is no more true than any other modification. The Tunit is retro fit and does not interfere with the original equipment of the vehicle. If a failure was to happen on your vehicle the Tunit can become an arguable point, in the event of a warranty claim, like any retro installed part not standard on a vehicle. To our knowledge to date, the Tunit has not been responsible for any engine or engine related failures.

Keywords: Diesel Performance, engine, Fuel Economy, Vehicle

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