How different do TDI VE Injectors flow?cross graphic

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This is the test results of various nozzle flow rates showing the differance in deliverd quantity.

This has been done useing the most accurate testing method as all nozzles were tested useing the same "on engine" paramiters.

Please note that this information remains the property of United Diesel Fuel Injection Services Ltd.

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PD 8V Nozzles, how do they compare?cross graphic

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This is an updated PD 8V Nozzle flow comparison chart. The results are the fuel delivers from each nozzle tested in the same injector and using the same test process.

There seems to be a miss conception about flow rates and percentages, for example you will see that the Firad +80% does not flow 80% more fuel than a stock nozzle

Stock 150 Bhp Bosch OEM nozzles delivers 23.8 Cms, with the same test the Firad +80% delivers 32.2 Cms which is a 37% increase in fuel.

I believe that some manufactures use the percentage to represent a hole size measurement but they all keep the manufacturing process to them selves so we might never know. The important thing for me is the end result of what the nozzle and injector body is capable of delivering.

It is more important to measure delivery of the complete injector as it will be a true reflection of it performance in the engine.

Should you have any questions or are able to offer relevant information please contact or go to our face book page

The chart is in the file download/

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PD and VE injectors, how do you do them?cross graphic

When enquiring about injector nozzle replacement, either standard or high performance or the supply of service exchange units it is important that you deal with a company that has the experience, knowledge and equipment to do the job correctly.

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Performance injectors, my mapper wants to know what my injectors deliver.cross graphic

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We are pleased to be able to offer a custom “Injector Mapping Chart” for common rail injectors. This is especially helpful to any tuner who is in the process of remapping a modified vehicle. Whether there has been a bigger turbo, higher flowing injectors or a larger inter-cooler fitted, by being able to see what fuel deliverers are produced will allow for a more accurate and effective tune allowing for optimum performance.

The “Injector Mapping Chart” is totally custom so we can add or alter parameters to suit your needs. We are also able to compare delivers from stock and performance injectors so that the increases can be used to match other performance enhancing products.

Should you wish to know more please do not hesitate to contact us.

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Plug and Play Re-maps and Files Sold on E-bay, any Good?cross graphic

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There are a number of basic power upgrades available in a plug and play format or are downloadable from the web. Whilst some of these items can offer slight increases in power, they operate by merely adjusting a specified signal within the ECU by a set tolerance. It's impossible to compare these inferior upgrades with a full rolling road re-map which measures and adjusts hundreds of signals and data files within the ECU.

We advise that these generic files and unsupported devices for sale on the web should be avoided at all cost. We've seen too many customers come to us after a bad experience - and there was no one else to turn to either. We're always happy to advise on your tuning needs.

Should I tell my Insurance Company?cross graphic

Whilst the upgrade in many cases is undetectable, the responsible and correct answer to this question has to be "yes", your insurance company should be notified of any modifications including tuning. However, the good news is many insurance companies do not penalise you for upgrades of this nature, particularly if you're tuning for increased fuel economy.

Adrian Flux is one such company.

VE two stage injectors, how do you set them up?cross graphic

The set-up of a two stage injector is very important to get optimum performance from your vehicle. If it is not set up correctly it can restrict the mount of fuel delivered on the other hand it can dump too much fuel in causing black smoke.

The nozzle choice is also important but we will cover nozzle sizes in a differant FAQ.

The set up is all to do with NOP1 and NOP2 (nozzle opening pressure) NOP1 is easy enough to do as this can be done on a standard pop tester.

Nozzle Opening Pressure (NOP2) cannot be detected by measuring only pressure or only flow. Similarly injected delivery alone does not give an indication of NOP2.

Want to get more technical? have a look at our download.

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VW T5 hard startingcross graphic

What is a PD injector upgrade and how is the injector calibrated?cross graphic

Unit injectors incorporate the nozzle assembly and a built in high pressure pump producing injection pressure of up to 2000 Bar. Similar to that of a common rail system but with the fuel rail chamber only needing a supply pressure of 2.0 Bar.

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What is a VE injector power upgrade and how is the flow checked?cross graphic

Using the 2 Stagemaster's flow mapping ability we are able to map the flow characteristics of each nozzle prior to fitting in the injector. This test is performed on the nozzles prior to installation to insure that every nozzle performs exactly to specification. We are able to evaluate delivery rate, peak delivery volume as well as flow through the flow range.

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What is involved in tuning a Nissan Navara?cross graphic

The last 15 years have seen pickups go from workhorse to lifestyle vehicle, but the Navara has never strayed too far from its practical roots and gets pretty good reviews from the critics.

Having had a lot of experience Tuning Nissans I will be honest with our findings.

We have found that the best tune is our Performance Tune, this improves the drivability of the vehicle to no end, better acceleration, smoother drive, a lot
less gear changes when towing or going up hills. It does not improve the MPG if the vehicle is loaded or towing but there is about a 5% fuel saving when not loaded.

We fine tune to ensure that the map is bespoke, as we do not supply generic maps and guarantee that every tune is customised to suit your driving style and needs.
The gains that are achievable are,

Power Tune = 35 Bhp and 70 Nm Torque increase
With a fuel saving of 5% achievable.

Fuel savings can only be achieved with a “like for like” driving style
All tuning is insured and comes with our 30 day money back guarantee. I would also like to put your mind at rest with regards to the ECU being over written at a service or back at the main dealer, as long as you own the vehicle will re map your vehicle to your chosen tune at no extra charge.

With a JTAG tune

The Navara is challlanging to remap as it is needs "open heart surgery" to get it right. Many owners have tried a tuning box but have experianced it to be unreliable. We have had the experiance to do a remap via the open ECU with great results.


What is the Process for Nozzle Set-up and Calibration on a PD Unit Injector?cross graphic

Nozzle Set-up and Calibration, PD Unit Injectors.

Disassembly, Inspection and Nozzle Mounting for PD Injectors.

Unit injectors incorporate the nozzle assembly and a built in high pressure pump producing injection pressure of up to 2000 Bar. Similar to that of a common rail system but with the fuel “rail” chamber only needing a supply pressure of 2.0 Bar. The PD system greatly increases the precision and control over combustion when compared with older fuel injection systems. Specialist equipment is needed just to be able to strip and inspect the injectors due to the complex set up of internal locating plates and pins. With every service we provide a complete strip and inspection of the injector. Parts are then ultra sonically cleaned and worn parts replaced. A nozzle of choice is then assembled into the nozzle assembly holder and NOP1 is setup to insure the most precise calibration of the injector. We are able to set the PD injectors back to OEM specifications or, for custom or race applications, we can provide a custom pressure setup for your specifications.

Testing and Calibration.

The complete injector is then reassembled and mounted into the 555-2N Injector-Pump System Cam Box and run on our test bench connected to the 555- 24LX/EVO Simulator. The following areas of the injector are tested,

  • Effective Injection Time in ms
  • Nominal and Effective start of injection
  • Nominal and Effective end of injection
  • Current peak absorbed by the electrical solenoid and error message if value is exceeded
  • Peripheral Speed of drive shaft whilst pumping
  • Test Fluid Temperature measures at the Nozzle Outlet with a maximum protection value
  • Visualization of “0” setting for both Cam and the Rotation Mode
  • Atomization characteristics at Start Of Injection

Once the injector has passed either OEM or custom setting specifications the injector is marked with its unique identification number. A performance printout can be supplied on request. All injectors supplied will have a set of new fitment seals and the necessary washers.

What were the test conditions regarding the PD body flow tests?cross graphic

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The same DSSR 130+ nozzle was used in the 3 PD bodies. NOP 1 (nozzle opening pressure) was set to 300 Bar. The stock bodies were left as is and our standard test procedure was followed. The results have been documented as "test results for PD body flow rates"

Testing and Calibration.

The complete injector was then reassembled and mounted into the 555-2N Injector-Pump System Cam Box and run on our test bench connected to the 555- 24LX/EVO Simulator. The following areas of the injector are tested,

  1. Effective Injection Time in ms.
  2. Nominal and Effective start of injection.
  3. Nominal and Effective end of injection.
  4. Current peak absorbed by the electrical solenoid and error message if value is exceeded.
  5. Peripheral Speed of drive shaft whilst pumping.
  6. Test Fluid Temperature measures at the Nozzle Outlet with a maximum protection value.
  7. Visualization of “0” setting for both Cam and the Rotation Mode.
  8. Atomization characteristics at Start Of Injection.

Probably what will be more relavent is how we achieved the fuel specs.

Low Delivery - Cm3 Fuel delivery x 200 strokes at 300 RPM bench speed.

Full Load Delivery - Cm3 Fuel delivery x 200 strokes at 600 RPM bench speed.

Please see the attached document for the full test plan

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Why choose United Tuning?cross graphic

Having been in the motor trade for 4 generations, established in Shrewsbury since 1992, we understand the importance of quality, service and credibility this is why we have become the Shropshire agent for Viezu Technologies.

Award winning tuning services, Viezu is the UK’s only ISO certified tuning and training provider, who are are approved and used by the largest fleet and industry professionals across the world. All tuning is insured and comes with our money back promise.

Viezu tuning and ECU remapping is dyno developed, and emission tested, which is a legal requirement. All our tuning is custom and developed with years of research and development, giving you the choice of the level of tune you want. Be it performance or economy tuning, we have the ability to reach your exact requirements.

Why don't Vehicle Manufactures Tune their Vehicles?cross graphic

The most common of all tuning questions, it is not complicated, but there are a few answers to this question, some more obvious than others.

Vehicle manufactures are in a tough position here, they have to build one vehicle for all drivers, it’s a bit like a nice suit off the shelf, it fits well, its looks smart, but it can’t be custom tailored for the end customer, tuning is just the same, if you own a fleet of vans you may want a speed limiter or rev limiter added to help save your fuel, yet another customer may want a little more power to help with towing, or heavy payloads, these sort of changes can only be made once the vehicle is built and the customer needs something other than off the shelf

Fuel quality, we are often asked to tune for different fuel quality, either higher or lower, once an owner knows where his vehicle will be used and what it will be used for, we can adapt the tuning for environmental, altitude and fuel quality.

And surprisingly, many manufactures do offer ecu remapping services, any showroom these days will be full of eco tuned vehicles, often sporting a “blue” badge, just like our BlueOtimize tuning, with our tuning though, you don’t need a new vehicle to benefit from economy tuning.

In addition, many manufacturers offer power and performance tuning upgrades too, or offer the same engine in a range of vehicles offering different power levels, this enables customers a choice, taking account of tax banding, insurance, performance, price and economy, In most cases though the choice is controlled with software, just like our tuning, but with Viezu you don’t have to decide what you want from new in the showroom, we can tailor your vehicle to your needs whenever you want.

Will my Fuel Consumption go up After an Upgrade?cross graphic

No, in fact quite the opposite, even on a performance tune, if you continue to drive the car in the same way as you did before the upgrade, your fuel consumption will probably improve. Of course if you have a track map installed on the car and you are driving the car under the conditions with which a track map is intended you're likely to find a slightly reduced mpg figure.

Economy tuning can have a dramatic effect on fuel consumption, with considerable improvements being achieved along with huge money savings on fuel. All Viezu fuel economy tuning has a money back promise, if you are not delighted – you don’t pay for the tuning.

Will Re-mapping Invalidate my Car's Warranty?cross graphic

However, manufactures of course have the right to investigate and possibly reject a warranty claim if the failure is directly related too and caused by the tuning, (remember not all tuning is the same quality as Viezu) Therefor, for your total peace of mind, all Viezu tuning work is insured and guaranteed, if our tuning causes a failure inside or outside of the warranty period you are covered. It’s exactly why you should chose Viezu for all your tuning work, only Viezu dealers have this depth of cover and we will be happy to show you and talk through the Viezu tuning insurance policy. We say this with confidence because of the rigorous testing regime all ECU remapping and vehicle tuning files go through, and we even give a life-time software guarantee too for reinstallation.

Should you lose your tuning files due to dealer actions or parts failure we will be happy to re-install the map onto your car free of charge for as long as you own the vehicle.

Will the Life Span of my Engine be Reduced?cross graphic

No, not at all if you use a Viezu dealer. Sadly some engines can be over tuned, "stressing" the engine, transmission, cooling systems, brakes, etc, and reducing the life span and reliability of the car. This is why it's so important to choose the best – choose Viezu, the research and development we carry out ensures all our tuning is of the very highest standard possible.

We take great care to ensure that all of our modifications have no detrimental effect on your car. In a lot of cases the economy tune actually helps to extend the life of components such as the clutch and gearbox by making the delivery of the power far less aggressive and smoothing the overall drive of the vehicle.