XS Injectors has a goal to change the marketplace, creating the best tested, matched and most accurate performance fuel injectors in the world. With the introduction of XS by Xspurt, we have a vision of being the “new standard” for performance injectors. This is how we test every injector that carries the XS logo.


An injector’s dynamic performance is comprised of three parts 

1. Static flow and

2. Linear operating flow

3. Its opening non-linear flow

All XS injectors are tested to the J1832 standard which is the international engineers standard to ensure consistency in reporting.

1. Testing Parameters

To make sure a test is repeatable every time, three parameters need to be tightly controlled. If any part of a test falls outside these parameters, we do not record it. It needs to be retested

Test controls

Test Control

2. Test 1 - High Flow Sweep (Linear Range)

12 different duty cycles tested from 20% to 90%
100 flow test samples taken at each one (1200 results recorded)
The average flow at each point is recorded
The line of best fit is drawn through those points to get the injector slope

Why we do this

By calculating the injector flow slope, you know how the injector behaves from idle all the way through to flat out.

By matching a set of injectors so that all of the injectors flow slopes (not just static flow)  are within 1% of each other you have a set of injectors that flow exactly the same at idle, all the way through the rev range to open throttle. This gives a nice even fuel delivery across the whole set with no surprises.

If you group injectors just on static flow rate they will all perform the same at the high end but will not be matched at the low end of the duty cycle. You will really notice this at cruise and idle.

3. Test 2 - Static Flow Rate

The static flow rate of an injector is determined by holding the injector fully open (no pulsing) and measuring the total volume dispensed over a given time.

The static flow rate is dependent on fuel pressure, the higher the pressure the higher the flow. The nominal flow rate of an injector is derived from its static flow rate at three bar pressure.

4. Test 3: Low Flow Sweep - Non-linear range

This is a very granular test and there are over 4000 flow tests recorded. Starting at very low duty cycles, we can see the exact point when fuel starts to come out of the injector and exactly how the injector flows up until the point that the flow becomes linear.

With this test we can determine the injector offset (the point where fuel starts to come out) and the break point (or Knee). The break point is when the non linear range meets the linear range and the flow becomes a lot more predictable

5. Grouping injectors into tightly matched sets

After the injectors have been through testing, we run them through an algorithm to group them into tight sets. All dynamic flow rates must be within 1% of each other, then of those groups, the deadtimes must be within 2% of each other.

You can log in at any time to see exactly how each of your injectors performed through the testing regime.


We don’t just talk about how good our testing process is, you can see all the details. When you buy a set of XS Injectors we show you every detail from each injector in your set. You can log onto the cloud server where your information is stored and view it at any time.

Information about your injector set

1. How tightly matched your set it.

Here you can see each injector in your set, its dead time (latency) and flow rate, the average for the set and the variations

Information about each injector in your set

You can click on each injector for every detail about that injectors test results:

You get to see the full flow profile of that injector
Static flow rate
High Slope
High Slope Offset
Low Slope
Low Slope Offset

Injectors XAA004’s details

Each injector goes through 3 tests so we can characterise everything about the injector. You can click on any of these 3 tests to see exactly what the pressure, temperature and voltage was when we took the flow samples.

Test 1 – Mid Flow Sweep (used to get the dynamic flow rate)

Test 2 – Static Flow Test. Injector fully open like a garden hose

Test 3 – Low Flow Sweep. Tests the non linear flow rates at very low openings

Fuel Pressure and Fuel Temperature recorded during Test 1 for injector ‘XAA004’

Voltage recorded during Test 1 for injector ‘XAA004’

Some Impressive stats

All up there are over 260,000 individual measurements recorded for every XS Injector tested

Each injector has over 6,900 injector pulses recorded and used to characterise its flow

Lifetime Warranty And Replacing An Injector

If you need to replace an injector for any reason you will still be able to keep a tightly grouped set of injectors.

The information and flow characteristics of your injector set is stored on a cloud server and we know exactly what your replacement injector needs to do to match the injectors you have in your car. We simply pick an injector that falls within 1% flow and 2% dead time of your set and it will fit seamlessly without the need for a retune.