XJS & XJ from KWE Cars
Classic Spirit Reborn

Optimise performance with digital engine management

We’ve had the pleasure of working on this increasingly customised V12 XJS on a number of occasions. On its latest visit to our workshop, we’ve been asked to install our Digital Engine Management (DEM) system. The system will release more power, and will allow us to optimise the fuelling and ignition for other modifications, such as cold air inlets.


Modifying these engines would normally have little or no effect, unless the fuelling and ignition is re-mappable. Without specialist knowledge of the original firmware-based map and ability to re-blow vintage eproms, this is not really possible.

Our modern Omex system, however, allows for full re-mapping. This XJS was dyno-tested at just over 300bhp, prior to any modifications being carried out. Once the installation of the system has been completed, we will be able to check on the gains we’ve made.

V12 XJS engine

V12 XJS engine. View the full gallery, here

Another advantage of the modern engine management is the much-improved reliability. The old Lucas system using the AB14 ignition amplifier is prone to failure when hot, the new system ensures this is no longer an issue.

Speak to the experts

Follow the progress of this V12 XJS, and view the full image gallery, here. Alternatively, if you’d like to know more about digital engine management systems, or our full range of services, get in touch! Give us a call on 01635 30030, follow us on Twitter, and like us on Facebook.

12:50 pm KWE Cars


  1. Barry westcott-
    August 28, 2015 at 11:18 am

    Is this DEM system available for the 3.6 with LPG conversion?

  2. Chris Knowles-
    August 28, 2015 at 12:02 pm

    Hi Barry, yes indeed – we can fit the DEM to any engine though the biggest gains are to be had with the oldest engines. LPG systems have their own ECU so our DEM would only have benefits when the car is running on petrol.

  3. August 28, 2015 at 12:13 pm

    good afternoon, Chris

    I have a 1964 Jaguar Mk.2 fitted with the 3.4 litre XK engine. Is it possible to fit fuel injection in place of the original SU HD6 carbs and an electronic mapping system?

    Kind Regards

  4. Paul Siméons-
    August 28, 2015 at 2:12 pm

    Hi,what would be the price and the time needed to make this transformation on a XJS-HE from 1982?Kinds regards,paul siméons.

  5. Chris Knowles-
    September 1, 2015 at 4:55 pm

    Hi Paul, we are still refining our procedures for this but I would allow around £6000. It takes about 2 weeks in practice, including mapping, provided we have no problems with fitting the trigger wheel – each one of which needs to be machined from solid. Regards, Chris

  6. Chris Knowles-
    September 1, 2015 at 5:00 pm

    Hi Colin,
    Yes it can be done in principle. I would need to check that the later XJ6 4.2 inlet manifold with fuel injector ports would fit the 3.4 head. There’s a fair bit of plumbing to get the high pressure fuel system installed so it wouldn’t be cheap, but certainly do-able.

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