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I would like to swap a Jag XJR engine into an AC cobra replica. Is it possible to easily bypass the security? What kind of signal does the security use?
Thank You
Andrew
If you have a North American spec car, it doesn't have the immobilizer the rest of the world spec cars do. So in a way, Jaguar already bypassed the security for you. You really need the entire electrical guide if you're going to do a transplant. Look at jagrepair.com for them
I have recently purchased a beautiful black New Zealand new XJR6 done 77000km with a full service history.
I have done a lot of reading into both your brackets, and also ecu tuning, I was hoping I would be able to purchase one of these tuned ECUs from you, I intend to fit a decat sports exhaust (I understand you sell some?) And a cold air intake.
Hi Sam,
I can provide you with a remapped ECU, but you get most of the benefit of remapping from fitting one of my brackets, at a fraction of the cost, so that is what I would recommend. You don't need a remapped ECU just because you intend to reduce the exhaust back pressure by removing some of the catalysts.
I also offer exhaust manifold flanges, if you want to get your own manifold fabricated. I can also provide dxf files from which flanges can be profile cut. I'm afraid I don't offer complete exhaust system parts.
Hi Sam Early
I am slightly hijacking the thread, but I am in Napier with an XJR, converted to manual.
I want to get a set of extractors/headers made one day, and have Andy’s pipe length/diameter plans. If I could get a small number of NZ X300 owners who want a set, we could find someone to make a few sets. I have two X300s so could leave one car with an exhaust fabricator to make a set then make a jig to churn’em out. Wouldn’t be cheap, at least NZD$1500-2000 at a guess.
You need to find a good Jag mechanic in Akld - ask around.
Welcome to the madness..
I've now taken another big step forward in remapping the Sagem Lucas GEMS 6 ECUs. I've successfully reprogrammed the ECU to compensate for fitting larger flow rate fuel injectors. I've installed Bosch EV14 fuel injectors (Part number 0 280 158 279) which have a flow rate of 6.233grammes/sec at 3bar pressure. This compares to 5.125g/sec for the standard injectors. There is a constant in the ECU software that defines the injector flow rate. I've reprogrammed this constant for the new injectors. The car starts, even without adjusting the cranking pulsewidth tables, which I intend to also remap. Reading the short term fuel trims with a scan tool, the closed loop fuelling control is not having to make significant fuelling corrections, demonstrating that I have changed the appropriate piece of data in the software. Previously one of the constraints on significantly increasing the performance of this AJ16 SC engine was the flow rate of the std fuel injectors. These could only deliver enough fuel to produce about 400bhp. Now this constraint can be overcome by fitting larger fuel injectors and reprgramming the ECU to suit.
The fuel delivered at the cylinder can be increased with a different higher pressure FPR with a second FP that delivers the required pressure / volume relationship .
Modify an existing FPR part number ? Spring stretching or shimming ?
The pulse width should be adjusted automatically up to a point the maps data arrays have data for or a fudge factor ( engineering term ) in the ECU alogrythems
The issue I would see would be if the ECU had a short enough pulsewidth at idle and if the 6 injector set had close enough bench flowrates for even fuel charging for smooth idle as it would be more critical at higher pressures
The early production AJ16 N / A engine has a 110 degree opening position cam that has idle issues that would make it even more critical
There is a stamp on the PS pump adapter if swapped out
I've now taken another big step forward in remapping the Sagem Lucas GEMS 6 ECUs. I've successfully reprogrammed the ECU to compensate for fitting larger flow rate fuel injectors.
That's great news! Definitely a big step in developing the full potential of these engines
I am getting close starting my AJ16s in my 1976 XJC.
I am creating my own fuel injection With Megasquirt 3x utilizing all factory components except for 2 wideband o2 sensors and a GM map sensor. Do you think the information you have extracted could be used as a baseline for the maps I need to create? I would certainly pay for a head start!
The O2 sensors on the AJ16 engine are the different titanium based which take a reference 5.0 volt from the lucas / seiman ECU and the O2 sensor changes resistance varies with oxygen levels so the return signal back to the ECU is modified from this reference voltage
The more common O2 sensors generate their own voltage from a ground wire
There is a cheaper Bosch # 13789 connector ready equivalent commonly available other then the expensive original Denso's
Is there a technical reason why your going with ........
There is no MAP sensor on the AJ16 engine and you may have been referring to the MAF sensor and there are 2 different part numbers and not interchangeable between a normally aspirated and supercharged engines for saturation curve response reasons and the current ECU maps don't support a swap below that saturation curve region .
XJREngineer would know far more them me on the maters .
Last edited by Lady Penelope; Dec 2, 2018 at 01:09 PM.
Hi Rusty,
I could provide you with an ECU to run your engine in your 1976 XJC, but it is not possible to "extract information" from the standard ECU , because the software defines the engine load using the signal from a mass air flow sensor not a pressure sensor. I wish you luck with your project.
Great thread on the modding Jag's ECU and originally the path I was going to pursue. I'm in the process of turbo charging my 1997 AJ16 engine with a modest 6-8 lbs of boost. Instead of modding my ECU I plan on using AEM's FI/C-6 piggy back controller to intercept the crank, camshaft, TPS, MAF and fuel injector pulses. Using simple windows software the user can control engine timing and fueling under boost at any RPM. Most importantly the FI/C-6 lets the user "clamp", set voltage ranges for the MAF and O2 signal levels under boost so they appear normal to prevent the factory ECU from throwing a code. The FI/C-6 also has programmable relay outputs that could potentially be programmed to activate a water or methanol injection system.
@XJRengineer looking for exhaust manifold drawing and thought I read once you had those for sale. I have a used cylinder head for mock up and could measure to generate CAD water jet file for turbo exhaust flange but checking to see if you have something I can use.
Hi Bob,
Interesting to read that you are planning to turbocharge your AJ16 engine. Do you plan to reduce the compression ratio. If you are starting with a naturally aspirated AJ16 engine, then it has a 10.0;1 compression ratio. This is quite high, if you plan to pressure charge it. An alternative to fitting a "piggyback" controller, would be to fit the ECU, fuel injectors and MAF from an XJR6. The OEM ECU has a very effective knock control system. If you ran your boosted engine on fuel of higher than 91 pump octane, then you might get away without reducing the compression ratio.
I sell a pair of dxf files from which you can water jet profile cut a pair of exhaust manifold flanges. I sell these files for £40 for the pai. If you want to buy these files, then please can you transfer the money to my Paypal account, using the email address, andystodart@metronet.co.uk
I have a 96 XJ12, getting ready to do a powerplant make over. Either supercharged (easier, cheaper, more power) or twin turbos, with a 6 speed manual retro. Is this something that you can remap for?
Sorry, but I don't remap the V12 engine, though I did help a friend add an inter-cooler system to upgrade a twin Vortech supercharged 7 litre Lister XJS
