ECU Upgrade

Following a lead from Jarle in Norway, I started to investigate Kronenburg Management Systems as an option for upgrading the engine management system on my Ghibli to overcome the limitations of the OEM system installed by Maserati.

The Magnetti Marelli system installed by Maserati is very old compared with today's technology. To put it into context, this system was installed in Ford Sierra Cosworth cars back in the late eighties and early ninetees. The clock speed for this system is around 4MHz. Compare this to a modern laptop or desktop computer, which runs with a clock speed an order of magnitude quicker at 4GHz. In fact, you'd be luck to find a microprocessor that runs less than a hundred times quicker than that utilised in the OEM engine management system.

The effect of this is that the engine management system currently installed in my Ghibli makes significantly less decisions per second than the systems installed on typical modern street cars. Things happen and change very quickly in a car engine, particularly when it's reving at 7000rpm. That's over 100 revolutions of the crank every second, which is 25 detonations per second per cylinder.

The way an engine management system works is by taking a snapshot of the engine, which means recording the values of certain engine parameters at a moment in time by reading the output signals being sent from the various sensors located around the engine. The key sensors on the Ghibli are the inlet air temperature and the inlet air pressure for example. In order for the engine management to make decisions, it needs some reference data. This reference data comes in the form of look-up tables, which is just how people used to make complicated calculations in the days before electronic calculators. These are called maps.

A 2 dimensional map allows you to look up an answer if you know two numbers. Let's say that the inlet temperature is listed across the top row of the look-up table and the inlet pressure is listed along the left column of the table, the answer can be found by drawing a line down from the top inlet temperature value and a line across from the left inlet pressure value. Where the two lines cross is where the answer lies.

The answer tells the engine management system to perform a certain task. However, this answer is only applicable to the moment in time when the two input values were recorded, so if the system is too slow, by the time it carries out the response, it will no longer be applicable... a delayed response.

If there are more sensors, then the management system needs more look-up tables in order to know what decision to make, which takes more time. Also, the decision may require more than one response... for example the amount of fuel that is required and the time at which to ignite the fuel may need to be adjusted. Each additional response takes additional time.

My point here is that the quicker the management system can make decisions and respond, the more effective it is. In the Ghibli, it's obvious that the speed of the engine management system is not optimal, simply by virtue of the fact that TWO management systems are required, one to control the amount of fuel being injected and one to control when the fuel is ignited. So even when the Ghibli was being manufactured, it seems to have been recognised that processing speed was a limiting factor. Therefore, increasing processing speed should have a significant effect on the performance of the engine.

The next issue with the OEM management system is its lack of diagnostic capability. The only real way of determining if the system is making the right decisions is by measuring the performance of the engine, either by having a feel for the car or by sitting it on a dyno. The system does not have an easy way of monitoring what decisions are being made, except by taking the car to a specialist who can tap into the system and monitor what it is doing, which requires a degree of skill, technical knowledge and the appropriate equipment.

Modern management systems however offer a convenient way of monitoring what is happening. They generally have a convenient port into which you can plug a computer and with special software, you can record and review what decisions are being made.

Finally, if you recognise that sub-optimal decisions are being made, you need to be able to change the decision making process, which generally means altering the look-up tables or maps. Again, on the OEM management system, this is not a trivial thing to do and requires removal of the system and some special hardware to reprogramme the memory chips on which the data is stored. Also, the way this data is stored is not very user friendly, as it is stored in a way that is convenient for the microprocessor to read and not the car owner.

The beauty of a modern system is that all these things are possible. With modern software, you programme the data in a form that is easy to understand (using decimal numbers instead of hexidecimal or even binary code required for older systems) using a laptop computer. You can also record data from the engine, review it at a leisurely pace, determine what changes you want to make, update the look-up tables and see straight away the results... without having to go to a chip-tuner!

So, after contacting Van Kronenburg and discovering that they're a Dutch firm (much to my delight, since it means that they're local), I was a bit downheartened that I never heard back from them and it is then that I ordered the PLX Devices R-500 datalogger. However, I subsequently received an email from Buddy at Wereld Auto who informed me that he had been forwarded my enquiry from Van Kronenburg. Buddy is located pretty close to where I live (about a half hour drive) and can install and setup the KMS system on my Ghibli.


Above is a picture of the hardware which would replace the two OEM ECUs. He's given me a quote for fitting the system and I'm going to see if I can integrate the PLX R-500 into the installation to give me realtime feedback on the road. I've a feeling that the lambda probe that came with the R-500 is the same as that utilised by the KMS (a Bosch wideband probe) and I'll also see if I can integrate the Exhaust Gas Temperature (EGT) probe into the KMS, with maybe some feedback to prevent the exhaust gasses getting too hot and damaging the turbos.

The KMS can also control boost pressure, although I'm uncertain if it can tie into the TurboSmart solenoid valve. This would unfortunately make my E-Boost redundant, but I think the KMS would offer greater control over boost pressure with the added advantage of being able to tie in boost pressure maps with fueling and engine load.

I'm waiting to hear back from Buddy with answers to a couple more questions that I have, but if the price is right then I think I might go along with this option. The KMS is certainly much cheaper than MoTec and I like the idea of it being local, since if it stops working then I can go 'round the manufacturer personally to get them to sort it out!

Also, Buddy appears to have worked on a number of Maseratis, including a Ghibli fitted with a V8 engine from a Quatroporte in which the owner wanted the KMS system fitting. He also told me something interesting about the intercoolers from a Golf Mk4 TDi...