[-Dan-]

Stand-Alone Management * Entire Section taken from GMC Motorsport

*For those not familiar with the term management systems, this section relates to the control of fuelling and ignition systems on modern vehicles. Management systems made their debut in the late 60s when a few vehicles had their fuelling controlled by electronic fuel injection and some year’s later crude electronic ignition systems found their way on to production vehicles. From the late 80s onwards most vehicles had partial or full modern management systems. Prior to any sort of management systems, and engines fuelling was controlled by carburetor and the ignition by distributor and contact breaker points. Both these systems were prone to the 2 problems of reliability and constant maintenance to keep performance and fuel consumption to optimum levels.

The advantage of modern management systems, for which you can read computer-controlled, means that the fuelling and ignition settings are constant for all time and cannot go out of adjustment, the system either works perfectly or does not work at all. For the majority of motorists this system is ideal as there is no maintenance or adjustments, for those who wish to improve the performance of their engine however, the lack of adjustment factor is this is the worst possible scenario. To improve the performance of any vehicle you have to make modifications,(read adjustments), so by the nature of modern vehicles with management systems, you are in conflict with their purpose.

Many tuning firms quote dramatic increases in power by various means but without altering the ECU, anyone who says they can increase the power of an engine by much more than 20% without altering the management system is either very optimistic, economical with the truth, never tested any results on a dyno or the standard management system specification was very poor.

By all means have your head ported and a better specification camshaft than standard fitted but remember the horsepower limitation will be the management system not the quality of the camshaft or cylinder head, so there is no point in fitting a race specification head and cam as you will be wasting your money. Another point worth mentioning is if you fit equipment to your car that needs more fuel than your management system can deliver, the engine will run weak causing overheating and a possible melt down. From our experience the maximum that a normal management system can handle in the way of engine modifications is a head job and 270degree, and maybe a 285degree cam; and even then you’ will probably find that the tick over and low speed running has been detrimentally affected.

So how you get large horsepower increases on an engine controlled with an ECU system? There are only two ways, one you the throw way your complete management system including the fuelling and ignition components and replace it with one of Weber’s competition kits, which reverts the system back to using carburetors along with a new electronic ignition system,(see kits in price list), or you get a programmable management system which broadly consist of two types. A unit like the DASTEK, which works in conjunction with your present system and allows, with the aid of a laptop computer, to change the fuelling and ignition parameters of your standard system but only within certain boundaries. The best unit, although more expensive, is OMEX unit, which allows all functions controlled by the ECU to be altered Which type you need depends on how far up the tuning scale you are going and also what the budget is.

These units allow the fuelling and ignition to be reprogrammed and are very good for high performance road cars when full benefits of a cam change and head job are required but no good for full competition due to limitations of what is re programmable. The main limitation to these units being that most standard management systems have a maximum revs cut out, to prevent over revving the standard engine, this function cannot be altered. There for, there is no point carrying out a conversion, particularly in respect to camshaft choice, where maximum power is going to occur at an rpm above that at which the cut out will operate. From experience, most systems with an RPM cut-out will operate very successfully up to a 285 cam. Using a DASTEK in conjunction with a head job and a 285 cam change can increase power between 20 and 40%.

Fitting a DASTEK to a the standard engine can also be of great benefit. How come I here you say? This seems to go against everything I have already said. The reason is that manufacturers designing the specification of the ECU have to take into consideration the variations between engines supposedly built to exactly the same specification. If you are building a million engines the differences between the best and the worst will be relatively wide and as you are only building one ECU to fit them all, its parameters will be less precise, than if each ECU was programmed for each engine individually, obviously no manufacturer could afford such time delays on the production line. There is one main area of the programming that has to be set well way from the ideal, this being at large throttle openings, where in order to prevent the engine running weak and possibly overheating or even worse engine destruction, they deliberately make the mixture far too rich. With any engine there are several mixture settings that can be done, relatively weak for best economy, a bit richer for maximum power, over rich for close to maximum power with some safety margin, so it is never too weak and then far too rich at which point power drops off dramatically. Naturally manufacturers not wanting any possible engine failures tend to err on the side of safety and run over rich, which obviously reduces power at the top end.

These are the reasons why is possible to find 2 totally identical cars which perform quite differently, one has all its specification in tune with ECU's parameters and the other doesn't. By fitting a DASTEK you can re-calibrate the engines fuelling and ignition parameters to exactly suit the engines and so get the most out of it that is possible. Therefore fitting a DASTEK unit should be considered as one of your first performance fitments and not one of the last as some people might think. The performance increase on a standard vehicle with the DASTEK fitted will vary as every vehicle is different, but from dyno tests most modern cars can benefit between 7 and 15% just by having the standard parameters adjusted to the engine. We have fitted many DASTEK units and everyone has given an increase after adjustment, this is not judgment, but by figures returned on our Rolling Road dyno. We are so confident that we guarantee to increase your horsepower or we do not charge you anything, but before we fit it, we do a full power test on your vehicle so that a comparison can be made after fitment. Lets assume we fit the unit and there is no power increase we will just remove the unit and you are free to go, so even assuming this situation, you will had a free power test and graph to prove it, so why not give it a try.

These systems can achieve all performance advantages of the DASTEK but is not limited in the parameters that can be changed, as it is a complete new management system to enable anything and everything to be changed. Why not add another 4 injectors or have them set sequential or not, up rev limit to 10000 RPM or perhaps decide when you sell the car to take it off and fit it to your next vehicle, as they are not model sensitive. You can fit it to any engine 2,3,4,5,6,8 or 12 cylinder. This system is so good that is the most widely used in competition motor sport today because it not only enables the engine tuner to adjust everything necessary, it is also ultra reliable.

Is not possible to quote figures for the costs of fitting either of these units other than the basics, as it depends how which you need, as there are special wiring looms, ignition triggers, relays, throttle switches, multiple throttle bodies, large injectors, ram trumpets, filters etc. so you can pick and choose the parts you to require.

CHIPS

I bet I can guess what you have been saying to yourself while reading most of this. This guy has forgotten about “CHIPS”. No I have not!

Although chips are the latest buzzword you have to appreciate what they actually are. All ECU's have a memory chip in them which records the parameters, by changing your standard chip for “performance chip” all you are doing is changing one chip with set parameters for another chip with set parameters. Knowing how even a small alteration to engine specification such as removing an air filter and replacing it with air trumpets can need quite significant changes to a program, it is impossible for anyone to write a chip in isolation and say this will give 10% more power or whatever, exactly for the reasons I mentioned earlier, that even 2 cars with supposedly the same specification will perform differently. The only time a chip could be worth even contemplating is on a set performance kit, fitted in its entirety with no deviation from the spec it was set up for. Generally this is only the case for turbo and supercharger engines where the chip is mainly altering boost pressures, not the general parameters.

There have been quite a few rolling road tests done comparing standard chips against performance chips, the results don’t make good reading, most only gained the odd horsepower which could be judged as testing error, some were even worse than standard, with the odd one showing quite a worthwhile gain. The fact that ABC company did the best chip on the test does not mean that their chip for another model would be just as good, its more likely to be down to dumb luck.

Most chips cost between £180 and £280 plus fitting or sending away your ECU for fitment at another £50, so do you think it is a chance worth taking?. Your only positive benefit might be to be able to brag in the pub that your car is chipped. Remember this when someone says his or her car has been chipped especially if you are buying it. If you are serious about more power cheaply with a guaranteed gain, get a DASTEK.

MF2 FUEL DRIVER

This unit is for adjusting the fuelling on any ECU controlled engine and all the adjustments are made by screwdriver, no lap tops or specialized equipment are needed, although highly recommended to be set on a rolling road with a gas analyzer. The problems for a lot of people, especially those living in countries where sophisticated test equipment , programmable management systems or fitting agents are not available, they are severely restricted in what modifications they can make, as no matter what specialist head,cams etc they have fitted, unless they can alter the fuelling, at the very least, the conversion is never going to work. The only downside with this unit is that it needs to operate on extra injectors fitted and cannot be used on the standard ones connected to the standard ECU. This also has a plus side in so far as your standard fuelling is not interfered with and this unit only comes in for additional fuelling requirements, most commonly it is used on supercharged and turbo charged conversions, this being the unit GMC use on all their supercharger conversions.