Engine management and ECU's.

So we talked about fuel. The other thing needed for engine propulsion is spark and that's easy. The factory system uses a coil-on-plug setup. That means each cylinder has it's own spark plug and coil with no distributor. The factory system is very robust but if we need a cleaner spark there are plenty of aftermarket coil's or we can retrofit coils from another car. The coils are driven by the ECU (engine control unit).

In order to understand how important the ECU is, lets take a minute and talk about what it takes to make an engine not only run, but make tons of power.

The ECU takes inputs from the crankshaft and camshafts as well as various sensors around the engine bay to determine how much air and fuel are needed at any time. Example; when you first start your car. It's cold. The ECU reads the temperature of the air coming in and add's more fuel and raises the idle so that the engine heats up faster. You go to leave your parking spot, the ECU monitors throttle position, engine temperature, air temperature, fuel pressure and the amount of air coming in and adjusts spark and fuel to accommodate your driving. Once the engine warms up, the thermostat opens and coolant flows through the radiator. This signals the ECU to lower the fuel going in. Now your on the freeway. The ECU is monitoring engine speed, throttle position and air coming in. You stab the pedal to pass, the ECU calculates the air coming in and adds fuel to mix it to a perfect air/fuel ratio.

Oh yeah, it does all those calculations IN REAL TIME. It manages 4-8 inputs and outputs at any given time, and it's only the size of a double disc CD case.

So now that we know how complicated of a box it is, how can we make it better?

Piggy Back

If the factory ECU is does all of that, and is only "good" we need to work hard to make it better. The easiest option is to use a piggyback system and trick the ECU. By using a small collection of other black boxes we can trick the ECU into giving more air or fuel. Basically we make the ECU think it's giving us 1 part air and it's actually giving 3 parts air. This is a messy way to go about things, but it's cheap and functional. The setup would consist of a electronic boost controller to adjust turbo pressure and an electronic Air/Fuel adjustment controller. The amount of fiddling would be ridiculous. Cost wise this could run $150-300 a computer so up to $600.

Nistune

Nistune is an interesting option. We take our factory ECU and we add a circuit board that would allow us to connect a laptop and adjust air/fuel ratio templates and monitor sensors in real time. These templates are referred to as "maps" as in fuel/RPM maps. This system allows for maps to be downloaded and uploaded so we could find someone with a similar system and install their maps cutting down on setup time. The only downside is there is no Nistune dealers in our area so we would be on our own for optimizing and tweaking the maps. Nistune does not require a new ECU or any special wiring on the car's end. A Nistune licence and control software usually costs between $500-600.

Full Engine Management Solution.

Haltech. Greddy Emanage. Apexi PowerFC. These are full management systems that require a lot of rewiring. Their complicated, horribly expensive ($1200-1700) and incredibly sensitive to adjustments. However their level of adjustment makes them a must for the 500-700hp crowd. Also, requires a good shop who knows the software to really dial a car in. Way more than we need.

Why not the factory ECU? For now that's probably fine. It'll run, but if we want to get the most out of our fuel and spark and air combination we need some adjustability in the ECU. Think of it this way. On an RB25 the factory ECU will get it running smoothly at 250hp, but the exact same car with a dialed in Nistune would be 300-320hp and would have better fuel economy.

For us, with our car? The factory ECU will be fine at first and we would want to get the bugs worked out, but eventually a Nistune board is probably going to be installed. It seems like the most cost effective way to get to our goals without going full engine management.