Oxygen sensors and lambda control

“Closed loop” refers to to the function of the system, meaning fueling is driven off of feedback from the oxygen sensor. Weather it is mathematically driven or table driven as the initial calculation for the amount of fuel needed, once we are closed loop, we are completely reliant on the data provided by the oxygen […]

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Heat, Energy, and Temperature

Defining terminology: The total of all energy in an object is its internal energy. Heat is not the energy the body contains but the energy transferred from one body to another. We can make clear distinctions between temperature, heat, and internal energy. Temperature is a measure of the average kinetic energy of the individual molecules. […]

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Launch Control, antilag, and rev limiters

rev limiters, launch control, and antilag, are all different things. Antilag is typically accomplished via combustion continuing into the exhaust manifold to spin the turbocharger, but without accelerating the engine. This can be at light part throttle or zero throttle by the driver, but the system will hang the throttle open slightly (or slightly more […]

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Differentials

The purpose of the differential is to allow two wheels to turn at different speeds while coupled to one shaft. With the two sides coupled and no speed differential possible, as in a “locked” or “spool” or “welded” differential, the drive power when turning is substantially higher as slip is required on one side or the other. […]

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Throttle Mapping on DBW cars

In modern cars, there is no longer a “throttle cable” linking the throttle pedal to the throttle bodies. Now we have a throttle pedal that is a sensor/input to the ECU, and the ECU controls the throttle bodies. This is known as “drive by wire”. This has a number of advantages. One of the biggest […]

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Vehicle Road Testing – Part 2

In part 1 of this article, we discussed the principles for gathering coast down data. There are a number of things that can be determined from that data. We can calculate the aerodynamic drag and rolling resistance components of the total drag. The large component at high speed will be aero drag. It will vary […]

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Vehicle Road Testing – Part 1

Enhancing the performance of a vehicle isn’t always limited to making more power. Often more speed can be found by using less power to push the car through the air or along the ground. The best way to evaluate the effect of a change on a car is via controlled testing. We will need to […]

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Cam Timing on the M50 based motors

Dialing in cams can be tricky and take quite a bit of dyno time. Espeically on single vanos motors where we cannot play with cam timing independently in software like on the newer DVANOS cars. Cam movement/position must be adjusted manually, which means pulling the valve cover each time. Usually, on the dyno, when doing […]

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