Rev limiter how does it work

Any engine is only designed to be able to function up to a certain speed, which we measure in revolutions of the crankshaft per minute.

One example is the valvetrain. They effectively get held open. It can cause a loss of compression, misfires, or it could even cause the valves to spring so far back that one hits a piston. Expect to be ordering fresh engine parts very shortly afterwards. By limiting its revs, either on the low end for launches or the high end for engine protection, your car is working to make the driving experience better. You'll have more fun laying down efficient launches, and even more fun keeping your engine safe and away from expensive repair bills caused by a high-rev event.

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While it would be fair to say that the average, suburban runabout would never need a two-step rev limiting system, there are many people who derive a certain amount of pleasure and satisfaction from making modifications to standard vehicles, albeit for reasons that are not always clear to many of us.

We need not delve into what might possibly motivate people to do this, but there is always a chance that you might be called upon to install a two-step rev limiting system on a modified vehicle, or perhaps to diagnose divine? Below is a quick rundown of the problems you are most likely to encounter with two-step rev limiting systems that were not installed by a professional technician-.

In addition, since two-step rev limiting systems create random misfires, some misfire detection systems may set the misfires as hard faults, which could, and often does, cause the ECU to initiate a limp mode.

Before you install a twp-step rev limiting system, do some research into whether or not the system is fully compatible with the vehicle; it could save you many hours of trouble later on. A common complaint about aftermarket two-step rev limiting systems is that excessive wheel spin occurs when the first stage rev limiter deactivates. The remedy is relatively simple; since the VSS Vehicle Speed Sensor is recalibrated during the initial setup, the initial setting may be too low.

On forced induction engines, the most common reason for this is excessive boost pressure. Remedy this by reducing the maximum first stage engine speed to reduce boost pressure. On naturally aspirated engines increase the first stage engine speed at which ignition timing retardation kicks in to a value that is closer to the maximum first stage engine speed, to reduce engine power at launch.

While this might appear to be counter-intuitive, the practical effect of increasing this setting is that the ignition timing will be retarded just before the engine develops its maximum power, which should in theory , reduce, or eliminate wheel spin.

This is most commonly caused by an incorrect fuel cut-off setting on systems that cut the fuel supply to limit engine speed. There should be no reason to worry about pumping the throttle with the engine off. Now if the ignition was in the run mode the car is on but the motor is not running then you might flood the car. Over-revving can cause damage to your valve train by causing a valve to stay open for too long.

This leads to valve float. Valve float occurs when a valve is stuck in between open and closed. This will cause an immediate loss of power.

Reduce the weigth of the rotating mass and balance everything. You have already switched to a lighter flywheel, now all you have to do is go to a lighter crank, pistons, rods, clutch assy, pulleys etc. The more money you spend, the faster it will rev. Compression Ratios have very little effect on how high an engine can relaible rev.

The reason it SEEMS higher compression means higher revs is because more intense camshafts require higher compression. A motor that delivers its power and torque proportionally higher in the rev range would be considered a rev-happy engine.