I feel confused on understanding this system on
1. The difference between FI and Ride by Wire
2. how it improves the fuel efficiency when compared to the ride by wire system and conventional system.

I have gathered some data to make better understanding as below:-

I have studied that "Ride by wire", just replaces the wire from the throttle to unit (like intake manifold) (which decides the amount to open the butterfly valve).

And also, I have studied that, Fuel injector does a lot than just injecting the fuel into the engine. Like, eventhough u have given the throttle, it will sense

the oxygen content in the coming air,
oxygen content in the exhaust air (feedback loop),
lean angle (for fuel cutoff),
Throttle position sensor,
Rev limiter (for fuel cutoof, from avoiding damage to internals) Etc.
Crank position sensor
Input from ECU

and decides the amount of fuel to engine.

So, eventhough if you have given the throttle, it will consider it is "a input to the system"** and not as "the input to the system"**.

  1. So, then, what may be the use of removing the wire to the butter fly unit

  2. I also have studied that, R6, Fireblade, KTM RC 390 etc., have introduced this system. So sure, some sort of advantage will be there.

Could any of the guys help me to understand this better.

Thanks in advance.

  • 1
    I don't understand your question. What are you trying to repair? What is broken?
    – cory
    Commented Dec 5, 2016 at 14:03
  • @cory: I'm not trying to repair. I want to understand the things better. Commented Dec 5, 2016 at 14:07

1 Answer 1


The difference between FI and Ride by Wire

Fuel injection means that the flow of fuel to the engine is controlled by the ECU, as opposed to a carburetor. (of course, there's more to it than that)

Ride by wire means the butterfly is opened by an electronic motor, as opposed to a cable.

Fuel injector does a lot than just injecting the fuel into the engine

No, that's really all the injectors do. It's a fancy garden hose whose is nozzle turned off/on by the ECU.

the oxygen content in the coming air

That's the mass air flow meter and/or mass air pressure meter depending on vehicle. It only measures volume or pressure, not oxygen content. Oxygen content is determined in the exhaust by O2 sensors.

lean angle (for fuel cutoff)

I assume you mean on a motorcycle? That's a sensor, usually just called a tip-over sensor or similar. It's mechanism is similar to a kill switch, usually.

Throttle position sensor

Throttle position sensor

Rev limiter

Determined by the ECU which then stops injecting fuel either by fuel pump and/or injectors.

Crank position sensor

And/Or cam position sensor. The Crank position sensor indicates crank position to the ECU. This determines engine timing which determines the triggering of the fuel injector and spark plugs. The ECU also uses this measurement for other calculations though such as RPM, engine load, etc. (just off the top of my head)

and decides the amount of fuel to engine

The injector has a nozzle size, but the ECU determines how long the injector is open.

So, then, what may be the use of removing the wire to the butter fly unit

Throttle modulation. Twisting the throttle 50% opens the butterfly 25%, twisting it the remaining 50% opens the butterfly the remaining 75%. The old style cables throttles were mounted on a cam lobe to accomplish this, but now it can be done electronically and be tuned more finely.

Notice the shape of the cam lobe attached to the butterfly will cause the butterfly to open more gradually at lower throttle input. enter image description here

Also, smoother throttle pull.

Comfort/Sport/Race mode. The throttle modulation can change at the push of a button.

In some cases, the TPS and throttle control module are combined into one component keeping things simple.

In general though, it centralizes control to the ECU which is ideal when engineering an engine since ECU tuning doesn't require parts changes.

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