Rev Limiter?

kannibul

Rev limiters work on killing spark to the cylinders, preventing the engine from powering itself above a certain number of RPM.

It does nothing to prevent someone from downshifting and slamming the engine to RPM above redline....potentially blowing the engine.

tbonesteak

Factories are very conservative about setting redline. The car theoretically could rev to 8k and wouldn't see problems unless it was left there for a very prolonged period of time. And for revving to 7.5k being very bad for the engine, where did you pull that out of? That is the most incorrect statement i've ever heard. You would cause more wear and tear by redlining the motor every time but the engine was built to withstand that. Even if you tracked your car all its life and revved it to the red, other components would start failing before the motor suffers catastrophic failure. That is if you've been doing proper maintenance.

jsnmtth

Sorry to bring up an old thread, but my mind is boggled that I have a stock rev limiter in a base model? Is that true? I can just slam the gas in first and it will make me go "bla bla bla" unless I shift?

I'm so tempted to try it, but also so scared.

filip00

The Z has two rev limiters in fact. If you're in neutral and you slam the gas, the revs will stop at 5000rpm. It's a soft limiter. If you put the transmission in gear, regardless of being stopped and having the clutch depressed or if you're accelerating, then the limiter is set at 7500rpm. If you hit that, the engine will not rev higher. That's limiters and it shouldn't worry you - if the engine oil is hot enough (i.e. 90° Celsius) then it's perfectly fine to rev it - but don't abuse it.

Someone earlier mentioned downshifting instead of upshifting. Regardless of rev limiters, if you downshift instead of upshift, your wheels are turning at the same speed, while through the transmission, you will bring those revs to the engine, and if you downshift, you will bring revs up, regardless of what the engine rev limiter is. It will most likely break the engine, as it's not design to rev so high. More in this video, if you're interested: https://www.youtube.com/watch?v=p9SbDvMhCFs

And then thirdly, the Z also has a shift light. There is a red colored light - yellow on newer models - which will start blinking when you're 500 revs below the set limit. This limit is NOT the rev limiter, but a limit that is factory set at 7000, which you can set yourself to any RPMs you'd like. So if you have a gf who drives your car and you want to limit her from driving like a maniac, you can set the shift light to 4000rpm and tell her the car will start blinking when she "must" shift and there you go. This will not affect the actual rev limiter, which is factory set at 7500. The shift light's function is to help you shift, seeing the blinking with peripheral vision, without actually strictly looking at the gauges.

Spooler

No, if you hit the rev limiter it will kill the throttle by closing the throttle bodies.

filip00

I think it cuts the fuel supply and spark, not throttle bodies.

Spooler

It depends on how bad you hit it. First step is to close throttle bodies, Next is to cut fuel and spark.

filip00

Could be for the Z. My very old bmw with cable-actuated gas pedal has a rev limiter and that one for sure couldn't do anything with the throttle bodies, the limiter was solely down to spark/fuel cutoff.