Rev Limiter?
 

Is there a rev limiter on the 370Z? I'm just wondering because the needle goes towards redline so quickly in 1st and 2nd gears that I may be shifting earlier than I need to, worrying about taking the engine past redline.

All cars have rev limiter.

Yes, it has a rev limiter. It's still better if you work on your shifting so you don't bang the needle into it all the time.

Not my 911. A friend blew it up by shifting from 4th to 1st instead of 4th to 5th. I've always been concerned about not going past redline since that incident.

So what is the optimal RPM for shifting? Does it vary from gear to gear? I have the automatic transmission, if that matters.

It depends on how you drive. If you're just going to the grocery store, there's no need to take it to redline before every shift. I've never driven a 370Z, but I would assume 3,000-3,500 would be a good place to shift for everyday driving.

Yeah, usually around 4k or so for regular driving is where I'm at. I'm just wondering about the few times I decide to floor it.

A rev limiter is a computer controlled operation. However, downshifting to a lower gear beyond redline is a mechanical operation. It is physically impossible for the cpu to spin the engine down. It can cut fuel. It can cut the spark. But that's about all.

Yeah, I'm not really worried about downshifting; as sport mode automatically shifts down as you come to a standstill (for general stop and go Los Angeles traffic, this is awesome), I only downshift when I'm doing canyon cruising and I pay really close attention to the RPM before I do so.

I'm more concerned with shifting while accelerating. Now that I know I'm not going to drag the engine to 9k, I can pay more attention to shifting based on the feel of the car instead of having my eyes glued to the tach.

By the way, the 911 that my friend blew up was a 1971, so there wasn't an onboard computer... not that it would have helped if you can't control the revs on a downshift.

t-ray is completely right. The best a computer would do to save the engine would be to completely shut it down.. but even that would cause the engine to spin while not igniting any material, and inertial weight of the engine parts not being propelled by combustion would likely break several things in the connection from engine to tranny to differential.

The Z has a rev limiter. It's interesting, since if you're barely moving or stopped, the car limits revs at around 4.5k to 5k RPM. At speed, you should be able to break that limit, but you'll still bounce off the 7.5k line. I normally shift at 3.5k to 4.5k, and if I feel like hitting it a little, I keep it at or below 6k. If you really want to short shift and save a little gas, you can hit shifts at 2.5k or 3k.

So is there any advantage at all to taking the engine to redline when accelerating? For those of you who track the car, what are your shift points when trying to get the best 0 to 60?

The engine doesn't produce any more power past 332 horsepower at the engine at 7000 RPM, and at 6000, it produces about 310 or so at the engine. If you really wanted to take maximum horsepower shifts, you'd have to shift around 6500 or so. Constantly bouncing around and near 7000 RPM is going to roast your engine. I think that the maximum wheel horsepower on stock is around 290 rwhp at 7000 RPM.
Conversely, the engine produces peak torque of 270 ft-lbs at 5200 RPM.

Cool, this is what I needed!

I know that constantly redlining is very bad for the engine, but it's really that bad to go to 7k vs 6.5k? I honestly don't get many chances to floor the car; I rarely go above 80mph in Los Angeles traffic. On a good day, I might get one or two instances where there is a short stretch to gun it, and I'll only do this if the car is sufficiently warmed up (200-220 degrees), so realistically, even getting to 7k is going to be a fairly rare occurance, but if it's that bad for the engine, I can limit it to 6.5k.

Just have fun but don't beat on the engine just because you can, regardless of whether or not it's broken in.

On the contrary, I'm pretty anal about the car. I literally granny it until it hits 180-200 degrees; I know I have people behind me say, "Why is this guy doing 30 mph in a 370Z?" I just think it would be a shame to have a car like this and never have some fun with it;).

Thanks for the advice... it's been very helpful!

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.

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.

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.

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.

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

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

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

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.