Hello everyone my question Is that in the last three months while at a red light twice I have jumped off the line thinking I was in automatic when actually I was in manual and I over reved 1gear I would say between 6500-7000rpm when I felt the engine lose power and the rpms go down or maybe I just let off.I cant really be sure because you freak out thinking ohh $$it I blew the engine.So I ask does my automatic touring have a Rev-limiter or fuel ct-offand is this what they are designed for.Thank you in advance people.

 

Rev limiter when hit cuts the fuel... (so both)

Dont worry about it...

I go in manual auto all the time... I ride 4000 rpms.... and when racing shift at 7000+ (not 6600)

One time it shifted at 8000 with out the limiter going off... (dont know why but I was watching the revs)

I dont like the limiter, because I feel the gears have higher power at those higher rpms... (at least 2nd and 3rd)

 

Please note that it is very important to understand the differences between fuel cutoff and a rev-limiter. The Z, nor any other car, has a fuel cutoff for limiting the revs of the engine. Instead, when you hit the redline, the Z's throttle body shuts down slowly to get you back within the black. This is very important to understand. Anyone who knows what engine detonation can do will understand why a fuel cutoff would be so dangerous. Cutting the fuel will lean the mix and cause detonation. Detonation causes blown gaskets, rings, cylinders, rods, etc. For obvious reasons, the throttle body is closed and the fuel is not cut.

 

Many Many Many cars have a fuel cut as part of the revlimiter. ( Cobra being one, "SVT" It did it in steps, it would start pulling some at 7250. Then after that, even more.) Some cars from the factory never expect to be FI'ed so why would they care if they are pulling of fuel out?

And yes it is a very bad thing to have happen with a FI car. Untill somone that has been "inside" a 350Z's computer, and knows it head to toe.... I don't think it's a good idea to take anyones word on how the RPM is limited. I am sure that cutting fuel isn't the ONLY way it happens (so don't flame me) But it could be PART of what happens.

So please "Techno" are you out there? Have you all even gotten into that area of the computer?

EA

 

Rx,Pep and svt thanks for helping me get a grasp on the rev-limiter.

 

The Z has a drive by wire system (electrically controlled throttle) so it can close to limit power for several puropses: traction control, rev limiting, stability control (VDC). This feature is available on only a few engines right now but will be common place soon. So MOST engines do indeed use a combination of fuel and spark cut out for those functions since your foot is mechanically controlling the throttle valve. This does absolutely no harm to the engine but it sounds terrible, like the engine has a terrible miss because it does. Most companies try to program this so it comes on gradually, retard the spark first then progressively increase the number of cylinders cut off. It can be really dangerous for the engine to cut power like a brick wall if your in the middle of a fast corner. Can you say overstear?

 

Thanx Dr Gallup