Much ado About Nothing has survived for over 400 hundreds years. Not surprising this thread has lasted the evening.

 

Boy, that's the last thing I'd want to tell them! If it blows, it blows--no sense letting them know in advance I'd screwed up, eh?

 

They'll know anyway. All they need to do is check the ECU.

 

What exactly does the ECU show? A rev over redline? Highest rpms reached?

 

Good Point!

 

Probably the highest RPM, I'm not sure about the MINI but with other cars it's highest RPM. There might be a limit though for example with the BMW M3 it will show the RPMs up to 8260 or something like that, not totally sure about the number.

You just have to make sure that if it blows it takes out the ECU as well.

 

OK... tried it:

4000RPM + 4th gear = 70MPH.

shifted into 3rd... 70MPH + 3rd gear = 5100 RPM.

Waaaaaaayyyyyyy below redline, transmission tolerences or rev limiter... so, I agree again = non-issue.

 

I think it tells them everything that you've done I was at the car show at BMW North with ya'll a couple days ago since you know my supercharger has been replaced under warranty they checked the key and it came up good so the service advisor said your good to go you've been good with your car and it got fixed so I'm guessing it tells them average speed, rpm, and how fast the cars been....

 

Good now we need someone to test if 7500 RPM will toast the engine to answer Robin's question.

 

Actually, inertia alone can *never* cause engine RPM to increase. Once the rev limiter removes the spark and/or fuel, the engine RPM will no longer increase - not even a little bit.

What *can* happen is that if there is a delay between when the engine reaches the limit RPM and when the limiter actually kicks in, the engine speed will continue to increase during the delay, which could carry you slightly past the limit RPM, but as soon as the spark or fuel is cut, engine acceleration stops *immediately*.

So while you're accelerating in one gear (or revving the engine in neutral), the maximum RPM you can possibly reach is the rev limit, plus a little bit more from the limiter delay. But if you downshift too far, the engine speed will go up to whatever the lower gearing demands (or until parts start to bend/break). In the case of a heinously-stupid downshift, the only thing that may save you is if your clutch or tires start slipping.

 

since the JCW Stage 1 a higher RPM limit (6500?) with the same internatls i am sure that 7000 k would not be a issue if you sliped the clutch in on time.

 

DDeb...I've grabbed too low a gear a few times. I'd bet that our reactions were similar. You immediately made a move to a higher gear, and I mean PRONTO. I've ground the gears a few times, too, due to rather sloppy clutch use while cruising the backroads. I don't think there's anything to think about here, other than to try and avoid it in the future. Don't lose sleep over it.

 

Well if it makes you feel any better, i went from 6th to 2nd, going about ~60mph. I was going for 4th, but missed

 

Now THAT'S a real owwie!

 

yeah, it was during break in period as well probabily the week after i got the car, and I was going into a pass. I think I might have reached 6k rpm. Shouldn't be too bad.

 

Not sure what MINI stores but other car makers store rpms.

 

That's incorrect. Once spark and fuel are cut off the force of the car will continue to act through the drivetrain to turn the crank at whatever speed it needs to turn to match the speed you're going in the gear you've stuck it in. The engine becomes an air pump, sucking in air and pushing it out the exhaust.

Because of the restrictiveness of the engine as a pump it will generate a good deal of braking force (which can create problems of its own), but if you shift to a low enough gear at speed it will overrev the engine.

 

If you read the rest of my post, I said the exact same thing - stupid downshifts *will* cause the engine to over-rev, and there's nothing the limiter will do to help you.

The post I was responding to said that in the case of a missed *upshift* (getting neutral by mistake), the engine could continue to accelerate *past *the rev limiter because of the "inertia" of the engine. That was the error I was correcting.

Leaving the car in one particular gear and trying to accelerate past the rev limiter, or simply revving the car in neutral will *not* cause the engine to exceed the hard RPM limit of the rev limiter.

Re-read my post. You're absolutely correct - if you're at redline in 5th and accidentally downshift to 2nd and pop the clutch, the engine will certainly over-rev, past the rev limit and all the way until parts start breaking.

 

You quoted a statement that was correct and you started your sentence with "Actually.....never...." That was wrong, IMO. I stopped reading after that sentence because you sounded wrong.

 

You were done breaking it in then . I hope your engine doesn't burn oil as it ages.

 

Well, I thought the context of my post was pretty clear, since I quoted Dirkinoff's post before adding my reply, but I guess to be explicitly clear, I should have said "the rotational inertia of the engine alone will *never* cause the RPMs to increase after the rev limiter has removed the spark and/or fuel".

If you look at Dirkinoff's post, he was claiming that if you missed an *upshift* and ended up flooring the car in neutral, that the engine RPM could continue to increase even after the rev limiter has activated, because of the inertia of the moving engine parts. That's 100% wrong, and that's the statement I was addressing in my post.

 

I am sorry... Now, I re-read the posts and you are correct.

 

Not on my S2000 :-)

 

But if we raced in an event where you cannot rev above 3500 rpm, your S2000 would not stand a chance against the MCS!

 

I am actually not wrong unless you live on another planet! The weight of the rotating mass will pass the rev limiters cut off point, it will continue to accelerate because of the weight of the rotating mass I.E. crank, flywheel, rods and pistons ETC. until the energy is expended and then it will start its decent and then bounce of the limiter. Stop and think about what you are saying "The rotating mass will immediatley lose its energy because the rev limiter kicked in and stay at that rpm, even though it was accelerating in its rotation?" There will be a brief period of time when the inertia of the rotating mass as it "spins up" will pass the rev limiter. P.S. I am glad you do not work on airplanes! Have a nice day and enjoy the flight