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I thought that the red line was the maximum continuous power. That is the max speed you can safely hold the engine to for continuous long term operation. On the smart 6000 rpm is the fastest the engine can turn for longterm continuous operation, but you can momentarily rev up to 6500 without doing any harm to your engine. Just don't hold it at 6500!
On my 2006 Buell XB12Ss, they denote the lower limit with yellow, which denotes the long-term operating limits. The redline is the upper limit which can be touched upon briefly.
<snip>you wish to risk your engine by exceeding redline, feel free to. It's your car.
You get, at best, partial credit for that answer.
On some drive-by-wire systems, the ECU closes the throttle butterflies as the engine approaches redline. That is because just cutting fuel can cause some engines to run "over lean" resulting in combustion that breaks piston ring lands, eventually destroying the engine (see Subara WRX STi "Service Program Campaign WVE15" for one such example).
On other systems, the ECU manipulates the spark (ignition) timing in order to implement a rev limiter, retarding it, or cutting it all together. In some cases, there is a "soft-limit" in which the engine employs a skip-fire technique where some cylinders fire and others do not. This stresses an engine and transmission less than cutting fuel, resulting loading and unloading the drivetrain as spark kicks in and out near redline.
There are other techniques employed, including limiting boost, opening wastegates, and the like. These are often done in conjunction with one or more of the above.
If you want to learn more about ECUs, I'd be happy to teach you about them. I've built comm interfaces to them, remapped the FI, changed spark timing tables, soft rev limits, hard rev limits, cooling system fan cut-on/off points, startup enrichment, acceleration enrichment, etc.
The smart, in manual, uses the shift to the next gear method. You can't overev a smart. Can't even accidentally shift to too low of a gear at speed, like some cars. The ECU won't let you.
The smart, in manual, uses the shift to the next gear method. You can't overev a smart. Can't even accidentally shift to too low of a gear at speed, like some cars. The ECU won't let you.
During the shift, the smart controls the throttle or cuts fuel (feels like the former). Otherwise, the engine would over-rev when the clutch was disengaged.
But I'm still wondering what the actual redline is: The tach shows a redline of 6000 RPM but the transmission will hold gears until 6500 RPM (according to the smart tach). smart does not appear to publish a numeric redline and professional reviews publish redlines of 6000 and 6500, with Road & Track publishing a redline of 6000 and a "limiter" of 6500.
I hope that you're right about the ECU preventing engine-damaging revs, but I'd feel better if the factory would provide a bit more information and confirmation of that.
...I hope that you're right about the ECU preventing engine-damaging revs...
It may not prevent engine-damaging revs but the two ECUs working together prevent the engine from going over what they believe to be the limit. Other manual transmission cars will let you downshift and mechanically over-rev the engine but that can't happen either.
If you put the car in manual 1st and hold it to the floor. it'll shift by itself after a few rev-limiting stutters.
Steven from the One-Lap says if you shift just before the stutter, that's the fastest. I believe him because he got instant feed-back with timing equipment and a lot of practice.
What the numbers are makes little difference because it just won't go there.
It looks like you got an actual published figure. From smart, I assume. I somehow failed to find that one.
The responses I've seen here make me feel better given the few occasions where I left a light forgetting I had switched into manual mode (Polk speakers are nice, but they can lead one to miss the engine sounds). While it may have touched redline, I know it didn't exceed it. That's a good thing. Now if only they would learn to mark their tachometers correctly...
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