A lot of cars would do that if you don't match revs properly, like if you downshifted from 5th to 3rd while still on the brakes and not applying any throttle.
A lot of cars would do that if you don't match revs properly, like if you downshifted from 5th to 3rd while still on the brakes and not applying any throttle.
I think I read somewhere that the only reason you would need to use double-clutch is if you don't have synchronus...
well.....ease in the clutch?
You could, but then you're slipping it more as the revs rise back to the road speed, so in the interests of mechanical sympathy it's much gentler to match the revs and engage the clutch swiftly.
We can all sit on a high horse (not directed at you JJ) about safe road driving, but I'm pretty sure that most people here on a racing simulation forum will, from time to time, enjoy their driving, or maybe even drive for pleasure. There are worse things you can do with your car than change down a gear whilst braking and matching the revs as you do so.
Very true about that, but the idea that downshifting without rev matching will unsettle the car baffles me. On road speed you ain't using much revs, and even if you go from 5th to 3rd there isn't a lot of rev to catch up for the clutch.
Personally I rev matches everytime, but it's just out of habit and I have no problem with people doing the driving school thing, there's more clutch wear but it's so minimal anyway.
Personally I rev matches everytime, but it's just out of habit and I have no problem with people doing the driving school thing, there's more clutch wear but it's so minimal anyway.
People revmatching in their road car to "save the clutch" are kidding themselves. Clutches in road cars are built to withstand slipping on downshifting and revmatching won't make any noticeable difference whatsoever in the clutch wear. Sure, it may make a tiny bit of difference in the very long run, but you'll never notice it as most people never own a car long enough for the supposedly gained advantage to become apparent.
That being said, I do it myself regularly, too, just out of habit from doing it on the PC, but I'm not kidding myself that I'm saving the clutch that way
And the argument about "unsettling the car" is absolutely hilarious. Unless you're driving your car somewhat near the limit there is no way that downshifting without revmatching will "unsettle" the car. Depends on what you interpret as "unsettling the car", of course. I think some people use that term too easily.
That being said, I do it myself regularly, too, just out of habit from doing it on the PC, but I'm not kidding myself that I'm saving the clutch that way
And the argument about "unsettling the car" is absolutely hilarious. Unless you're driving your car somewhat near the limit there is no way that downshifting without revmatching will "unsettle" the car. Depends on what you interpret as "unsettling the car", of course. I think some people use that term too easily.
Modern cars, yes - older cars, no. Even though they're made to do that, you'll greatly extend a clutch's life expectancy by revmatching.
Though besides that, and more importantly, revmatching provides a much smoother and more comfortable ride.
And, on top of that, you can bust the bolts holding your engine in place (but that would be very extreme, as in dump clutching from idle to 6000rpm)
The average driver's driving style will make a clutch last 100k to 150k km, even over 200k aren't that rare. Of course it's different with cars occasionally used for track days and the like, but your average road car will go through no more than 3 clutches in its entire life, with or without revmatching, simply because even if you do, the next owner might not and vice versa.
No stock engine will rip itself out of its mount and even a heavily modified engine in a stock mount will have trouble putting out enough torque to crack the bolts before the wheels spin.
Go sit in whatever car you have, drive it somewhere where it's safe to be silly, rev it to the limiter and dump the clutch. You'll waste your tyres, some fuel, you'll make a lot of noise but I can guarantee you your engine will stay right where it belongs (unless your engine mount is rusty or something, even so it'd need to be a lot of rust).
€: Maybe my clutch life expectancy is a little optimistic, but I can't be far off.
Our car is approaching 75k km, and the last owner was an elderly female, not known for mechanical sympathy. Still going strong with the original clutch, not a sign of wear on it, bites about 1/4 from the bottom and has full progression along the rest of the travel. My own car is a couple of years younger than me, and had a clutch change last year. That was its only change in its life span. I'd say 200k is very possible with a sympathetic driver
Not optimistic at all
Definitely
My girlfriend's car has ~150K km on it and the clutch is still as good as it ever was. A friend of mine has got a car with ~180K km on it and no problems there whatsoever, either.
Of course they last ages if used "normally", but lots of high rpm clutch dump starts and aggressive downshifting to low gears and high-rpm without rev-matching will negatively affect how quickly they wear out. Obviously. You only have to do it if you're making those aggressive down-changes anyway, which you shouldn't be if you can't, or for some reason won't, rev-match.
it would lurch FORWARD?
while BRAKING and DOWNSHIFTING TWO GEARS?
Does he mean you would lurch forward because you're slowing down more? Or is he completely wrong?
Maybe he is surprised by the fact that car lurches forward under braking when you additionally shift down, which shouldn't really happen unless you have a messed up shocks or dumping the clutch when doing so I guess
how can the car lurch forward (= accelerate) when braking and downshifting??!?
It can't, unless you get buttsecks'd (always wanted to say that :razz
in the process.That is, unless you slowed down more than the velocity that particular gear you're shifting down to would result in, but since we're talking about shifting without rev matching, that would have to be one hell of a weird transmission setup, a forward jerky motion in idle under braking... No, I don't see how that could happen, even if you do it completely wrong.
I think they're just misusing "lurch forward." What I think is meant is the car diving more (front suspension compressing) due to the additional engine braking added by downshifting.
Exactly. I think it's pretty obvious that what is meant is that you (ie. the driver) lurches forward due to the car slowing down harder
It was just badly phrased.i really would want to see that. while in the process of braking and downshifting, the car not only doesn't brake,but it also lurches forward?
i think it's not only not obvious, i'd say he specificaly speaks about the car
i think it's not only not obvious, i'd say he specificaly speaks about the car
When you accelerate, the car lurches backwards as its centre of gravity is moved backward. In other words, the chassis accelerates at a slower rate than the wheels, and the car seemingly tips backward on its suspension.
When you decelerate, the car lurches forward as its centre of gravity is moved forward. In other words, the chassis tends to want to continue forward while the wheels slow down and attempt to bring the car to a stop, so the car seemingly tips forward on its suspension.
Am I sensing a "lost in translation" moment here between English speakers and non-English speakers?
so the "car lurching forward" = "car's weight is shifted to the front" and "heel and toe" can fix that.
why am i feeling like there is no progress done discussing this particular tidbit?
it's my ****ing fault that i pointed it out.
also, samjh, if i were just a bit more hotheaded i could have taken that last line as an insult
why am i feeling like there is no progress done discussing this particular tidbit?
it's my ****ing fault that i pointed it out.
also, samjh, if i were just a bit more hotheaded i could have taken that last line as an insult
Yep! When the speed of the two clutch plates doesn't match (eg. engine RPM too low when you shift from 3rd to 2nd gear), the drivetrain clutch plate has to speed up the engine clutch plate, which then also slows down the drivetrain clutch plate respectively. They both influence eachother's speed, since they both have momentum.
Result: RPM goes up - drivetrain speed goes down. Engine revs - car lurches forward.
soooo... "the car lurches forward" is not very accurate, since the car does not, actually, "lurch forward".
right?
right?
"The nose dives down." How does that sound to ya?
Double clutch downshifting
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FGED GREDG RDFGDR GSFDG