rev-match when changing down gears. ;)
Printable View
rev-match when changing down gears. ;)
Quote:
Originally Posted by norma
norma ... we not a pro like u la... sorry
Hardest part is getting out of 1st gear. Once you can do that go practice on a hill, if you can get these 2 things down you should be quite confident in driving manual. All the rest is pretty much thte same as driving auto, except when you start double clutching.
A driver that's not competant at down shifting smoothly imo, should not even attempt to rev match or heal toe LOL
Might end up ramming up some guys ass :p
I agree. At this early point, you should focus like others have said on smoothly changing through gears. When I taught one of my family members how to drive a manual, I got them to start on wide, straight roads where they could practice clutch control. Once you master how and when to release the clutch (ie what rpm's etc) then the rest is all pretty straight forward. It is just a question of then listening to your engine and shifting at the approptiate point.Quote:
Originally Posted by Q_ball
when in doubt
i pput the clutch in, rev it until its valve bouncing and let the clutch out
did i mention i lost my license recently
heheheh
nah man, its like anything, it just takes practise... its good that people have posted places where you can gain an understanding of what exactly is happening when your pressing the clutch in... when you learn to modulat the clutch and gas, youll be able to make things much smoother, it just takes time
thanks guys for all your help,so let me get this right all i have to do is let the clutch out more gently than usual and it should be a smoother transition ? also guys when your coming up to a corner to turn do you change gears much before the turn or as your going into the turn ? thx again
Basically, yes.Quote:
Originally Posted by anfz
For a smoother gear change, release the clutch slower, dont drop it.
As for when to change gears when approaching a corner, ALWAYS change BEFORE the corner.
NEVER change gears during a corner. The time u spend on the clutch basically gives u less control of the car.
thanks q ball for explaining that but theres one thing I dont understand and its this rev matching,double clutching thing.How does that work say im in 4th gear going at 80km and want to go into 2nd at like 40km,What steps are involved ?
I agree with crxer. Once you learn how the transmission works, it makes driving manual heaps easier. Also most of what I'm about to say is probably obvious to most people but I've stated the obvious to make the other parts easier to understand for the people who don't know manual. To skip all this obvious crap go the section numbered with a 2.
Basically all you need to know is that you've got engine, clutch, input shaft (gear set 1), output shaft (gear set 2), diff and wheels.
When the gearbox is in neutral you've seperated the input shaft from the output shaft. When you put it in gear the input shaft is then connected to the output shaft, the diff, then the wheels and also the weight of the car which is about a ton. So this is why you need to either have the clutch in or the gear box in neutral or both, because otherwise the starter motor is going to want move the car which is not good for the starter motor and also the fact that you might hit the car that may or may not be in front or behind you.
When you put the clutch in you've seperated the engine from the gear box. When it comes to releasing the clutch, I can't think of an example of what it's like but it's basically a really strong spring. So when the car is in gear (input shaft connected to output shaft) and the clutch first makes contact with the fly wheel, the engine isn't going to stall because there's not a lot of pressure on it but the the engine will start to lose revs because the weight of the stationary car is to much for the low amount of torque the engine is producing at low revs. So the more you let the clutch out your putting more pressure on the flywheel which is causing the engine to want to match the speed of what the clutch is connected to which is the input shaft which is then the output shaft then the diff then the wheels and the weight of the car which is to much for the engine so it stalls.
So obviously to counteract this, you give the engine a bit of throttle to stop it from stalling. The car then starts to move and you release the clutch more to speed up the transmission of power to the wheels. This may be a bit to much for the motor and it may lose revs again, so you give more throttle to speed the motor up again. Continue this till you've completely released the clutch and the car is traveling smoothly.
When changing gears you no doubt know you don't have to perform the above procedure, but I'll cover it anyway so you know why you don't have to.
Basically it's because the car is already moving and if you just release the clutch, the engine is going to match the speed of the input shaft which is connected to the output shaft then the diff then the wheels and chances are thats going to make the engine rev at a speed which is higher than stall speed unless you do something stupid like shifting at 900 rpm in first then to fifth.
2. Now that you know all that, here's my explanation of why you get that "engine compression" when down shifting which you may have worked out anyway if you read the afore mentioned lesson.
When you go from 4th to 3rd you speed up the input shaft which will spin faster because of the gear ratio. Example: You know how on a bike when you make the gears on the on the pedal end smaller, and the gears on the rear wheel end bigger, it makes you need to pedal faster. The same thing happens to the motor when you release the clutch. Now if you haven't "blipped" the throttle, the motor won't be spining at the same speed as the input shaft for two reasons. The input shaft is spinning faster than what it was when you were in fourth plus the time you had the clutch in, gave the motor time to lose revs.
So lets say when the engine is revving along at 2000 rpm, the input shaft is also spinning that fast. Now when you go from 4th to 3rd, you put the clutch in and then you shift the gear stick from 4th to 3rd. Now when you do that, the input shaft changes to a smaller gear while the output shaft changes to bigger gear which in turn causes the input shaft to go from about 2000 rpm to about 2500 rpm. Now while your doing that (and if you haven't blipped the throttle), engine revs will decrease depending on how long you have the clutch out. Now when you let the clutch out, the weight of your car is superior to your engine because the engine is almost a free spinning unit, so the 2500 rpm input shaft basically being connected to the weight of the car is going to try to make the engine match those revs. Now for that to happen the engine has to be able to spin that fast, which also means it has to be able to suck in air that fast, which is incredibly hard to do when its trying to suck it through about a 2-3 millimetre hole (this is the hole in the throttle butterfly that allows the car to idle. Without this hole, no air, no idle).
So if you want to counteract this engine braking procedure, you want to match the engine revs to the revs of the input shaft. So when you shift from 4th to 3rd give the accelerator a mild push with your right boot then let the clutch out before the engine slows down again. If you did this right the car should hardly jerk if at all when you release the clutch. This takes practice. If you can do this almost perfectly on your first try well done. The same applies to lower gears like from fourth to third, except obviously the input shaft is going to be spinning even faster than what it would be if you were doing a 4th to 3rd shift so therefore you need to give the throttle a bit of a bigger "blip".
Anyway have fun practising that, then one day you can try heel and toe (using your right foot to brake and blip the throttle at the same time). It's not neccessary to know how to heel and toe. It's more of a racing tactic but it will make your driving experience a lot smoother.
In lamans terms plz...Quote:
Originally Posted by gnx1987
HAHAHA
Ok, please keep in mind that we're helping a "noob" driver manual better! :p
You may want to make you responses a little simpler and easy to understand.
That is an excellent post gnx1987. Plus PQ points for you. To simplify what you are saying, the engine and gearbox can spin seperatly from each other. By engaging/disengaging the clutch, you are linking the engine and gearbox together so that they can spin in unisun. The trick is to match/get the right timing of when to engage the clutch and change gears so that everything spins together.Quote:
Originally Posted by gnx1987
As I (and others stated earlier) practice on flat, level ground engage the clutch and changing between first/second and neutral. Then step up to downshifting, which with practice, can be done smoothly ;).