Downshifting Jerking..

[goldKing]

So im ALOT better at manual with my Type R now...theres only 2 trouble spots.

1. Downshifting on flat road (havnt had to downshift on uphil yet but it will prolly jerk even more doing what im doing below)

So for example if im on 4th gear going 40 MPH and im coming to a stop and I slow down to 20 MPH and it turns green and i want to turn right...I usually shift to 2nd or 3rd...let go of the clutch slowly and then give gas...but then it jerks. It jerks backwards first and then forwards..which means im not giving enough gas?

So basically I think the problem is im not rev matching when I downshift? I thought its bad to give gas when I have the clutch pressed down?

2. Changing gears from complete stop to 3rd gear on Uphill causes jerking..

So basically when im fully stopped on a hill (brake hold on) and its time to go..I let go of clutch very slowly and give gas earlier than usual and im able to start going without going backwards..but then chaning gears to 2nd or 3rd always makes me jerk (forward jerk then back)...

Am I supposed to change gear at a high MPH then usual when im on flat road? Or do I let go of the clutch even more slowly compared to flat road?

Thank you for the help!!

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[.grimace]

1) you need to add gas while the clutch is pressed down. If you are at 2000rpms in 4th and throw it into second you either need to add gas to get the rpms up to where they need to be (like 4000ish just guessing) or when you release that clutch the car will do it for you aka jerkiness. It's called rev matching

2) what RPM are you shifting at on a hill? You can bog the car down and make it jerk if you shift to early especially on a hill. I like to never let it go below 1500-2000 rpms so in first especially on a hill I'd shift no lower than 2500 rpms and only go to second don't skip to 3rd at such low RPMs or under a higher load like a hill. I think that is what you're asking?

 

[tinyman392]

So im ALOT better at manual with my Type R now...theres only 2 trouble spots.

1. Downshifting on flat road (havnt had to downshift on uphil yet but it will prolly jerk even more doing what im doing below)

So for example if im on 4th gear going 40 MPH and im coming to a stop and I slow down to 20 MPH and it turns green and i want to turn right...I usually shift to 2nd or 3rd...let go of the clutch slowly and then give gas...but then it jerks. It jerks backwards first and then forwards..which means im not giving enough gas?

So basically I think the problem is im not rev matching when I downshift? I thought its bad to give gas when I have the clutch pressed down?

2. Changing gears from complete stop to 3rd gear on Uphill causes jerking..

So basically when im fully stopped on a hill (brake hold on) and its time to go..I let go of clutch very slowly and give gas earlier than usual and im able to start going without going backwards..but then chaning gears to 2nd or 3rd always makes me jerk (forward jerk then back)...

Am I supposed to change gear at a high MPH then usual when im on flat road? Or do I let go of the clutch even more slowly compared to flat road?

Thank you for the help!!

It's all about getting into the pattern of the vehicle, and it will take time. Specifically dealing with the slight rev hang of this particular vehicle and the throttle response. That said, here are some answers:

1. If you jerk back then forward, then your RPMs are too low. If you're in 4th gear and shift to 2nd, your car should auto rev match if you give it time (it's a slow rev match, just keep the clutch in). It is a good idea to figure out what RPMs you should at when down shifting. For 40 MPH, for 3rd gear, it's just above 3200 RPM (I don't know 2nd gear off the top of my head since I don't do that shift enough). So, to go from 4th to 3rd going 40 MPH, you would want to clutch in, hit the gas (to answer your other question, yes, you can hit the gas with the clutch completely in) to raise the RPM to about 3100-3200 RPM, and release the clutch pedal when it hits that RPM range. This should lead to a very smooth downshift.
2. Quick note, if you're on a hill and have the brake engaged and you clutch in all the way, select your gear (1st), then release the brake, the car will hold itself on the hill for a second or two. You can get a smooth start this way as well. Though it can be useful to not rely on this feature; up to you. As for the jerking, if you're jerking forward (then back, or just forward), then you're releasing the clutch too early; if you're jerking backward (then forward), then you're releasing the clutch too late. Timing is key with all shifting. You'll have to get the timing and pattern down, it takes time, but you'll get used to it. Edit: if going uphill, it can be helpful to keep your RPM a little higher to create both higher torque and power to help guide you up the hill and keep momentum going. When going downhill it can be useful to keep a higher RPM to use more engine braking.

 

[MutatedMango]

It's all about getting into the pattern of the vehicle, and it will take time. Specifically dealing with the slight rev hang of this particular vehicle and the throttle response. That said, here are some answers:

1. If you jerk back then forward, then your RPMs are too low. If you're in 4th gear and shift to 2nd, your car should auto rev match if you give it time (it's a slow rev match, just keep the clutch in). It is a good idea to figure out what RPMs you should at when down shifting. For 40 MPH, for 3rd gear, it's just above 3200 RPM (I don't know 2nd gear off the top of my head since I don't do that shift enough). So, to go from 4th to 3rd going 40 MPH, you would want to clutch in, hit the gas (to answer your other question, yes, you can hit the gas with the clutch completely in) to raise the RPM to about 3100-3200 RPM, and release the clutch pedal when it hits that RPM range. This should lead to a very smooth downshift.
2. Quick note, if you're on a hill and have the brake engaged and you clutch in all the way, select your gear (1st), then release the brake, the car will hold itself on the hill for a second or two. You can get a smooth start this way as well. Though it can be useful to not rely on this feature; up to you. As for the jerking, if you're jerking forward (then back, or just forward), then you're releasing the clutch too early; if you're jerking backward (then forward), then you're releasing the clutch too late. Timing is key with all shifting. You'll have to get the timing and pattern down, it takes time, but you'll get used to it. Edit: if going uphill, it can be helpful to keep your RPM a little higher to create both higher torque and power to help guide you up the hill and keep momentum going. When going downhill it can be useful to keep a higher RPM to use more engine braking.

This was super helpful thanks for this man

 

[Williams]

This is my first manual car and im struggling as well with the smooth downshift. I usually to try to stick with auto rev match as long as you downshift 2k or above it will rev match for you, but when it comes down dropping speed from 4th to 2nd really fast I don't maintain 2k+ revs and end up jerking.

 

[CTtypeR]

This is my first manual car and im struggling as well with the smooth downshift. I usually to try to stick with auto rev match as long as you downshift 2k or above it will rev match for you, but when it comes down dropping speed from 4th to 2nd really fast I don't maintain 2k+ revs and end up jerking.

if you don't want to rev match you can double clutch into 2nd from 4th. From 4th, shift to neutral, let the clutch out, give it half a second, clutch in and shift to 2nd. at that point you just need to time it right.

if you're talking about going from 4th to second to make a turn, you can just ride the clutch through the turn. it's not something you're "supposed" to do, but to drive smoothly sometimes you need to make an exception. 4th gear, clutch in, shift to 2nd but keep the clutch in, and as you're coming out of the turn, add a little gas and release the clutch

 

[CWCTR2018]

soon he will be the victim of the CTR gear crunch

 

[caspar21]

wow, reading all this amazes me. i have been driving standard for the last 30 years and forgot what all goes into it.
i just do it without thinking so much that i would not be able to break it down like these guys.
good job.

 

[tinyman392]

This is my first manual car and im struggling as well with the smooth downshift. I usually to try to stick with auto rev match as long as you downshift 2k or above it will rev match for you, but when it comes down dropping speed from 4th to 2nd really fast I don't maintain 2k+ revs and end up jerking.

If you shift from 4th to 2nd, the car should rev match if you're above 15-20-ish MPH even if you're below 2k RPM. It's a very slow rev match though, so hold in the clutch and wait for the revs to slowly increase. You can also speed up the rev match by blipping the throttle yourself as well.

 

[diakonia]

So im ALOT better at manual with my Type R now...theres only 2 trouble spots.

1. Downshifting on flat road (havnt had to downshift on uphil yet but it will prolly jerk even more doing what im doing below)

So for example if im on 4th gear going 40 MPH and im coming to a stop and I slow down to 20 MPH and it turns green and i want to turn right...I usually shift to 2nd or 3rd...let go of the clutch slowly and then give gas...but then it jerks. It jerks backwards first and then forwards..which means im not giving enough gas?

So basically I think the problem is im not rev matching when I downshift? I thought its bad to give gas when I have the clutch pressed down?

2. Changing gears from complete stop to 3rd gear on Uphill causes jerking..

So basically when im fully stopped on a hill (brake hold on) and its time to go..I let go of clutch very slowly and give gas earlier than usual and im able to start going without going backwards..but then chaning gears to 2nd or 3rd always makes me jerk (forward jerk then back)...

Am I supposed to change gear at a high MPH then usual when im on flat road? Or do I let go of the clutch even more slowly compared to flat road?

Thank you for the help!!

Make it easy on yourself and disable rev matching while you are getting the hang of down shifting.

 

[tinyman392]

Make it easy on yourself and disable rev matching while you are getting the hang of down shifting.

I'm not sure I agree with this, the reasoning is as follows:

1. If you rev match properly, the car will just hold revs which lets you know that you did indeed rev match properly.
2. If you don't provide enough gas, the car will apply gas a second time letting you know you didn't provide enough gas. It will also hold revs so you know about how much RPM you need to bring it to for that gear at that speed (look at where the revs peak).
3. If you provide too much gas you'll hear, and see, a strong drop in revs letting you know that you overcompensated on your rev match. The revs will drop and hold letting you know about how much RPM you need to bring it to for that gear at that speed (look at where the revs stop dropping drastically).

Now let's say that you drive the car as if the rev match system didn't exist (blip and release clutch when in gear) while leaving the system engaged:

1. If you rev matched properly, the only thing the car will do is hold revs, but since you're not holding the clutch in for a substantial amount of time, this feature isn't utilized. You rev matched yourself completely.
2. If you didn't provide enough gas, the car will rev a second time preventing you from lurching backward. Works as a failsafe. You release the clutch at the peak of the revs and you're off. You messed up the rev match, the car caught it and corrected it. It also gave you information regarding the fact that you did not provide enough gas (see rest of #2 above).
3. If you provided too much gas, you'll lurch forward then backward. There will be no guessing game as to whether you lurched forward then backward or backward then forward as the latter case only applies if you don't provide enough gas (the car corrects this but is also a queue to let you know you messed up). In this instance, the lurch forward lets you know you provided too much gas and overcompensated on the gas (see the rest of #3 above).

I feel like leaving the system on mitigates a lot of the guesswork as to what the driver did wrong when rev matching because the queues to what happened are distinct enough in each scenario and also provides the driver with some failsafe if they were to make a mistake (less damage to transmission).

 

[diakonia]

I'm not sure I agree with this, the reasoning is as follows:

1. If you rev match properly, the car will just hold revs which lets you know that you did indeed rev match properly.
2. If you don't provide enough gas, the car will apply gas a second time letting you know you didn't provide enough gas. It will also hold revs so you know about how much RPM you need to bring it to for that gear at that speed (look at where the revs peak).
3. If you provide too much gas you'll hear, and see, a strong drop in revs letting you know that you overcompensated on your rev match. The revs will drop and hold letting you know about how much RPM you need to bring it to for that gear at that speed (look at where the revs stop dropping drastically).

Now let's say that you drive the car as if the rev match system didn't exist (blip and release clutch when in gear) while leaving the system engaged:

1. If you rev matched properly, the only thing the car will do is hold revs, but since you're not holding the clutch in for a substantial amount of time, this feature isn't utilized. You rev matched yourself completely.
2. If you didn't provide enough gas, the car will rev a second time preventing you from lurching backward. Works as a failsafe. You release the clutch at the peak of the revs and you're off. You messed up the rev match, the car caught it and corrected it. It also gave you information regarding the fact that you did not provide enough gas (see rest of #2 above).
3. If you provided too much gas, you'll lurch forward then backward. There will be no guessing game as to whether you lurched forward then backward or backward then forward as the latter case only applies if you don't provide enough gas (the car corrects this but is also a queue to let you know you messed up). In this instance, the lurch forward lets you know you provided too much gas and overcompensated on the gas (see the rest of #3 above).

I feel like leaving the system on mitigates a lot of the guesswork as to what the driver did wrong when rev matching because the queues to what happened are distinct enough in each scenario and also provides the driver with some failsafe if they were to make a mistake (less damage to transmission).

This all sounds correct, however it looks like goldKing is still in the process of learning how to downshift so I think in his case, disabling auto rev match will help him. All the above is way too complicated at this stage... goldKing, go ahead and disable auto rev matching and see if it helps.

 

[tinyman392]

This all sounds correct, however it looks like goldKing is still in the process of learning how to downshift so I think in his case, disabling auto rev match will help him. All the above is way too complicated at this stage... goldKing, go ahead and disable auto rev matching and see if it helps.

I still disagree and would argue that keeping the rev match system on (if you're downshifting above 2k RPM) and that it gives you instant feedback that is no more complicated vs if it were off since it's the same number of things to look out for:

1. Nothing happens and it holds revs ~ smooth downshift = you did it right
2. Revs drop quickly then holds revs ~ jerk forward then back = you gave too much gas
3. Car revs once more (2 total revs) and holds revs ~ jerk backward then forward = you gave too little gas
4. Car does not hold revs (shift back into neutral immediately in this event) ~ over rev/possible blown engine = you money shifted

If a Type R driver were to want to learn how to downshift himself, I'd advise them to keep it on and practice downshifting above 2000RPM (~2500 RPM), watch for the queues and learn the sensitivity of the throttle pedal in comfort, sport, and +R mode and only to release the clutch pedal after it holds revs. This would ensure minimal (almost 0) shock sent through the transmission (or engine, see 4 above) during the learning process since the queues provided come before you release the clutch pedal vs after.

In any event, the main issue he had would probably be in this statement here which kind of has nothing to do with rev matching system anyways...

I thought its bad to give gas when I have the clutch pressed down?

That was his major issue. If he felt that it was wrong to hit the gas with the clutch pedal in, which would mean he can't rev match unless he double clutches (kind of overkill for a synchronized car). He should hit the gas pedal with the clutch pedal completely depressed if he wants to rev match himself.

That being said, he hasn't posted in this thread since he started it in January, I'm assuming he figured it out.

 

[CWCTR2018]

wow, reading all this amazes me. i have been driving standard for the last 30 years and forgot what all goes into it.
i just do it without thinking so much that i would not be able to break it down like these guys.
good job.

its because they cant drive a manual

 

[CTtypeR]

This all sounds correct, however it looks like goldKing is still in the process of learning how to downshift so I think in his case, disabling auto rev match will help him. All the above is way too complicated at this stage... goldKing, go ahead and disable auto rev matching and see if it helps.

yeah I agree. I've been driving stick for 10 years and I still get a little confused as to when this car will and won't rev match for me. If I was teaching someone on this car, I'd turn it off.

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