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Anyone experience a weird issue when rev matching into 2nd sometimes?

J_Maher_AMG

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I've noticed the same thing in my R, as if the car doesn't recognize throttle inputs during certain 3-2 downshifts. Like you, just simply down shifting and not heel-toeing, however this is not my first manual. I know it's not user error, because if I focus on hitting the throttle significantly harder (I.e. Almost quickly mat the throttle to blip the revs) it never experienced this issue.

However if I attempt to use the same amount of throttle (relatively) as I would going from 4-3 for example, sometimes it will act as you describe, and not really blip whatsoever, whereas other times it will work fine. Like I said, if I purposefully hit the throttle a lot harder, the issue doesn't present itself.

I actually thought it might literally be me hitting the throttle TOO quickly, and it therefore not being able to register how much I wanted. When I hit it much harder and go deeper into the pedal travel, while still performing it in a quick manner, the issue disappears altogether.

Glad I'm not the only one noticing it lol but I don't believe it to be user error, as I would consider myself to be a very adept manual driver.
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altjx

altjx

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I've noticed the same thing in my R, as if the car doesn't recognize throttle inputs during certain 3-2 downshifts. Like you, just simply down shifting and not heel-toeing, however this is not my first manual. I know it's not user error, because if I focus on hitting the throttle significantly harder (I.e. Almost quickly mat the throttle to blip the revs) it never experienced this issue.

However if I attempt to use the same amount of throttle (relatively) as I would going from 4-3 for example, sometimes it will act as you describe, and not really blip whatsoever, whereas other times it will work fine. Like I said, if I purposefully hit the throttle a lot harder, the issue doesn't present itself.

I actually thought it might literally be me hitting the throttle TOO quickly, and it therefore not being able to register how much I wanted. When I hit it much harder and go deeper into the pedal travel, while still performing it in a quick manner, the issue disappears altogether.

Glad I'm not the only one noticing it lol but I don't believe it to be user error, as I would consider myself to be a very adept manual driver.
This!!!!!! This is EXACTLY what I'm experiencing here, lol. I'm glad someone with way more experience than me can chime in and know exactly what I'm talking about. Very very interesting. I haven't been able to capture this successfully on cam just yet, but hoping to soon. It's very weird. From 3rd to 2nd I pretty much have to do exactly that -- blip much harder and THEN downshift, because doing a normal blip and shifting simultaneously results in like the throttle blip not being registered or something.

Very weird situation, lol.
 

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I haven't noticed the situation you are describing, and I do rev match on almost every downshift, whether braking or not. I'll pay more attention and see if I notice this.

-T
 
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altjx

altjx

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I haven't noticed the situation you are describing, and I do rev match on almost every downshift, whether braking or not. I'll pay more attention and see if I notice this.

-T
Thanks man. Today I noticed it again in 3rd gear around 2500 RPMs when I was approaching a turn, I decided to downshift to 2nd ahead of time and there it was again, no throttle blip.
 

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Thanks man. Today I noticed it again in 3rd gear around 2500 RPMs when I was approaching a turn, I decided to downshift to 2nd ahead of time and there it was again, no throttle blip.
Hey altjx, how is your foot positioned when you downshift? If your entire foot is over the throttle when you try to blip you may be pushing too high on the peddle, Or you could be blipping too late as in trying to blip as you are releasing the clutch. If you can make a video of your footwork so you can see exactly what your feet are doing and when. Give it time and you will get the hang of it.
 

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altjx

altjx

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Hey altjx, how is your foot positioned when you downshift? If your entire foot is over the throttle when you try to blip you may be pushing too high on the peddle, Or you could be blipping too late as in trying to blip as you are releasing the clutch. If you can make a video of your footwork so you can see exactly what your feet are doing and when. Give it time and you will get the hang of it.
Hey man. That's the thing though. It's positioned the exact same all the time for every gear. It's just sometimes it works and sometimes it doesn't, kind of like what the other guy was saying. I'll go out and try to get video specifically of this happening
 

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Hmm, very interesting. If I don't blip, the car pretty much brakes harder the more I let out of the clutch. Conversely, blipping makes it smooth. I don't do this at every red light, but only when I know the light is about to turn green again, so I'll downshift as I approach the light and by the time the light turns green, I'm already in the appropriate gear and can just accelerate. If I know I'll be sitting for awhile, I just throw it in neutral and coast to the red light, and then brake. Is this bad practice?
Going to a stop at a red light! Just use the brakes! De-clutch when you nearly stop. And forget about trying to sound cool with throttle blips from 6th to 5th to 4th to 3rd, to 2nd to 1st. De-clutch and go to neutral before lugging the engine.

You are making this way too hard. And not recognizing the practical approach. Quite a few of us on here have the process down. You don't and you are imagining the engine has a mind of its own. Thats why we have a throttle. To control engine rpm and load
 
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altjx

altjx

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Going to a stop at a red light! Just use the brakes! De-clutch when you nearly stop. And forget about trying to sound cool with throttle blips from 6th to 5th to 4th to 3rd, to 2nd to 1st. De-clutch and go to neutral before lugging the engine.

You are making this way too hard. And not recognizing the practical approach. Quite a few of us on here have the process down. You don't and you are imagining the engine has a mind of its own. Thats why we have a throttle. To control engine rpm and load
I don't think you're understanding. I said when the light is red and it's turning green (not every red light). Even if I use the brakes to slow down at a red light and then the light turns green, then what? I still have to downshift, and would prefer to do it smoothly by rev matching. Again, is there a way to downshift without rev matching and have it smooth? If not, then what am I doing so wrong here? I'm not imagining the engine has a mind of its own and yes I do recognize the practical approach.

Nonetheless, another experienced driver here can also attest that he's experiencing the same issue. Although I appreciate the advice with how to "properly approach a stop", etc., I don't want this thread to deviate from the original issue of downshifting from 3rd to 2nd and having its throttle blip not register.
 

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I don't think you're understanding. I said when the light is red and it's turning green (not every red light). Even if I use the brakes to slow down at a red light and then the light turns green, then what? I still have to downshift, and would prefer to do it smoothly by rev matching. Again, is there a way to downshift without rev matching and have it smooth? If not, then what am I doing so wrong here? I'm not imagining the engine has a mind of its own and yes I do recognize the practical approach.

Nonetheless, another experienced driver here can also attest that he's experiencing the same issue. Although I appreciate the advice with how to "properly approach a stop", etc., I don't want this thread to deviate from the original issue of downshifting from 3rd to 2nd and having its throttle blip not register.
`well I just can't fathom that the car micro processor is randomly taking over your effort to blip throttle while down shifting steering into a corner, unless micro processor programing logic takes over because you are about to exceed stable vehicle dynamics envelope (like about to enter a spin). Just speculation on my part. Not with the manual here to read, but you might try and temporarly change settings that inhibit the stability control and carefully explore that envelope as a test only. You don't want to leave it inhibited, or you may/will end up with a whole handful of unstable motion. I don't claim to be an authority, just applying my engineering skills to try and understand the problem some of you guys seem to be having. These cars are designed to want to go in the direction you have the wheels pointed.
 
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However if I attempt to use the same amount of throttle (relatively) as I would going from 4-3 for example, sometimes it will act as you describe, and not really blip whatsoever, whereas other times it will work fine. Like I said, if I purposefully hit the throttle a lot harder, the issue doesn't present itself.

I actually thought it might literally be me hitting the throttle TOO quickly, and it therefore not being able to register how much I wanted. When I hit it much harder and go deeper into the pedal travel, while still performing it in a quick manner, the issue disappears altogether.

Glad I'm not the only one noticing it lol but I don't believe it to be user error, as I would consider myself to be a very adept manual driver.
I think your description points to this being a user-induced condition. As you say, when you blip harder the problem goes away. So it is 100% in your control to avoid the problem. The car is telling you it needs more throttle when downshifting into second. You just need to listen to what your car is telling you and obey her. :)

If you have access to am AIM system or other data logger that plugs into the OBD port, check your throttle position against the RPMs during your blip. You may not be blipping as hard as you think you are when you are slowing at a light versus downshifting to grab more power when driving and accelerating. The mind can play tricks on us. Kind of like on the race track when we think we went full throttle through the Kink at Road America or under the bridge at Road Atlanta, until we pull the data and see we had a confidence lift without realizing it.
 

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Weather should be warm enough for a drive this Sunday and I'm going to see if I could recreate it.
 

J_Maher_AMG

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I think your description points to this being a user-induced condition. As you say, when you blip harder the problem goes away. So it is 100% in your control to avoid the problem. The car is telling you it needs more throttle when downshifting into second. You just need to listen to what your car is telling you and obey her. :)

If you have access to am AIM system or other data logger that plugs into the OBD port, check your throttle position against the RPMs during your blip. You may not be blipping as hard as you think you are when you are slowing at a light versus downshifting to grab more power when driving and accelerating. The mind can play tricks on us. Kind of like on the race track when we think we went full throttle through the Kink at Road America or under the bridge at Road Atlanta, until we pull the data and see we had a confidence lift without realizing it.
That is the thing though, I blip in the exact same manner when going from 4-3 for example, and often it will work fine going from 3-2 as well. This issue only occurs maybe 15-20% of the time when downshifting into 2nd.

I honestly think it is an issue with hitting the throttle perhaps too quickly, as I tend to give very quick stabs of the throttle to blip and can rev match perfectly with ease, but sometimes it seems like it just doesn't register that I hit the throttle at all. I could understand if I wasn't giving enough throttle to properly downshift, but then it would simply not be smooth. Seeing as when this issue occurs, that the rpms do not blip at all, or if so only buy 100-200 rpms maybe, it clearly isn't user related IMO. It is not like I "thought I hit the gas pedal but really never" as such, so there is no way to mistake that. I know I hit the throttle, and I know it sometimes gives no response.

I also found that it occurs more regularly in Normal drive mode, with Sport somewhat alleviating the issue, possibly due to the more sensitive throttle mapping. In Sport mode, if I focus on blipping deeper/harder into the throttle range and slower, the issue never presents itself. So it may very well be a "user error" in regards to attempting to blip too quickly as such, but it still doesn't explain why it works fine the vast majority of the time, with only certain instances with it not working.

The only times that I have noticed it being an issue is when I am decelerating and coming to a stop or a near stop. When I am downshifting higher into the rev range to get on the power, I have never experienced this issue.
 

J_Maher_AMG

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Going to a stop at a red light! Just use the brakes! De-clutch when you nearly stop. And forget about trying to sound cool with throttle blips from 6th to 5th to 4th to 3rd, to 2nd to 1st. De-clutch and go to neutral before lugging the engine.

You are making this way too hard. And not recognizing the practical approach. Quite a few of us on here have the process down. You don't and you are imagining the engine has a mind of its own. Thats why we have a throttle. To control engine rpm and load
It isn't about trying to look cool at all. If you are in gridlock traffic, I absolutely agree with your perspective. But in light traffic/less commonly driven areas I downshift all the time. Why? Because I want to have the ability to accelerate or react immediately if the need should arise, or if an emergency maneuver is required.

He isn't imagining anything; reread the posts before jumping to the conclusion that the OP doesn't know how to operate a manual. I am an experienced adept manual driver and sometimes experience the same odd issue. Have never experienced it on any other manual transmission car I've ever driven, so no, it is not a wild imagination or user error IMO.
 

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Going to a stop at a red light! Just use the brakes! De-clutch when you nearly stop. And forget about trying to sound cool with throttle blips from 6th to 5th to 4th to 3rd, to 2nd to 1st. De-clutch and go to neutral before lugging the engine.
Crazy talk right here :crazy:

:D

-T
 

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Went for a drive yesterday and paid particular attention to the downshifts. Nothing out of the ordinary was noted. Throttle responded appropriately and rpm's rose to where they should.

I wonder why two people have this issue but not others. For ref. my car is an early build; Sept. 2015.
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