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Discussion Starter #1
A couple facts first -

- I've driven a few different manual transmission vehicles, but my RS is the first that I've owned and driven daily.

-I've had my car for about a month (950 miles) and drive it daily.

I did a few searches but didn't find anything specific to our model vs the ST. Compared to other manual transmission vehicles I've driven (a couple trucks, WRX, Miata), the revs really hang when shifting gears with the clutch pedal pressed. For me, it is especially noticeably in 1st gear, and a bit less in 2nd, and much less in 3rd and 4th. When I lift off the throttle in 1st gear, fully depress the clutch pedal, and then move the shifter into 2nd, the revs will 'hang' and take a second or two to drop to a level necessary for a smooth shift. It doesn't seem to matter if I accelerate quickly in 1st or at a normal daily driver pace and shift when the idiot light tells me - it's almost like I'm still pressing the throttle down a bit.

It's a problem in the sense that I have to do my 1-2 shift reallllly slowly compared to what an automatic transmission would do, so I'm really slow in traffic initially. From 2-3 and 3-4 it's not as bad, but if I shift at what I would consider a reasonable speed the revs don't drop enough and get jerky shifts.

Anyone else notice this? Do I just need more experience or patience? Any tips?
 

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A couple facts first -

- I've driven a few different manual transmission vehicles, but my RS is the first that I've owned and driven daily.

-I've had my car for about a month (950 miles) and drive it daily.

I did a few searches but didn't find anything specific to our model vs the ST. Compared to other manual transmission vehicles I've driven (a couple trucks, WRX, Miata), the revs really hang when shifting gears with the clutch pedal pressed. For me, it is especially noticeably in 1st gear, and a bit less in 2nd, and much less in 3rd and 4th. When I lift off the throttle in 1st gear, fully depress the clutch pedal, and then move the shifter into 2nd, the revs will 'hang' and take a second or two to drop to a level necessary for a smooth shift. It doesn't seem to matter if I accelerate quickly in 1st or at a normal daily driver pace and shift when the idiot light tells me - it's almost like I'm still pressing the throttle down a bit.

It's a problem in the sense that I have to do my 1-2 shift reallllly slowly compared to what an automatic transmission would do, so I'm really slow in traffic initially. From 2-3 and 3-4 it's not as bad, but if I shift at what I would consider a reasonable speed the revs don't drop enough and get jerky shifts.

Anyone else notice this? Do I just need more experience or patience? Any tips?
I notice revs hanging a bit before the car warms up. Once fully warmed up all is normal.
 

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I believe its tuning function to help you shift at wide open throttle. My mustang does the same thing, honestly the smoothness just comes with time, and learning the ideal time to release the clutch. That being said ive daily driven a stick shift for 13 years and it still takes concentration to be totally smooth.
 

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This is included by design, and I believe it is supposed to be for emissions reasons, not performance. I know it felt really odd when I drove a Fiesta ST for the first time and experiencing this.


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Tbh I don't even notice it. Far from a pro at driving stick but even when trying to shift quickly and driving spiritedly I don't think I notice it.
 

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This is included by design, and I believe it is supposed to be for emissions reasons, not performance. I know it felt really odd when I drove a Fiesta ST for the first time and experiencing this.


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I never heard about emissions. All I know is that I was really pissed and glad the tune got rid of it on both my ST, and the RS.

The ST's rev-hang is WAY more intrusive.
 

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I never heard about emissions. All I know is that I was really pissed and glad the tune got rid of it on both my ST, and the RS.

The ST's rev-hang is WAY more intrusive.
I read or heard it somewhere. It could be totally inaccurate like much of the info acquired on the interweb.


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It's bad. I find it difficult to shift smoothly from 1st to 2nd without either shifting very slow or letting the clutch out very slowly.

Hopefully a tune will remove it.
 

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The rev hang on a WRX is bad without a tune. I didn't notice it as much on the RS. It is an emissions thing though read below...

"The cause of rev hang can be put down to the war on emissions. Recently, manufacturers have been intentionally implementing rev hang within ECU programming to save themselves from a potential emissions scandal. When the throttle is released and the clutch is dipped, an ECU with rev hang is programmed to leave the throttle slightly more open than usual.

This strategy is used because it was found that suddenly closing the throttle produced a sudden spike in gas pressure within the crankcase which emphasised the rate of oil vaporisation, thus adding to emissions from the engine. Also, when the throttle is suddenly shut, the fuel mixture suddenly becomes lean which creates NOx (oxides of Nitrogen) which also contributes to emissions."
 

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This is included by design, and I believe it is supposed to be for emissions reasons, not performance. I know it felt really odd when I drove a Fiesta ST for the first time and experiencing this.


Sent from my iPad using Tapatalk
It's been used for years (since at least 1971) to reduce the spike in hydrocarbons/nox when the throttle snaps shut. The RS is the worst offender I've ever driven, thankfully it goes away in a couple of minutes. Google decel valve. That was the old way of doing it.
 
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A couple facts first -

- I've driven a few different manual transmission vehicles, but my RS is the first that I've owned and driven daily.

-I've had my car for about a month (950 miles) and drive it daily.

I did a few searches but didn't find anything specific to our model vs the ST. Compared to other manual transmission vehicles I've driven (a couple trucks, WRX, Miata), the revs really hang when shifting gears with the clutch pedal pressed. For me, it is especially noticeably in 1st gear, and a bit less in 2nd, and much less in 3rd and 4th. When I lift off the throttle in 1st gear, fully depress the clutch pedal, and then move the shifter into 2nd, the revs will 'hang' and take a second or two to drop to a level necessary for a smooth shift. It doesn't seem to matter if I accelerate quickly in 1st or at a normal daily driver pace and shift when the idiot light tells me - it's almost like I'm still pressing the throttle down a bit.

It's a problem in the sense that I have to do my 1-2 shift reallllly slowly compared to what an automatic transmission would do, so I'm really slow in traffic initially. From 2-3 and 3-4 it's not as bad, but if I shift at what I would consider a reasonable speed the revs don't drop enough and get jerky shifts.

Anyone else notice this? Do I just need more experience or patience? Any tips?
Mine hangs on like a sad ex girlfriend/stalker.

It's terrible. Especially in track mode when not driving it that hard.
 

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Its definitely not just you. I believe its worse as the car hasn't fully warmed up yet, but I definitely have trouble shifting smoothly into 2nd and 3rd. Ive been daily driving WRX's for 5 years or so, and after a few weeks with the RS its still tough to have clean shifts. I feel like Im burning the clutch to negate the lurchiness :( hopefully a tune will fix what I'm experiencing
 

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It's been used for years (since at least 1971) to reduce the spike in hydrocarbons/nox when the throttle snaps shut. The RS is the worst offender I've ever driven, thankfully it goes away in a couple of minutes. Google decel valve. That was the old way of doing it.
Are you talking about Deceleration Fuel Cut Off? Aka what gets referred to ad DFCO in many tables?

Yes, it was used primarily for emissions, it keeps the catalytic converters from overheating from a rich condition when throttle closes while costing in gear. Fuel would build up in the cat, creating heat and shortening the life. I'm sure in some cases it actually caused fires.

The side benefit was increased fuel economy as MPG effectively becomes infinite while coasting.

The RS Pop's n' Burbles are there to simulate the over-run conditions of a car that doesn't use DFCO along with the rally car anti-lag sounds.

My GTA sounds GLORIOUS in tunnels on both accel and decel. I especially love hitting it in tunnels with the T-tops off. Or any time I'm under a bridge and can hear the exhaust echo off the girders. Okay, I'll admit, I love hearing it any time. Gives me that goofy grin. Specially when people give me dirty looks.
 
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Discussion Starter #16
Mine hangs on like a sad ex girlfriend/stalker.

It's terrible. Especially in track mode when not driving it that hard.

Whew, well on one hand I'm glad that this is pretty much a standard "feature" (not a bug, of course), but it is a bit annoying. Given the explanation about crankcase pressure and leaning out the fuel mixture on throttle close, is their any danger in tuning the rev hang out?
 

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I notice revs hanging a bit before the car warms up. Once fully warmed up all is normal.
Same for me. Definitely more noticeable when the car is initially cranked over and one doesn't sit idling in driveway/street/garage until car warms. Had similar happen in my ranger, 1st time it was a leaking thermostat housing, 2nd time was a bad throttle body (more to this, but that's at least what ford found as main culprit).
 

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Thanks. this is exactly why I joined the forum. Yup, mine hangs and drops to about 3,000 then slowly down to idle. I used to race a 240z and we took out the oil in the carb dampers so the revs dropped almost instantly.

I had an ST and really like the RS. No more torque steering and no more shuddering when wheels slip in the rain (I'd have to take off dynamic control in the rain.).
Only 2 complaints - it is not offered in Red and the increase volume control button on the steering wheel is too small.
 

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This seem normal to you guys? After my air filter/elbow install the rev hang has gotten substantially worse.

If it's cold and I'm in sport mode the revs will actually climb a few hundred before falling in some cases.
 

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This seem normal to you guys? After my air filter/elbow install the rev hang has gotten substantially worse.

If it's cold and I'm in sport mode the revs will actually climb a few hundred before falling in some cases.
Yep seems normal. If the car is cold mine will still rev hang like a SOB even with a tune that tries to reduce it.
 
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