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Old 04-24-2020, 07:39 PM   #1
Jdmx13b
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Default How to solve your Crappy feeling rev hang shifts

Believe it or not the car is waiting on you to shift not the other way around. With that being said try this accelerate in 1st till it’s time to go to second (any rpm of your choice) now clutch in, release the accelerator completely, get into gear as quickly as possible without being unnecessarily rough on the shifter, release the clutch faster than you normally would WITHOUT ANY accelerator input. You’ll notice that the car doesn’t jerk and you get a clean perfectly rev matched up shift also the revs exactly where they need to be instantly.

The problem Isn’t the car it was you the whole time. While the rev hang is primarily in place for emissions constraints, Subaru cleverly implemented a system to counter act it entirely granted you figured out how to do it. It also calculates exactly what rpm you’d need to be at during once the upshift was initiated. Go ahead and try it and report back! So glad I found out about this and alleviated a lot of frustration. Hopefully we can put the rev hang debate to bed now for a lot of y’all.
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Old 04-25-2020, 10:17 AM   #2
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I'm no pro, but I tend to agree. I drive the WRX like every other stick shift car I've ever had for the past 54 years.
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Old 04-25-2020, 12:22 PM   #3
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You're dead on. Saw someone on Facebook say this and its true. The quicker I shift the smoother to an extent
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Old 04-25-2020, 01:05 PM   #4
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This is kind of true, but Subaru’s still aren’t smooth shifting machines compared to Honda’s and Porsche’s.

If you need a detailed write up explaining how to do something differently to get a smooth shift, there’s room for improvement.

I’ve found the smoothest 1-2 shift comes at 14 mph. I never really had any issues getting into the other gears smoothly, but that 1-2 took some time to get right.

My first car was a manual Honda, so I was spoiled.
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Old 04-25-2020, 05:36 PM   #5
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Actually I think the rev hang helps shifting smoothly. When cars don't have that, you have to pre-gas so the engine does not go into engine braking when you let of the clutch. With revhang, you feel a smoother transition.
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Old 04-25-2020, 06:38 PM   #6
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Quote:
Originally Posted by adam99 View Post
You're dead on. Saw someone on Facebook say this and its true. The quicker I shift the smoother to an extent
Yeah man luke kraven is the man, im not even sure where he found that info, the only reason I waited this long to post here was to test it out for week to make sure It wasn't bs, I was pleasantly surprised that it actually works just as described super smooth and I’ve got to the point where I’d say it does a better job than I can at getting a smooth jerk free shift on top of that im sure this greatly reduces clutch wear!
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Old 04-26-2020, 12:46 AM   #7
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Does this work even with a Cobb ap?
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Old 04-26-2020, 11:28 AM   #8
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Quote:
Originally Posted by Jdmx13b View Post
Yeah man luke kraven is the man, im not even sure where he found that info, the only reason I waited this long to post here was to test it out for week to make sure It wasn't bs, I was pleasantly surprised that it actually works just as described super smooth and I've got to the point where I'd say it does a better job than I can at getting a smooth jerk free shift on top of that im sure this greatly reduces clutch wear!
I told him I would try it out not believing him but he was right. Second time hes helped me out now
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Old 04-26-2020, 08:06 PM   #9
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Originally Posted by jusongchoi View Post
Does this work even with a Cobb ap?
No idea, I still haven’t installed my ap (waiting on a few more bolt ons, and a large host of suspension mods). I’d imagine that it would still work depending if the parameters are tied directly to the rev hang itself. From what I’ve seen the Cobb ots maps still have rev hang tho reduced significantly so it’s possible the system is still in place for the car to calculate the exact rpm needed for the up shift. It won’t hurt to try! The way you’ll know if you’ve done it correctly is to look at your tachometer, you’ll see the revs drop instantly despite the car not bucking or jerking and remember no throttle input of any kind until you have completed the shift entirely.
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Old 04-27-2020, 10:28 AM   #10
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I wrote about this in another thread but I feel like this apparent rev hang, even after tunes, has more to do with the engine's overall conservation of momentum. Maybe there's less internal friction to slow the engine down after power is removed. I'd be curious to see if a lighter flywheel or if those lightweight pulleys actually do anything measurable. Maybe the EJ25 has more of this internal friction and maybe the FA20 as a whole is way more efficient in that regard. My tuner of choice insists that there is nothing in the software that should hold the throttle open after taking my foot off the pedal aka rev hang.
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Old 04-27-2020, 01:19 PM   #11
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Originally Posted by Mike1Juliet View Post
I wrote about this in another thread but I feel like this apparent rev hang, even after tunes, has more to do with the engine's overall conservation of momentum. Maybe there's less internal friction to slow the engine down after power is removed. I'd be curious to see if a lighter flywheel or if those lightweight pulleys actually do anything measurable. Maybe the EJ25 has more of this internal friction and maybe the FA20 as a whole is way more efficient in that regard. My tuner of choice insists that there is nothing in the software that should hold the throttle open after taking my foot off the pedal aka rev hang.
It could be possible that the rev hang is fake meaning the rev hang you see on the tach isn’t actually representative of the engines real rpm when the clutch is initially engaged. This seems to be the case to fool epa regulations. Who knows. I just don’t really understand what’s happening if it is real rev hang, and why it doesn’t cause some type of chatter or jerking when shifting using this method.
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Old 04-28-2020, 12:59 AM   #12
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Quote:
Originally Posted by Jdmx13b View Post
It could be possible that the rev hang is fake meaning the rev hang you see on the tach isn’t actually representative of the engines real rpm when the clutch is initially engaged. This seems to be the case to fool epa regulations. Who knows. I just don’t really understand what’s happening if it is real rev hang, and why it doesn’t cause some type of chatter or jerking when shifting using this method.
It is hanging. You can hear the engine note not dropping as fast as revving in neutral.
I find it pretty smooth when shifting fast.
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Old 04-28-2020, 06:26 PM   #13
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I flashed it 4k miles ago... hardly remember how shift hang feel like. Not sure if anyone notice the STI also have rev hangs but only with downshiftings. Dope as ****.
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Old 04-29-2020, 10:54 AM   #14
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Quote:
Originally Posted by jasonwrx86 View Post
It is hanging. You can hear the engine note not dropping as fast as revving in neutral.
I find it pretty smooth when shifting fast.
How has no one identified the cause if this is truly a software bound phenomena? Surely someone could find out what part of the software causes the intermittent hanging and remove it, zero it out, or what ever. right?
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Old 04-29-2020, 02:28 PM   #15
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Can confirm, if I shift fast from first to second the rev hang is almost non-existent.

Now I have to retrain my brain on my first to second shifts.
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Old 04-29-2020, 03:14 PM   #16
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Quote:
Originally Posted by Mike1Juliet View Post
How has no one identified the cause if this is truly a software bound phenomena? Surely someone could find out what part of the software causes the intermittent hanging and remove it, zero it out, or what ever. right?
Because it actually makes a smooth shift.
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Old 04-29-2020, 03:58 PM   #17
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Quote:
Originally Posted by jasonwrx86 View Post
Because it actually makes a smooth shift.
I would argue that intermittent rev hang does not equal a smooth shift let alone a good shift. I mean its one thing that people have been complaining about for years.
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Old 04-29-2020, 05:36 PM   #18
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Originally Posted by Mike1Juliet View Post
I would argue that intermittent rev hang does not equal a smooth shift let alone a good shift. I mean its one thing that people have been complaining about for years.
Using the method explained nullifies the the rev hang, it was just recently found that it even exists on the wrx, in general it makes for a faster smoother shift with less overall effort. You’re essentially shifting as if you were at wot somewhat banging gears.
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Old 01-26-2021, 11:45 PM   #19
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Originally Posted by Jdmx13b View Post
Yeah man luke kraven is the man, im not even sure where he found that info, the only reason I waited this long to post here was to test it out for week to make sure It wasn't bs, I was pleasantly surprised that it actually works just as described super smooth and I’ve got to the point where I’d say it does a better job than I can at getting a smooth jerk free shift on top of that im sure this greatly reduces clutch wear!
Link to this luke kraven or facebook board? need more info
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Old 01-27-2021, 06:46 AM   #20
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Quote:
Originally Posted by Jdmx13b View Post
Believe it or not the car is waiting on you to shift not the other way around. With that being said try this accelerate in 1st till it's time to go to second (any rpm of your choice) now clutch in, release the accelerator completely, get into gear as quickly as possible without being unnecessarily rough on the shifter, release the clutch faster than you normally would WITHOUT ANY accelerator input. You'll notice that the car doesn't jerk and you get a clean perfectly rev matched up shift also the revs exactly where they need to be instantly.

The problem Isn't the car it was you the whole time. While the rev hang is primarily in place for emissions constraints, Subaru cleverly implemented a system to counter act it entirely granted you figured out how to do it. It also calculates exactly what rpm you'd need to be at during once the upshift was initiated. Go ahead and try it and report back! So glad I found out about this and alleviated a lot of frustration. Hopefully we can put the rev hang debate to bed now for a lot of y'all.
lol they didn't implement no damn "system".

plot twist this guy works at subaru corporate and they're trying to make us think rev hang isnt a problem.

clutch still being released at higher rpms than it needs to be, thus...

it puts more wear on the syncros than preferrable..

clutch has to be released when revs are already matched..

that's how I was taught..

Last edited by basyager; 01-27-2021 at 06:52 AM.
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Old 01-27-2021, 05:31 PM   #21
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Ehhh... not really. You're just sacrificing clutch and synchro to drag the flywheel back down faster. Who the heck is applying throttle on a 1-2 normal slow shift anyways? Throttle always comes in after it's in 2nd gear and clutch fully engaged if you're doing it right. Get a Stage 1 tune to get a linear throttle and shift like a normal person and you'll be much happier.
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Old 01-28-2021, 06:21 PM   #22
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I haven't tuned my 2016 WRX yet (which I heard can get rid of the rev-hang) and I hate rough shifting. I usually use this technique when I have a passenger in the car and it works.

I have figured a technique by which I start getting going in first, and get up to like 10mph, but never fully engage first (i.e. slip it a little- nothing crazy, no high rpms) and then push in the clutch pedal and go to 2nd. If you are quick on the clutch pedal between first and second you can get a pretty good result.

If I'm alone I don't really use this technique but when you have company, especially in the city, you really can cut own on the jerkiness.

Or you could just start from second, it has more than enough power.
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Old 01-28-2021, 08:51 PM   #23
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Quote:
Originally Posted by Tom24GR View Post
I haven't tuned my 2016 WRX yet (which I heard can get rid of the rev-hang) and I hate rough shifting. I usually use this technique when I have a passenger in the car and it works.

I have figured a technique by which I start getting going in first, and get up to like 10mph, but never fully engage first (i.e. slip it a little- nothing crazy, no high rpms) and then push in the clutch pedal and go to 2nd. If you are quick on the clutch pedal between first and second you can get a pretty good result.

If I'm alone I don't really use this technique but when you have company, especially in the city, you really can cut own on the jerkiness.

Or you could just start from second, it has more than enough power.
Hahahhaaha funniest **** i ever heard.. and he does this like 100 times a day hahahaha.

Cmon man, get serious and tune the car or just buy the accessport from maperformance and see what you think. You no like you sell and lose 50-100$.
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Old 01-28-2021, 08:55 PM   #24
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I forgot to say that i can not believe you are actually thinking thats good advice you are giving someone else ***55357;***56834;
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Old 01-29-2021, 12:34 AM   #25
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I remember reading this months ago and trying the technique in the OP with my 2018. It did not work for me at all. Revs would still hang and popping the clutch as described just resulted in a very jerky shift into the next gear. Stage 1 tune solved the problem. Stock tune sucks balls

Last edited by Mr. Boost; 01-29-2021 at 12:48 AM.
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