7MT Extreme Rev Hang

[kodiakisland]

Bottom line, just learn to drive it as is, get a tune to try to make it better, or send it down the road. You want a modern MT, this is it.

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[EVH1994]

I've noticed the rev hang in my Badlands as well. I'm coming from a 3rd Gen 4Runner, so I've basically had to re-learn how to drive a manual, or at least that's how it feels. If I don't hold in the clutch for a few seconds, it's hard to make it shift smoothly. With my Toyota, I could let off the clutch instantly after going into gear, and feather the throttle to give it a smooth shift every time. That's not the case with the Bronco.

I understand that pretty much all new manuals have the rev hang. That doesn't change the fact that it's annoying.

Anyone know if installing the Ford Performance 2.3 tune would help reduce the rev hang and make it easier/quicker to shift through the gears smoothly?

 

[Boreal]

TLDR: It drives like a truck not a sports car.

You are accelerating from a stop. 1st gear. 4k RPM. You want to shift up. Clutch in. One second later, the revs have dropped to 3k. Another second, and they are at 2k. You can now shift smoothly into 2nd gear. Clutch out. On throttle.

The issue, in case it was difficult to comprehend all that, was holding in the clutch for 2 full seconds in order to shift smoothly. Yes you have to do that on all manual Ford Broncos. Yes even if you haven't noticed that in yours, it is still the case on yours.

I've had the chance to own two 7MT's and have test driven a couple others; I agree that this "Rev Hang" is a factor in each and every one. 1k rpm/second drop is on point, this scenario is similar to the '15 WRX when it was released - it had rev hang for days.

Maybe it's normal on a lot of new manual cars. The reason for it is not relevant. What difference does it make? The point is that it should not be normal, nor acceptable. That's 2 seconds that you are not sending power through the drivetrain. Basically just coasting. Every time you shift.

The common excuse used for the four bangers with Rev Hang was that the turbo was dumping in excess fuel heavy under load to maintain AFR's and Cylinder temps, this caused an issue with their EPA emissions... rightfully so. In order to be compliant they required more scavenging/EGR use, done mostly by holding the revs between shifts. This could very well be something the ECM/ECU is doing on our broncos considering the power plant design (Some other posts that you have seen might align with this theory). It sucks, yes. Go and get a tune thrown on and what can be programmed out, will be.

When you are trying to accelerate from a red light this can be quite annoying to other drivers behind you who observe you start to go when the light is green, and then once you reach about 15mph and begin to shift up, they perceive that you are no longer accelerating.

Who cares, you are ahead with the right of way. Accelerate as you want to.. If you didn't want people to judge your 0-60 you should've got the 10AT. However, there is more to the story than just ECU programming and emissions. Consider the Trans Synchros, Gear ratios and your personal driving style.

Our Gear Ratios
C: 6.588
1: 4.283
2: 2.365
3: 1.453
4: 1.000
5: 0.776
6: 0.646

First is twice as tall as second, Second is ~63% taller than third. This gap between the ratios means that the engine is required to drop revs far more substantially than when you are able to rip/row through them in 3/4/5 - which are much closer in ratio. Not only do we have to wait for the revs to drop to clutch without lurching, but we also require that extra second for the synchros to align... First is forever, second is slick, but three four five are pretty quick.

You've got a handful of things going against you. The OEM tune needs to use the EGR to hit EPA targets. If we scamper off the line throwing 10-15PSI at er each shift there is extra fuel being dumped in that needs to be cleared... and if you ride boost right up until to the shift point, the heavy flywheel Ford threw on, which helps prevent stalling on the trail, keeps that rotational mass of the crank spinning a lot longer. There might even be some consideration from FoMoCo on the (de)spooling of the turbo.

Again though, our opinions on the rev hang are legit, and I agree that it’s a tad excessive in first and second. But the intended design and use of this rig needs to be considered. Others may say just grip it and rip it.. all the best to you, your clutch and your synchros. Adjust your style for this Modern Manual DIT beast.

These posts follow the train of thought. Choo Choo

If I go faster they aren't as smooth, I've mentioned some other threads my trans seems to "heavily gated"
As I let the clutch out on the upshift I'm rolling back into throttle as I always have with a manual.

I've noticed the rev hang in my Badlands as well. I'm coming from a 3rd Gen 4Runner, so I've basically had to re-learn how to drive a manual, or at least that's how it feels. If I don't hold in the clutch for a few seconds, it's hard to make it shift smoothly. With my Toyota, I could let off the clutch instantly after going into gear, and feather the throttle to give it a smooth shift every time. That's not the case with the Bronco.

I understand that pretty much all new manuals have the rev hang. That doesn't change the fact that it's annoying.

Anyone know if installing the Ford Performance 2.3 tune would help reduce the rev hang and make it easier/quicker to shift through the gears smoothly?

 

[Brnzbronc]

Here's a scenario for those having difficulty understanding:

You are accelerating from a stop. 1st gear. 4k RPM. You want to shift up. Clutch in. One second later, the revs have dropped to 3k. Another second, and they are at 2k. You can now shift smoothly into 2nd gear. Clutch out. On throttle.

The issue, in case it was difficult to comprehend all that, was holding in the clutch for 2 full seconds in order to shift smoothly. Yes you have to do that on all manual Ford Broncos. Yes even if you haven't noticed that in yours, it is still the case on yours.

Maybe it's normal on a lot of new manual cars. The reason for it is not relevant. What difference does it make? The point is that it should not be normal, nor acceptable. That's 2 seconds that you are not sending power through the drivetrain. Basically just coasting. Every time you shift.

When you are trying to accelerate from a red light this can be quite annoying to other drivers behind you who observe you start to go when the light is green, and then once you reach about 15mph and begin to shift up, they perceive that you are no longer accelerating.

I'm pretty sure I've explained all this several times in this thread but I guess some people can't wrap their head around it.

Do do you have the 4:70 gears on your badlands and stock sized tires?

 

[rtazz17]

op,this is a off road vehicle not a porshe . Seems like you want a sports car. How fast you get off the line etc. Its made for a purpose which is off road.

 

[bigblueboing]

I have the 2.3 tune and I shift as fast as possible and there’s no rough shift or acceleration. The time that it takes for the revs to drop is exactly rev hang. So you have no issue.

 

[bigblueboing]

When I taught my teenagers how to drive I told them you don’t need to wait for the revs to drop just shift and smoothly release the clutch. Also you sound like a hazard on the road if you are waiting 2 seconds to shift and people behind you are honking at you.

 

[bronco100]

When I taught my teenagers how to drive I told them you don’t need to wait for the revs to drop just shift and smoothly release the clutch. Also you sound like a hazard on the road if you are waiting 2 seconds to shift and people behind you are honking at you.

You are wearing the clutch prematurely. And yes I'm always a hazard on the road

 

[bronco100]

Thanks for the info @Boreal and everyone else.

I'm going to get the 2.3L Ford performance tune and see if that improves things. If it doesn't make much difference, I'll get a lightweight flywheel as well. Will report back here and let y'all know how it goes.

 

[bigblueboing]

Thanks for the info @Boreal and everyone else.

I'm going to get the 2.3L Ford performance tune and see if that improves things. If it doesn't make much difference, I'll get a lightweight flywheel as well. Will report back here and let y'all know how it goes.

I have the tune and it doesn’t eliminate the rev hang. Like I and others have said you have to unlock the ecu to eliminate it and violate the emissions regulations

 

[Boreal]

Thanks for the info @Boreal and everyone else.

I'm going to get the 2.3L Ford performance tune and see if that improves things. If it doesn't make much difference, I'll get a lightweight flywheel as well. Will report back here and let y'all know how it goes.

The Ford Performance tune still is required to follow emissions to some degree because it’s developed by a large OEM. In the JDM world Cobb(Cobb AP) and Opensource tunes reign king and others like AEM show up occasionally. These aftermarket companies don’t follow any EPA rules even if you have to (smog tests or what not, idk, I live up north). Perhaps the JB4 Tuner is worth something… or that panda module? I’m not to sure since I am not considering a tune personally, but I’m sure the forums can help you out - even if 7/10 posts/posters don’t have much clue as to what they are spewin

Best of luck. When Subarus started with tuning, we physically added piggyback boards onto the ECU, eventually evolving to a full ECU swap, which was succeeded by OBD port methods. You’ll figure it out in time, not to worry.

 

[Lakelife36]

I took a 2hr road trip after reading this thread and paid more attention to my shift timing. In general under acceleration I took a little over a second to shift, and in that time my revs dropped a little over 1k. It works out well when you're accelerating to drop you from the mid 3ks to the low 2ks during upshift. I didn't feel a problem with rev hang before and still don't.

 

[gwp]

After further research..!

First of all: idles at 800-1200. Seems pretty high to me.

Second of all, and this is quite astounding to me: Clutch out in first gear while I’m giving it no gas does not stall the car. In fact the car just starts moving. This means it must be getting some throttle input without me doing anything right?
Anyone else with a MT that can test that? It definitely should stall right??

I believe the 7MT Bronco has a feature which pops the throttle a bit for you when taking off in first to help prevent stalling. It’s very noticeable (and cool) in 4L.

 

[gwp]

My 2.3L with the manual seems to have a lot of rev hang. Let's say I'm in 2nd gear at 3k RPM and I want to shift up to 3rd. If I shift to 3rd quickly it will jolt and jump the revs down to about 2k. So ideally I'd want to wait and let the revs drop before clutching out. Problem is it legit takes about 4 seconds for the revs to drop by 1k RPM. So to rev match perfectly, say I'm at 3k rpm, I have to clutch in, hold clutch in for at least 3 seconds, revs will now be at about 2k rpm, shift, clutch out. That's the only way it will shift smoothly. And no I'm not flat foot shifting.

What's weird is I don't really see anyone mentioning it on this forum, and I watched some POV driving videos on Youtube of the same car and didn't notice any issue with it.

Is there some way to drive/shift to reduce rev hang? My stick shift driving experience mainly comes from a 20 year old BMW track car so it's probably quite different, it has a lightweight flywheel, upgraded clutch, etc. With that car, by the time it takes me to shift (half a second or so) the revs have already dropped enough to rev match perfectly.

Maybe I'm shifting incorrectly on the Bronco? Is there some trick to it? Or is my vehicle the only one that has this issue? If I let the clutch out slower obviously I can reduce this problem somewhat, but then wouldn't I be riding the clutch and increasing wear? Has anyone had this issue?

Many modern MT vehicles have rev hang to help reduce emissions. It’s horrible on recent turbo BMWs. Having said that I don’t notice any rev hang on my 22 MT BL. Suspect you have something amiss with yours.

 

[bronco100]

Many modern MT vehicles have rev hang to help reduce emissions. It’s horrible on recent turbo BMWs. Having said that I don’t notice any rev hang on my 22 MT BL. Suspect you have something amiss with yours.

Remember, just because you don’t notice it doesn’t mean it’s not there. Are you saying that when you clutch in, the revs instantly drop by several thousand?

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