7MT Extreme Rev Hang

[bronco100]

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?

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[Denny Swift]

I think you have a problem, and I’d take it to the dealer. I may die of old age before I get my Bronco, but I did test drive a manual, and it behaved normally (not like you describe). I’ve also read a couple of professional reviews on the manual, and everyone said that the shifter and clutch are pretty darn good. Sounds like your car has a bug. Hopefully it’s an easy fix. Perhaps it’s the gas pedal (you’re effectively stepping on a rheostat) or in the throttle position sensor.

 

[bronco100]

I think you have a problem, and I’d take it to the dealer. I may die of old age before I get my Bronco, but I did test drive a manual, and it behaved normally (not like you describe). I’ve also read a couple of professional reviews on the manual, and everyone said that the shifter and clutch are pretty darn good. Sounds like your car has a bug. Hopefully it’s an easy fix. Perhaps it’s the gas pedal (you’re effectively stepping on a rheostat) or in the throttle position sensor.

One thought I had is if my floor mat could be pressing on the gas pedal. Going to check that in a bit.

 

[kodiakisland]

My Tacoma is well known for rev hang, and I had to completely relearn how to shift to get it smooth. The Bronco has nothing even noticeable compared to the Tacoma. Maybe that's because I experience bad rev hang all the time and wouldn't notice a slight rev hang, but in 2,500 miles of driving the Bronco I've yet to experience anything I would call rev hang.

Maybe something going on with your Bronco to cause that.

 

[heynow14]

If these were carbureted engines, I'd suggest a stiffer throttle return spring but...

I've got 1100mi on my Bronco and although I do wish the off-throttle response was faster (to drop rev) I too am not seeing what you're describing. Def sounds like a software issue to me.

 

[AllthePonies]

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?

I have zero rev hang with my 7MT. It does seem like something is amiss based on your experience.

I don't love how the clutch spring is so light and and that the engine is so darn quiet, but hey at least it's a manual.

Best of luck!

 

[JT58Bronc]

Rev hang sucks. I had it in my 2016 Subaru WRX. So difficult to wait for the RPM's to drop before you shift.

It sounds like it is not common on the Bronco so probably should get it checked out.

 

[bronco100]

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??

 

[ScottyScooter]

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 don't have a Bronco yet, but I do know that it does, in fact, automatically apply throttle when your taking off from a stop. I've seen this mentioned and demonstrated on a few YouTube reviews of the Bronco.

I test drove a 7 speed at the dealership before I placed my order, and there was no rev hang. From what you are describing, you definitely have an issue that needs to be looked at.

 

[bronco100]

I don't have a Bronco yet, but I do know that it does, in fact, automatically apply throttle when your taking off from a stop. I've seen this mentioned and demonstrated on a few YouTube reviews of the Bronco.

I test drove a 7 speed at the dealership before I placed my order, and there was no rev hang. From what you are describing, you definitely have an issue that needs to be looked at.

Is there a way to disable that? Also, should I drive differently knowing that feature? Should I intentionally not give it throttle when taking off from a stop? I tried doing that a couple times and it did not feel very smooth.

 

[zombie]

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??

My badlands will crawl away in 1st with no throttle application (I still have to feed the clutch pedal out)

 

[brauncoboy]

At a drive bronco event that I attended last week the instructor had to explain to me not to press the gas to get moving - we actually did it in first gear and second gear coming from a stop without pressing the gas.

 

[bronco100]

Ok I've timed it a bit, by taking some video. I've determined the revs drop almost exactly 1k per second.

In one test, I got to 45 mph in 2nd gear at 5k RPM on a level road, in Normal GOAT mode. Then, I let off the gas and fully pressed in the clutch quickly to just let the revs fall. It took 0.97s to get to 4k RPM, and then 1.1s to drop to 3k RPM, and then 1.45s to drop to 2k RPM.

This is quite different than I am used to on my old BMW, where as soon as I press in the clutch, it can go from 7k RPM down to idle in about a second.

I also noticed in one Youtube video from Redline Reviews where he does some 0-60 tests with the manual, he does not wait for the revs to drop to shift. He simply shifts quickly and the revs jump from say 5k to 2k instantly instead of falling naturally. That doesn't seem like a good idea to me but maybe that's how to shift with these vehicles.

 

[Catmandu]

At a drive bronco event that I attended last week the instructor had to explain to me not to press the gas to get moving - we actually did it in first gear and second gear coming from a stop without pressing the gas.

I can definitely get moving in first with no throttle, but no way from second.

 

[sgraing1]

A vacuum leak can cause your issue. Also, a simple ecm refresh may cure your problem.

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