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Discussion Starter #21
My unexpected find? Rust on the front lip of the hood that is apparently a huge problem with GCs and Pacificas...

I have my ipod plugged in to the USB and stashed in the little upper shelf of the under radio cubby. Perfect spot for it that still lets you use the lower section for other generic stuff.

I think the best is the tons of extra storage around the spare tire. Mine holds a 30' snatch strap with a few shackles, trailer hitch shackle mount, 10' tree saver strap, tire plug kit, AC/DC converter, and Viair compressor.
I agree with the extra storage once the cover is lifted from the spare tire area and in the cargo area in general.
I just wish these GC's would have more nooks and cranny storage areas in the driver's area.
There just too streamlined in that front cabin area.
 

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Back to "finds" – there's that little kinda sorta hidey hole at the top back of the front cubby in the console. I like that.

And back seats that recline are often a surprising and welcome "find" for passengers.
Hmmm, I'm thinking the Cigarette Lighter/Power Socket in that location, perhaps your's doesn't have one and an open space instead. Or perhaps since I have a 2011, they changed it in later years.....

Today i decided to see the seconds from 0 to 60 mph for my V6.
Enabled Sport mode and the transmission manual shift paddles.

Shifted from 1st gear at the redline which is around 6500 rpm.
To my unexpected disappointment the engine bogged from 1st to 2nd gear with a good 1+ second bog.
WTF? Is my transmission slipping from the 1st to 2nd gear?

Experimenting further on lonely country roads:
I tried shifting from 1st to 2nd at 6k rpm...same engine bog.
Tried shifting from 1st to 2nd at 5500 rpm...seemed a little better but still a little shorter engine bog.
Finally shifted from 1st to 2nd at 5k rpm....the manual shift was more or less flawless.

Think i found the probable cause.
Apparently the PCM shuts down the engine at or close to the redline rpm to prevent engine damage.
I noticed that even shifting at or a little lower than redline, the engine's inertia momentarily caused the rpm's to drift up towards redline causing an apparent momentary engine shut down.
Could be the short hesitation between gear shifts is enough for the PCM to detect an over redline condition.
With my rig it looks like manual shifting is at 5k rpm instead of redline rpm.

Is this normal?
Anyone else experience this in manual shift mode?
But it works perfectly when you let the transmission shift itself? You may be manually shifting at the wrong point.

The Rev Limiter coming on? Not likely, when you upshift to the next gear engine rpm would go down, not up, if you hit the rev limiter it would have to be before you shifted to the next higher gear. The wet clutches in an Automatic trans power shift, you don't go to neutral to rev match the gears between shifts, the wet clutch packs absorb the power of just shifting to the next gear at full power. BTW, the rev limiter shuts off the fuel injectors and/or removes ignition pulses, its usually set a few hundred rpm above the redline and won't turn the fuel/ignition back to normal a few hundred rpm below the redline, when you hit the rev limiter the engine dies and the rpm drop below redline, if you don't pull your foot off the accelerator, the engine will bang up and down, above/below the redline. Usually it will bang back and forth a couple times before you can pull your foot off the accelerator.

Shifting at redline is not always the best performance, you have to look at the gear ratios and the torque curve of the engine..... ....the torque often tapers off at higher rpm, you want to spend the most time at the peak torque rpm and a close ratio transmission like the 8 speed, the drop in rpm shifting to the next gear might not drop you back to the peak torque and with lesser torque multiplications, the engine could even bog down...

If you do a full throttle acceleration in sport mode letting the trans shift itself, pay attention at what RPM the trans shifts itself, that is likely the ideal shift points for best performance with the transmission, engine, vehicle combination.....

The ZF 9-speed FWD transaxle, used in FCA FWD or AWD extended from the FWD vehicles NOT the WK2, does have a one dog clutch instead of a wet clutch pack. That requires it to shift like a manual trans, disconnect all power, rev match, to shift then put on power. And that results in a lot of complaints from customers cause it does not feel like a normal automatic trans shift.

Yep thats totally understood!

Today i tried Sport mode in automatic shift control from a standstill with full throttle.
I'll be damned if it didn't automatically shift from 1st to 2nd at 6K rpm with a crisp shift.o_O
Before when i tried shifting manually at 6K....engine bogsville.
Could be the manual shift paddle lag time or something causing the momentary engine shut down between 1st and 2nd gear @ 6k rpm @ full throttle.
Hmm, that busts what I just said.... ....apparently 6k is the ideal shift point...
It is possible the Tach lags the actual RPM, but you should see the needle go above 6k after the shift, it lagging the rpm dropping...
What is the actual redline for the vehicle, where on the tach does it turn red?
 

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Discussion Starter #24
Hmmm, I'm thinking the Cigarette Lighter/Power Socket in that location, perhaps your's doesn't have one and an open space instead. Or perhaps since I have a 2011, they changed it in later years.....


But it works perfectly when you let the transmission shift itself? You may be manually shifting at the wrong point.

The Rev Limiter coming on? Not likely, when you upshift to the next gear engine rpm would go down, not up, if you hit the rev limiter it would have to be before you shifted to the next higher gear. The wet clutches in an Automatic trans power shift, you don't go to neutral to rev match the gears between shifts, the wet clutch packs absorb the power of just shifting to the next gear at full power. BTW, the rev limiter shuts off the fuel injectors and/or removes ignition pulses, its usually set a few hundred rpm above the redline and won't turn the fuel/ignition back to normal a few hundred rpm below the redline, when you hit the rev limiter the engine dies and the rpm drop below redline, if you don't pull your foot off the accelerator, the engine will bang up and down, above/below the redline. Usually it will bang back and forth a couple times before you can pull your foot off the accelerator.

Shifting at redline is not always the best performance, you have to look at the gear ratios and the torque curve of the engine..... ....the torque often tapers off at higher rpm, you want to spend the most time at the peak torque rpm and a close ratio transmission like the 8 speed, the drop in rpm shifting to the next gear might not drop you back to the peak torque and with lesser torque multiplications, the engine could even bog down...

If you do a full throttle acceleration in sport mode letting the trans shift itself, pay attention at what RPM the trans shifts itself, that is likely the ideal shift points for best performance with the transmission, engine, vehicle combination.....

The ZF 9-speed FWD transaxle, used in FCA FWD or AWD extended from the FWD vehicles NOT the WK2, does have a one dog clutch instead of a wet clutch pack. That requires it to shift like a manual trans, disconnect all power, rev match, to shift then put on power. And that results in a lot of complaints from customers cause it does not feel like a normal automatic trans shift.


Hmm, that busts what I just said.... ....apparently 6k is the ideal shift point...
It is possible the Tach lags the actual RPM, but you should see the needle go above 6k after the shift, it lagging the rpm dropping...
What is the actual redline for the vehicle, where on the tach does it turn red?
From my un-scientific testing, 6K rpm is where it shifts ok in auto sport mode.
5k rpm is where it will shift ok with no 1st to 2nd gear bog in manual sport mode.

Either the PCM lowers the rpm limit in manual shift mode or manually hitting the +paddle creates a PCM communication lag or similar allowing a few mili-seconds delay between gear shifts enough to skyrocket the rpms to the cut off limit.

I don't know off hand if these new GC's have a separate transmission controller aside from the PCM.
If it does that would explain the crisp auto shift from 1st to 2nd at 6k rpm where the tranny controller is doing the real time gear shifting.
On the other hand with manual shifting, the PCM could be involved to detect paddle shifter movement then relaying the shift command to the transmission controller creating enough of a delay between shifts causing the rpms to skyrocket triggering the rpm limit.
All guesses at this point.
 

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Discussion Starter #26
Thanks for that verification BubbaATL.
Now i know at WOT in auto transmission mode my Jeep flawlessly shifts @ 6K rpm like at least one other V6 out there.
Why it bogs at 6Krpm in manual shift transmission mode is still a mystery.
 

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What happens if you go full throttle in 1 and just keep your foot down and don't shift? Does the rev limiter kick in and just let you run along at 6k? Or does it still bog somehow because you're trying to give it full throttle at or beyond redline? (No, I don't want to try this for myself to find out. You do it.)
 

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I've had my GC just about a year now and when backing out of my garage like i've done dozens of times before i discovered something new today.

Namely when the Jeep is put in reverse, the side view mirrors tilt down lower to view the rear wheel area.
Put it back in drive and the mirrors tilt back up to normal driving mode.
Cool.

Probably to make sure while backing up the family dog is not behind the rear wheels or the any other obstructions.
love this feature as well..when backing into curb edged parking spots it allows getting super close and eliminates curb rash on the 20's...cant get the same perspective with just the back up cam
 

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Discussion Starter #29
What happens if you go full throttle in 1 and just keep your foot down and don't shift? Does the rev limiter kick in and just let you run along at 6k? Or does it still bog somehow because you're trying to give it full throttle at or beyond redline? (No, I don't want to try this for myself to find out. You do it.)
Haha, you do that and report back to the class. 😁
 

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Well, I was thinking it might be a (human) timing thing. If there's the least bit of lag in the manual shift linkage (if linkage is the right word), then trying to hit the manual shift right before the limiter kicks in might be hard to get right. That would mean it's not the manual shift per se that's causing the bog, but rather missing/mistiming the shift that's causing it. Does that make sense?
 

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After a year of using the radio I noticed that on SiriusXM display there is a "REPLAY" soft button that lets you rewind to a point earlier in the audio stream. DIfferent streams seem to have different limits on how far back you can go.. some let you go back an hour. You can tune to a talk show in progress, back it up, and then you can skip the commercials when you get to them.
 

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HD radio also lets you do that, amazingly enough. I never remember to do it. Or never hear anything I want to hear repeated.
 

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Discussion Starter #33
Well, I was thinking it might be a (human) timing thing. If there's the least bit of lag in the manual shift linkage (if linkage is the right word), then trying to hit the manual shift right before the limiter kicks in might be hard to get right. That would mean it's not the manual shift per se that's causing the bog, but rather missing/mistiming the shift that's causing it. Does that make sense?
There could definitely be a lag in manual shift mode causing the rpm limiter to kick in.

Here's my guess from one of my earlier posts in this thread:

.......Either the PCM lowers the rpm limit in manual shift mode or manually hitting the +paddle creates a PCM communication lag or similar allowing a few mili-seconds delay between gear shifts enough to skyrocket the rpms to the cut off limit.

I don't know off hand if these new GC's have a separate transmission controller aside from the PCM.
If it does that would explain the crisp auto shift from 1st to 2nd at 6k rpm where the tranny controller is doing the real time gear shifting.
On the other hand with manual shifting, the PCM could be involved to detect paddle shifter movement then relaying the shift command to the transmission controller creating enough of a delay between shifts causing the rpms to skyrocket triggering the rpm limit.
All guesses at this point.
 

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Yes, that's a much more informed and articulate way of expressing my similar but only half-baked thought.
 

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HD radio also lets you do that, amazingly enough. I never remember to do it. Or never hear anything I want to hear repeated.
Well I thought it did but when I looked on the way home tonight I didn't see it. Maybe I made that up. Or maybe I saw it in my wife's Subie. (Either one would certainly explain why I never use it in the Jeep.)
 

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Discussion Starter #36
After a year of using the radio I noticed that on SiriusXM display there is a "REPLAY" soft button that lets you rewind to a point earlier in the audio stream. DIfferent streams seem to have different limits on how far back you can go.. some let you go back an hour. You can tune to a talk show in progress, back it up, and then you can skip the commercials when you get to them.
Was excited to try that out but as fate would have it, unfortunately my Sirius 1 yr. free trial ended yesterday.
Talk about bad timing.
 

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My unexpected find? Rust on the front lip of the hood that is apparently a huge problem with GCs and Pacificas...

I have my ipod plugged in to the USB and stashed in the little upper shelf of the under radio cubby. Perfect spot for it that still lets you use the lower section for other generic stuff.

I think the best is the tons of extra storage around the spare tire. Mine holds a 30' snatch strap with a few shackles, trailer hitch shackle mount, 10' tree saver strap, tire plug kit, AC/DC converter, and Viair compressor.
Is the hood on the WK2 not aluminum? My WK has an aluminum hood?
 
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