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Weak Throttle Response on Manual Transmission Models?

8flat

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remember, a lot of us are coming from an inline 6 cyl. 4.0l off idle torque was much different than this 3.6l
Now there's a 6cyl that's much more suited to off-road. I think they could've designed this 3.6 to be somewhere in the middle, with a larger stroke to improve off-idle torque, but still able to rev better than the old 4.0 so it's better at highway speeds.
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TheKeither

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Yep I'm guilty, came from trucks.
BUT: this thing has a tow package. Try backing up a trailer and "use the rev range"...hahaha

And it designed for off road, i.e. getting buried in mud or snow where you need the lockers (I have, many times). Yes 4LO helps, but in deep snow you need wheel speed and 4LO is too low. With no off-idle torque, it'll barely get the tires spinning in 1st gear. Very strange.

A longer stroke crankshaft, with a lower redline like maybe 5K, would be much better for this application.
I hear you, and I am not an apologist, per se. But given the compromises made for the sake of fuel economy, its a pretty damn good package....not perfect by any means (392 should be STANDARD!) but a damn good package.

Now....You may complain alllllllllllllllll you want about reverse and I will back you up (no pun intended) 100%. Its just stupid tall.
 

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As some others have said, my experience with the 3.6 is that it likes to be in higher revs than we're used to, especially offroad. If you were taught to shift ~2500 like I was, then you'll be pretty disappointed with the output that low.
 

8flat

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I hear you, and I am not an apologist, per se. But given the compromises made for the sake of fuel economy, its a pretty damn good package....not perfect by any means (392 should be STANDARD!) but a damn good package.

Now....You may complain alllllllllllllllll you want about reverse and I will back you up (no pun intended) 100%. Its just stupid tall.
I would think that a redesigned 3.6 with with larger stroke and smaller bore, but still resulting in the same 3.6liter displacement, wouldn't necessarily use more fuel. Not positive. I'd love to talk with an engine designer on this topic.

Yeah holy shit that reverse gear....haha.... another aspect that seems more at home in a car not an off road rig with tow package. Very bizarre. And frustrating. My clutch is not long for this world.......
 

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grimmjeeper

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I will say that in my JK, I put in the Centerforce clutch kit with the heavier flywheel. The off idle performance improved quite a bit when I did that. The extra surface are of the clutch disc and pressure plate over the factory part helped as well.

If they're still using the same light flywheel and there is a good heavier flywheel and clutch available, I'd highly recommend it.
 

JRINGO77

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remember, a lot of us are coming from an inline 6 cyl. 4.0l off idle torque was much different than this 3.6l
Maybe somewhat but that engine only had 190 ft lbs and a TJ couldn't weight more than 3500 lbs compared to almost 5k for a JL. The 4.0 was good off road but not great anywhere else and was terrible on fuel.
 

8flat

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I will say that in my JK, I put in the Centerforce clutch kit with the heavier flywheel. The off idle performance improved quite a bit when I did that. The extra surface are of the clutch disc and pressure plate over the factory part helped as well.

If they're still using the same light flywheel and there is a good heavier flywheel and clutch available, I'd highly recommend it.
That's a great idea. It helps a ton on dirt bikes like the old 2 strokes with no off-idle torque, I don't know why I didn't think of it for a JL.
 

grimmjeeper

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Maybe somewhat but that engine only had 190 ft lbs and a TJ couldn't weight more than 3500 lbs compared to almost 5k for a JL. The 4.0 was good off road but not great anywhere else and was terrible on fuel.
It was 190 hp. It had 235 ft-lbs. And most of that torque was available at low RPMs.
 

Richtor

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I made an offer on several 6sp man 20 JL's after the fix but did not drive one. I put 74k miles on my 12 2dr Rubi 6sp and it was flawless, no complaints at all.
OP if your shifting at 2.5 you are going into 2nd at what 1.5 while you're still trying to accelerate. 1.5 rpms while your at your cruising speed is fine but not when you want to add power or speed. Whats the first thing you do when you want to pass/accelerate? Shift down....
You should be at 3.5-4.5 when gaining speed and then at 1.5 when maintaining speed. Drive in this fashion and you will see a world of difference....
 

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CJ SCION

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Holy cripes, you folks use all the gears? I find it more than adequate as a 3-speed, 1-3-5. My vehicle is a JK 2-door and will use 6th gear on the freeway which is not very often. 4.10 axle gears and 35s. Ya know Chevy had 2-speed autos and their Turbo 450 is a 3-speed auto, 2.48-1.48-1:1.

When first driving the Jeep 6-speed manual (after years with the AX15), I was stalling too often when leaving the line. There is a procedure to re-calibrate the throttle response on these vehicles. Take a google ride and you come across such threads, it is not Jeep specific but it gave immediate results in my case.
 

Johnbuz

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It was 190 hp. It had 235 ft-lbs. And most of that torque was available at low RPMs.
Holy cripes, you folks use all the gears? I find it more than adequate as a 3-speed, 1-3-5. My vehicle is a JK 2-door and will use 6th gear on the freeway which is not very often. 4.10 axle gears and 35s. Ya know Chevy had 2-speed autos and their Turbo 450 is a 3-speed auto, 2.48-1.48-1:1.

When first driving the Jeep 6-speed manual (after years with the AX15), I was stalling too often when leaving the line. There is a procedure to re-calibrate the throttle response on these vehicles. Take a google ride and you come across such threads, it is not Jeep specific but it gave immediate results in my case.
Here in western PA, we have lots of hills so I use all the gears. Well usually 1-3 up to 45 mph and 4th up to 55. 5th is for expressway cruising. 6th is useless. Even at 75mph, 6th cant climb any hills.
 

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The thing that drives me nuts with mine is the rev hang. 4500rpm, it will hang. Impossible to shift smoothly when it does that. Still better than any JK manual I test drove, but should have gone with the 8spd. The 3.6 seemed really well matched to that trans.
 

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🤔

Sorry to be Steve Jobs, here, but you’re holding it wrong.

Yes, if you lug the engine it’s “a pig.” Don’t do that. The 3.6 likes to rev. It doesn’t redline until 6,500… no need to ever keep rpm under 2000 like you’re doing.

Yes, 6th gear is useless in stock configuration. Yes, reverse is too tall.

My 6sp with 4.10’s (Rubicon) is excellent. I hear that with 3.45’s it’s not a great on-road experience.

Throttle response is not an issue.
It's an issue in the 3.45.

So I want to let it rev, but every time it screams at RPMS over 2500 and just feels wrong. What do you think about that? Should I just let it scream and keep the revs high?
 

OldGuyNewJeep

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It's an issue in the 3.45.

So I want to let it rev, but every time it screams at RPMS over 2500 and just feels wrong. What do you think about that? Should I just let it scream and keep the revs high?
Yes.
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