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4LO Power

Caymanedge

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Starting to push my 21 JLUR offroad. The 8 speed transmission, 4:10 gearing and 4:1 transfer case equate to a real crawl .
However, it is hard to get real power when in that mode. It is taking half throttle plus to get any get up and go when I encounter an obstacle. I am using the transmission in Manual mode and manually shifting between 3rd, 2nd and 1st gears. It's just hard to get it to really bang out the power to bump it.
It seems to be easier to crawl in 4HI, locking the diffs via Tazer when needed, and then call on the power.

Anyone have input on this?

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AnnDee4444

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Lapis

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Isn't that kind of the point of 4LO, to get the engine higher into the power band at lower speeds.

In 1st gear. the trans is 4.71:1, in 4HI - 1:1, axel is always 4.10:1 So engine turning 1000 RPMs (1000/4.71/1/4.10) is ~52 RPMs on the tires

in 4LO (1000/4.71/4/4.10) ~13 RPMs at the tires, so the same speed 52RPMs (52*4.10*4*4.71) ~4016 RPMs

The engine makes more power @ 4000RPMs than it does @ 1000RPMs, So while yes, you're using quite a bit of throttle, that's exactly where the engine should be for power. Lots of power to the wheels at a low speed to crawl over things.

Now if by " bump it" you mean you're trying to run up to an obstacle at a higher speed to bounce your jeep over the obstacle, that's not about power, that's about speed.
 

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Obi.Wan.Shawnobi

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Hold the brakes as you build up your rpms. This will help with boost.

Drive two footed. It helps. I have performance mods, they help too. Lol
 

3VOLVE

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Hold the brakes as you build up your rpms. This will help with boost.

Drive two footed. It helps. I have performance mods, they help too. Lol
Iā€˜ve experienced something similar as the OP, but Iā€˜ve used this method with much greater success to bump it over obstacles.
 
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Obi.Wan.Shawnobi

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So I was thinking about it... anytime you are going on trails, make sure you turn off traction control. On the JK it wasn't really a thing but the JL you absolutely need to turn it off. I was in sand and kept digging in, it was because the throttle would electronically cut out every time I got wheel spin.
 

DavidArmen

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I'm pretty sure the throttle map changes in 4lo for more precision. I bet if you floor it, you'll find your power. Otherwise, maybe you don't need to be in 4lo and 4hi would be good enough?
I would also be almost certain that throttle mapping is completely different when weā€™re in 4Lo.
 

Obi.Wan.Shawnobi

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I would also be almost certain that throttle mapping is completely different when weā€™re in 4Lo.
Yes, it is designed that way so when you go over bumps your throttle control is not sporadic causing undesired vehicle response. But I've noticed the "lack of power feeling" as well.
 

DavidArmen

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I would also bet that the stability control and ABS systems are also limiting full power, despite the fact that ā€œtraction controlā€ is automatically turned off in 4Lo, becsuse itā€™s never truly completely off.

Iā€™ve heard forum members comment that when using the tazerJL to completely disable all the stability control and ABS systems (by holding the traction control button for 5 seconds), the jeep seemed to have more power and would never bog down, albeit it comes with the loss of all of Jeepā€™s electronic stability controls systems.
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