6 speed shifting question
06-14-2011, 05:40 AM
#32
JK Super Freak
My shifts are totally dependent on conditions. I live in a rather hilly area, drive backroads and highways, and have the need to merge with rush hour traffic... often.
I also have 4.10's and am on stock Rubicon 32's. That makes a big difference as to how much room I have to play with using different shift points. In a jeep geared too tall, you're in search of staying in an RPM range where the jeep makes power.
With that said, I've found that my JK has a few notable points in it's powerband...
Under 1,100 rpm, and the motor falls on it's face. Its no mans land.
1,100 - 1,400 is good for flat ground around-town or backroad cruising.
Right around 1,400 is where the motor wakes up a little. I need to be at or above that RPM if I intend to use that gear to merge with highway traffic. If I'm under 1,400, I'm likely not going to get up to speed safely in that gear and will need to grab the next lower.
The motor wakes up some more at 2,100 rpm. You can hear the motor start to sound 'gruff'. That's good engineering on the engine designers part. You know the intake manifold, heads, and cam are matched well. 2100 RPM is a good RPM to make note of for when power is needed. Hills, passing, towing, etc.
Anyone recall where our motors make the most torque and horsepower? I thought I recall torque peaking at about 4,000, and HP up around 4,800. Is that right?
I also have 4.10's and am on stock Rubicon 32's. That makes a big difference as to how much room I have to play with using different shift points. In a jeep geared too tall, you're in search of staying in an RPM range where the jeep makes power.
With that said, I've found that my JK has a few notable points in it's powerband...
Under 1,100 rpm, and the motor falls on it's face. Its no mans land.
1,100 - 1,400 is good for flat ground around-town or backroad cruising.
Right around 1,400 is where the motor wakes up a little. I need to be at or above that RPM if I intend to use that gear to merge with highway traffic. If I'm under 1,400, I'm likely not going to get up to speed safely in that gear and will need to grab the next lower.
The motor wakes up some more at 2,100 rpm. You can hear the motor start to sound 'gruff'. That's good engineering on the engine designers part. You know the intake manifold, heads, and cam are matched well. 2100 RPM is a good RPM to make note of for when power is needed. Hills, passing, towing, etc.
Anyone recall where our motors make the most torque and horsepower? I thought I recall torque peaking at about 4,000, and HP up around 4,800. Is that right?
06-14-2011, 06:40 AM
#34
JK Junkie
06-14-2011, 06:47 AM
#35
JK Enthusiast
Join Date: Aug 2010
Location: Milwaukee, Wisconsin, United States
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Originally Posted by bowerss2
seriously? 4K high rpm????
06-14-2011, 07:37 AM
#37
I will sometimes drop it to 3rd at highway speeds if I need some nuts to pass going up hill....I will see 4800-5000RPM
100-110km/hr. It just spits out the built up carbon from my wife driving it around town like a grandma.
Normally I shift at 2500-3500 RPM depending on conditions.
100-110km/hr. It just spits out the built up carbon from my wife driving it around town like a grandma. Normally I shift at 2500-3500 RPM depending on conditions.
06-14-2011, 10:05 AM
#38
I drive truck for a living, and I don't know anyone more then 6 months out of school that uses the clutch except for starting off, or to clutch it out of gear if shifting up or down a grade.
Can you float the gears in a Jeep/pickup/car though? Ya, would I? Not unless you're good at it, you will destroy syncro's if you don't know what you're doing, and helical cut gears aren't as forgiving as straight cut gears. When I took an 11 for a test drive the other day it took me a couple blocks to realize i wasn't using the clutch out of habit from work and had no problems.
But knowing how to do it can get you home if the clutch won't disengage.
Can you float the gears in a Jeep/pickup/car though? Ya, would I? Not unless you're good at it, you will destroy syncro's if you don't know what you're doing, and helical cut gears aren't as forgiving as straight cut gears. When I took an 11 for a test drive the other day it took me a couple blocks to realize i wasn't using the clutch out of habit from work and had no problems.
But knowing how to do it can get you home if the clutch won't disengage.
Agreed, it works in an emergency, and that was the point I was getting across. It can be done, but its not recommended.
As far as the semi drivers not using a clutch, again, i have yet to see an owner operator match RPMs in lieu of using a clutch(on a regular basis). Seing as the transmission is un-sync'd, you have to match rpms when you clutch out anyways. Not to do so is lazy, and wears on your transmission.
The clutch is there for a purpose. Use it. Replacing a clutch is more affordable than a transmission.