I don't like rock crawling so I hit the first obstacle going 60 and just Evil Knievel over the whole trail. Makes everything much easier.
Peak Crusing RPM?
- Thread starter astjp2
- Start date
I don't like rock crawling so I hit the first obstacle going 60 and just Evil Knievel over the whole trail. Makes everything much easier.
Oh good Grief, and here I am contemplating 5.13's in my SE so I can crawl a steep, tight trail without having to get into 4lo. Once again, doing it wrong.
Airjunky
TJ Enthusiast
Yea, built by a previous owner, they definitely did that part right. I think there is still plenty of torque to go to 33s & not lose much power.
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And here i've been, using 4Lo as a low range gear reduction for better torque over obstacles.....I'm an idiot.
I did read about that once. But I tired of the baseless drivel so I no longer see posts of that nature.
In the app, you can choose exactly those 'gauges' that I mentioned. I usually have them in a digital format grouped together. I monitor speed via GPS, since my speedo is not recalibrated, RPM, engine load, intake temp, coolant temp and then some sort of fuel usage numbers. Along with a few other small items I keep an eye on for kicks (altitude, compass) I am on a new phone since I last played with it, so I have lost the set up I had. I am going to try to set up an old phone as a permanent gauge cluster of sorts this Spring when the Jeep is back together. It's a really handy app, although I wish our Jeeps had more information available, like trans temp. 2700 RPM would be a good spot to be in too, I would think. I think the OD gear in your manual is a little less deep than the OD in the autos - around .85? That would make a world of difference in getting the automatics to run down the highway better I think.
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Airjunky
TJ Enthusiast
Nice. I'm a new Torque user. I have it setup for towing in a Chevy Avalanche, monitoring Trans temp, coolant temp, HP & torque. Really enlightening stuff. Just this weekend I put the ODBII dongle in the Jeep for the first time to read & clear codes.... its been holy crap cold here so I've seen P0155 for the 02 sensor preheat a few times. I never could get Torque to clear the TJ codes, although it works fine on the Avalanche and my wife's Grand Cherokee. I ended up downloading an app called Car Scanner that clears the TJ codes easily. I'll setup a dash & monitor some of this too.
2006TJ1
TJ Enthusiast
Here in Atlanta, if I ran at 55 mph on I75 or I85 I'd get into an accident from someones road rage. I stay in the slow lanes and still have to maintain 65ish mph to keep up with traffic. I75 traffic gets backed up enough, I'm not going to be the cause of any more. My MPG can suffer a little.
I am thinking 4.56's and a 4.3 atlas, if I want to go slow, I can shift in to low, if I want to cruise I still can. There is also less reported driveline vibes with 4.56, with the number of issues when people are going to 4.88 and higher, I would rather avoid them. Tim
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mgroeger
TJ Enthusiast
Aint that the truth.
At my last company we had GPS trackers/monitors, if you turned to hard, accelerated to fast, sped, or had harsh braking it dinged you and your driving score that the company watch dog was overseeing. I was driving from Englewood out to Watkins everyday for two weeks for work at a compressor station. The speed on that stretch of I70 is 55 mph, I tried doing that and I literally had people swerving around me because they were doing 80 mph. I finally started to go with the flow of traffic with the GPS tracking device beeping at me the entire time. I got a slap on the wrist at work for not following safe driving practices, I tried to explain that doing the posted speed limit is more dangerous to my life. Their response "you need to obey all posted speed limits".
I go thru there in my work van daily, at the speed limit in the slow lane, people actually get the number off the side of the van to call the shop and complain that I am driving to slow and creating a hazard. As they are driving 80-85 mph and getting a phone number.
Jesus the blatant misinformation on this thread... 
4.0 33s 4.56 NV3550.
This is going up a steep incline in 4th.
And cruising in 5th.
This thing purrs right along at those revs, with throttle to spare.
4.0 33s 4.56 NV3550.
This is going up a steep incline in 4th.
And cruising in 5th.
This thing purrs right along at those revs, with throttle to spare.
| Gear Shift Drop Calculator nsg 370 | |
RPM: | RPM 2500 |
Rear Gear Ratio : | 4.11 |
Tire Diameter: | Inches 33 |
Gears in Tranny: (3 Speed or 4 Speed, etc.) | 2 Speed 3 speed 4 Speed 5 speed 6 Speed |
1st Gear Ratio: | :1 |
2nd Gear Ratio: | :1 |
3rd Gear Ratio: | :1 |
4th Gear Ratio: | :1 |
5th Gear Ratio: | :1 |
6th Gear Ratio: | :1 |
|
After 1st Shift: 1,466 RPM. 41.38 % RPM Drop After 2nd Shift: 1,648 RPM. 34.09 % RPM Drop After 3rd Shift: 1,741 RPM. 30.35 % RPM Drop After 4th Shift: 2,083 RPM. 16.67 % RPM Drop After 5th Shift: 2,095 RPM. 16.20 % RPM Drop 1st Gear is 13.80 MPH at 2500 RPM 2nd Gear is 23.55 MPH at 2500 RPM 3rd Gear is 35.72 MPH at 2500 RPM 4th Gear is 51.29 MPH at 2500 RPM 5th Gear is 61.55 MPH at 2500 RPM 6th Gear is 73.45 MPH at 2500 RPM1 |
Shift Calculations at 2700 rpm (cruising rpm) for 4.0, 42RLE, 5.38 gears, 35" (34.5") tires, which illustrate that the drop from 3rd into OD in 42RLE is more akin to a full gear vs. the 1/2 gear of a typical overdrive gear and why such low axle gears are necessary for this transmission:
1st - 2.84:1
2nd - 1.57:1
3rd (D) - 1.0:1
4th (OD) - 0.69:1
After 1st Shift: 1,493 RPM. 44.72 % RPM Drop
After 2nd Shift: 1,720 RPM. 36.31 % RPM Drop
After 3rd Shift: 1,863 RPM. 31.00 % RPM Drop
1st Gear is 18.14 MPH at 2700 RPM
2nd Gear is 32.82 MPH at 2700 RPM
3rd Gear is 51.53 MPH at 2700 RPM
4th Gear is 74.68 MPH at 2700 RPM
1st - 2.84:1
2nd - 1.57:1
3rd (D) - 1.0:1
4th (OD) - 0.69:1
After 1st Shift: 1,493 RPM. 44.72 % RPM Drop
After 2nd Shift: 1,720 RPM. 36.31 % RPM Drop
After 3rd Shift: 1,863 RPM. 31.00 % RPM Drop
1st Gear is 18.14 MPH at 2700 RPM
2nd Gear is 32.82 MPH at 2700 RPM
3rd Gear is 51.53 MPH at 2700 RPM
4th Gear is 74.68 MPH at 2700 RPM
Purely your decision but, I wouldn't be too quick to dismiss a gear lower than 4.56 based on a few problems floating around the 'net. You always hear about the negatives, rarely the positives. But again, the choice is yours.
You could convert to manual hubs to eliminate any vibrations that might result from re-gearing to a lower ratio for a lot less money than an Atlas.
Just sayin'.
I am putting on manual hubs with a HP Dana 44 from a ford that I am going to narrow down. Eventually...Tim
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