Woodrow's 97 Green TJ Moderate Build
- Thread starter Woodrow
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Imagine the torque figures in low range
Yeah. Huge. I think about that when I'm wedged against a rock in low range and 1st gear. 5.0 x 3.83 x 215 ft. lbs. becomes 4117 ft. lbs. SNAP!
I think you missed a number there, Mikey - you are way more than 4117...
I'm around 50,000...
My math says he’s right…for easy maths…. 200 x 5 =1,000 x 4 = 4000
I left out the 5.13 axle as its part of of the dyno number. But with that then 21,121 (not exactly hemi numbers, eh?)
Last I spoke with Mike, he was not running 1:1 at the diffs...
Yeah, but that’s not leaving out a zero.
The dyno number (215 ft. lbs) must be calculated to give engine numbers. I assume actual torque on the roller is higher because of the axle ratio. Also the tire diameter probably matters too if you are talking about torque the axle shaft sees.
It's just a fun number to throw around, because to actually generate that torque number you also need a bunch of resistance - and that's tough to get at wide open throttle.
But, it's still fun to toss it out there.
I don't know how any of that works.
Yes, and no. Torque is a function of resistance. You can bind up a stock size tire to create the same resistance and potential for breakage as you can a 40" tire.
Torque to the ground yes,but the tires being after the shaft won't affect the input to them at the diff
100%. The longer lever arm is the main reason bigger tires break stuff.
The dyno roller (or ground when driving) only "sees" horizontal force. You could call it thrust. Using your peak torque output number of 21,121 lbft, divided by an effective radius of 17/12 in/ft, you'd have a peak thrust of 14,909 pounds. Assuming your TJ weights 4500lb you'd have a momentary peak acceleration of 3.3 g. Just a little less than the SpaceX Starship.
If only the tires had the traction.
I have not experienced rocket like acceleration sensations in my Jeep. Maybe I'm doing it wrong?
Have you tried doing a hard launch on the street in 4-low? It's waiting for you there. Possibly along with a list of new repairs.
I did it once in my XJ. It pushed me back HARD and the tach revved almost as fast as it does in neutral. Too quickly for the aw4 to shift it time so it bounced off the rev limiter, effectively slamming on the breaks (1st-gear low range engine breaking at redline) and pulling my head forward for a split second, then the transmission shifted with a BANG and it leapt forward like I was rear-ended by a dump truck. I got mild whiplash and my neck was sore for a week.
I wish I had taken video.
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Since he's got a Atlas he could do a 2LO launch instead... That might really task the Dana 44 to a breaking point and when the R&P locks up from sheared teeth it'll be like slamming on the brakes.. Or his AX15 might not enjoy it too much either... But he could do a 3rd or 4th gear launch with this 5:1 gearing in his t-case...
I've honestly never felt the need to attempt a 4WD or 2LO launch on the street... Or not that I can remember at least.
Nope.... Unless you're willing to pay for the tires & any broken parts WHY???? I break shit enough without trying to do shit like that.
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