• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Degrees before jeep rolls?

buschwhaked

buschwhaked

NAXJA Forum User
Location
Colorado Springs
Ok, random question here but before I ask a couple things:

1) I apologize for the crude drawing. It is definitly not to scale (duh) but the best my creative talents could come up with and the only way to illustrate my question.

2) Don't know if this is in the right forum, but it's a pretty random question.

How many degrees do you think a jeep can sit on before it rolls? I don't have a quick disconnect yet for the sway bar but a 3" lift so far. I took it up probably to about 35* today and it felt like it was about to tip so it made me wonder.

degreestilltip.jpg
 
Depends strictly upon the CG of your rig - you will have to take some weights on your vehicle (as loaded for a trip) and apply some maths.

Then, apply a little trig to find out how far you have to tip before you have your CG outside of your "footprint."
 
5-90 said:
Depends strictly upon the CG of your rig - you will have to take some weights on your vehicle (as loaded for a trip) and apply some maths.

Then, apply a little trig to find out how far you have to tip before you have your CG outside of your "footprint."
Click to expand...
Also consider how soft or firm your suspension is.

Other things:
Are all tires on the ground, and level with eachother.

Are you moving, stopped, sliding, etc

Wind pressure, humidity, and planet alignments


Basically, there is no given figure that you can reasonably figure out.

That being said, heres a picture of me. This was after it came down a bit too.

548098613_l.jpg
 
I've had my clinometer reading 35 degrees on the 197 trail at Evans Creek. There were a couple bumps that made it more, but 35 is the highest number I saw.
 
vetteboy said:
Do you happen to read XKCD?

I believe the tipover angle is a little less than this.

I've always wanted to put a clinometer with a redline on my dashboard.
Click to expand...

XKCD? Whuzzat?

Not a clinometer tho - an attitude indicator from an aircraft, I think. I know, I've got a lot of strange ideas...
 
XKCD is a nerd-oriented comic, and one prevailing theme is the use of "maths" over "math" when talking about a means of figuring out a problem. :)

I'm much more interested in pitch and roll movement than yaw...although a 3-dimensional redline is an interesting concept.
 
vetteboy said:
XKCD is a nerd-oriented comic, and one prevailing theme is the use of "maths" over "math" when talking about a means of figuring out a problem. :)

I'm much more interested in pitch and roll movement than yaw...although a 3-dimensional redline is an interesting concept.
Click to expand...

Oh. Nah - just spent too much time talking to Britons.

(And a basic attitude indicator will cover pitch and roll in the same gage...)
 
Mom's FJ came with a tiltometer... Need to swipe one out of the old cessna...
 
Damn dude...math? trig? XKCDTREGJNB? Just looking for a ball park number. Tires are stock right now and Pro Comp is pretty stiff.

The LMTV (an Army vehicle) has a tiltometer, I think it would be really cool to put one in a jeep. But I guess there really isn't a way to figure out the red line w/o a lot of math that is way above my head.
 
buschwhaked said:
Damn dude...math? trig? XKCDTREGJNB? Just looking for a ball park number. Tires are stock right now and Pro Comp is pretty stiff.

The LMTV (an Army vehicle) has a tiltometer, I think it would be really cool to put one in a jeep. But I guess there really isn't a way to figure out the red line w/o a lot of math that is way above my head.
Click to expand...

Of course there's a way to do it without math. It's called an experiment. May not be worth it though.

If you think you're getting close, get on the high side and see if you can lift it up. If you can you've found the limit. Just don't kill anyone in the process.
 
This is what RTI ramps are all about. Get to a 25* to 30* ramp, run the xj up till the left rear comes off the ground. Go a little farther till it gets light and you have your comfort factor when on an obsticle. The RTI ramp will also tell you where you are binding, if your shocks are correct, if you need to consider cutting the fender wells, if your track bar axle bracket needs trimmed and of course, point out how a locker will help you get into trouble. :laugh:
Other than that it is a matter of the math.
 
This is a classic "statics" problem.

There is a way to calculate this but it is far too complicated to explain without a good drawing of all the forces involved. (This is called a "free body diagram.")
 
You must log in or register to reply here.

Similar threads

J
Help needed with nightmare XJ ABS to Non-ABS swap...
Replies
0
Views
69
JBinNY
J
X
My brakes are crap
Replies
12
Views
3K
xjklmnop69
X
K
96 XJ 4.0 LOW COMPRESSION QUESTION
Replies
6
Views
3K
Evan03
E
M
New and need help
2 3
Replies
41
Views
9K
Evan03
E
E
96 XJ Fuel Pressure Sensor?
Replies
7
Views
2K
East_tx_dad
E
Back
Top