The Homebrew Jeep Mod Thread
Seasoned Member
Joined: May 2012
Posts: 436
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From: Ware Shoals, SC
Year: 1993
Model: Cherokee
Engine: 4.0L
That has nothing to do with speed of impact. One is an immovable object, the other is designed to absorb impact. Does not change the force of the impacts!
CF Veteran
Joined: Jul 2013
Posts: 1,466
Likes: 6
From: St. Joseph, MO
Year: 1994
Model: Cherokee
Engine: 4.0
CF Veteran
Joined: Jul 2013
Posts: 1,466
Likes: 6
From: St. Joseph, MO
Year: 1994
Model: Cherokee
Engine: 4.0
it's Newton's 3rd law... "When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction to that of the first body"
The force from car A acts on car B, and the force from car B acts equally on car A. The force starts at the front of each car and travels back, leaving each car with a single 50 mph impact. Since the kinetic energy of both cars is dissipated as a result of the collision, each car recieves roughly half of the "damage" from the impact. So, (1/2)mv^2 + (1/2)mv^2 = mv^2. However in the other scenario (a 100 mph car into a wall), the car has twice the velocity. Since the wall is stationary, it has no kinetic energy. The energy is dissipated into the car only, and the single car will receive all of the "damage" from impact. Thus, (1/2)m(2v)^2 + 0 = 2mv^2. So technically speaking, crashing into the wall is twice as bad.
just gotta look at the actual physics behind the thing
The force from car A acts on car B, and the force from car B acts equally on car A. The force starts at the front of each car and travels back, leaving each car with a single 50 mph impact. Since the kinetic energy of both cars is dissipated as a result of the collision, each car recieves roughly half of the "damage" from the impact. So, (1/2)mv^2 + (1/2)mv^2 = mv^2. However in the other scenario (a 100 mph car into a wall), the car has twice the velocity. Since the wall is stationary, it has no kinetic energy. The energy is dissipated into the car only, and the single car will receive all of the "damage" from impact. Thus, (1/2)m(2v)^2 + 0 = 2mv^2. So technically speaking, crashing into the wall is twice as bad.
just gotta look at the actual physics behind the thing
Last edited by kelly4; Aug 6, 2013 at 09:41 PM.
One of the other guys in the new mexico roll call had a accident and he had the stiffeners and I think that what saved his jeep from being even more tweaked, then what it was and the truck that he hit/hit him was destroyed and he had a stock bumper and still drove it home.
CF Veteran
Joined: Oct 2011
Posts: 1,812
Likes: 0
From: South Mills, NC
Year: 1998
Model: Cherokee
Engine: Rebuilt 4.0L I6
One of the other guys in the new mexico roll call had a accident and he had the stiffeners and I think that what saved his jeep from being even more tweaked, then what it was and the truck that he hit/hit him was destroyed and he had a stock bumper and still drove it home.
CF Veteran
Joined: Oct 2011
Posts: 1,812
Likes: 0
From: South Mills, NC
Year: 1998
Model: Cherokee
Engine: Rebuilt 4.0L I6
One of the other guys in the new mexico roll call had a accident and he had the stiffeners and I think that what saved his jeep from being even more tweaked, then what it was and the truck that he hit/hit him was destroyed and he had a stock bumper and still drove it home.
It was a head on with a full size truck the front of the jeep was bent pretty bad the rad lower and upper support were destroyed, the front shifted about a inch out on driver side and about twp on the pass. Hood was bent in the front not real bad, both fenders shifted. But was still able to open doors without binding if I remember. The other truck was worse and had to be towed. It been about id say maybe 5 months ago this happened and still haven't gotten the jeep back yet, I don't think. He was lifted about 4 inches and had just got his currie steering upgrade too before he wrecked.
Senior Member
Joined: Nov 2010
Posts: 976
Likes: 5
From: Cloquet, MN
Year: 2000 Ltd.
Model: Cherokee
Engine: 4.0L I6
Something to keep in mind with these home modifications to the chassis, is that while in the example above the guy drove the Jeep home because it took less damage, the vehicles are designed to absorb the energy of the impact and not transfer it to the occupants. Stiffening up the frame may save the jeep, but if you get in a really back wreck in your daily driver your body will have to absorb the energy that the vehicle doesn't. Stiffening a trail rig is no big deal, but for a daily driver it's something to keep in mind, especially if you're a family man. Don't need to be
. But, to each his own.
. But, to each his own.
CF Veteran
Joined: Aug 2011
Posts: 1,994
Likes: 8
From: San Jose
Year: 89
Model: Cherokee
Engine: 4.0 I6
Something to keep in mind with these home modifications to the chassis, is that while in the example above the guy drove the Jeep home because it took less damage, the vehicles are designed to absorb the energy of the impact and not transfer it to the occupants. Stiffening up the frame may save the jeep, but if you get in a really back wreck in your daily driver your body will have to absorb the energy that the vehicle doesn't. Stiffening a trail rig is no big deal, but for a daily driver it's something to keep in mind, especially if you're a family man. Don't need to be
. But, to each his own.
. But, to each his own.


