[Lightpath]

The reason all trucks and most suv's are taller in the rear is so the vehicle will sit level once loaded. They also do this so the head lights wont blind people if the vehicle is loaded down. It has nothing to do with aerodynamics or off road improvments.

^ This
Especially with pickup trucks this is critical. Over loading a pickup truck and floating the front end can be pretty dangerous. Giving some forward rake helps to keep this from happening.

 

[lzalusky]

some believe that nose down on 4x4 vehicles are just a manufacturer error
other's believes it's just for car aerodynamic
but after thinking it's gotta be a greater reason for that, otherwise the factory would do a recalling process.

yesterday someone posted on facebook about jeep wrangler flipped over 45 degree "more or less" small rock ramp .. i got stunned !! i mean how is that even possible with these amazing mods he added ??
after replaying that video more than 10 times, i noticed in the first seconds of the video the front wheel height match the rear wheel height "and maybe little higher"
after it flipped over, the wheels in front much higher than the rear wheels.

so it come's to me !! it's not just about vehicle aerodynamics !! it is also about physics and vehicle handling.

look at this picture :

View attachment 303817

this picture of a car had it's nose up by whatever of coils spacers etc.
regardless about how cool it looks when we do that, it fails on hard off road
now this picture is too long to explain but the bottom line is this :

as long (Fmg"sin") is a lot smaller than (Fmg"cos") on any ramp , your ok.

knowing that (Fmg"sin") increases by hard pressing on gas pedal, high ramp angle and the type of suspension you have .. more harder suspension more better and safer to climb.
and (Fmg"cos") increases by car momentum and nose down low ramp angle

that's why the reason of the nose down and you should never change it with spacer nor coils neither front lift kit if you want to offroad with it.

want to get your vehicle higher ??
buy a full off road suspension kit from trusted company

To cause the vehicle to flip you have to move the center of mass behind the rear axle to flip backward, or in front of the front axle to flip forward. Lifting the vehicle moves the center of mass upwards and reduces the angle required to get the center of mass over the axles.

What happened in that video as others have stated is purely due to horrible throttle control. You can see that it only starts to flip once he has throttled it close to 90 degrees. No amount of drop in the front end was going to save that guy:smile

 

[FJ Moose]

The coefficient of the center of gravitational rollover is inversely rooted the 5th derivative of sin(of the driver's intoxication level) :cheers:

 

[FJNewb]

Everyone is wrong. His throttle control was spot on.............until he let off rather than throwing it in reverse and staying on the gas :lol: #neverlift

 

[FJ Moose]

Everyone is wrong. His throttle control was spot on.............until he let off rather than throwing it in reverse and staying on the gas :lol: #neverlift

You're wackadoo!!! Please explain ye answer

Because I know you know that I know you know :cheers:

 

[mackb]

The coefficient of the center of gravitational rollover is inversely rooted the 5th derivative of sin(of the driver's intoxication level) :cheers:

:laugh bwaaa hahahahaha!!

 

[lzalusky]

The coefficient of the center of gravitational rollover is inversely rooted the 5th derivative of sin(of the driver's intoxication level) :cheers:

I didn't want to get that technical, but yes exactly :rocker: I think the last term is probably the most important.

 

[FJNewb]

You're wackadoo!!! Please explain ye answer

Because I know you know that I know you know :cheers:

Insufficient time to draw sufficient Free Body Diagrams to sufficiently articulate the importance of insufficient unicorn tusks and rainbows when it comes to throttle position. Basically it comes down to you should never lift, just shift :cheers: :lol:

 

[7amody]

The whole problem with your logic is that it reverses when going down hill. Obviously, with the nose down when going down hill, you're much more likely to roll over forward, especially with a vehicle that has more weight on the front than the rear. Toyota wouldn't have factored this in for rollover purposes for inclines/declines because not everyone goes up hill only.

Fuel efficiency is the main reason as the coefficient of drag and frontal area is reduced with a lower front, but I'm willing to bet the lower center of gravity doesn't hurt on lateral rollover safety ratings either.

Fs is Friction force or resistance force .. the vehicle going up the hell, the F way "sound like a bad word".

i'm saying that the nose down probably for safety reasons "physical reasons" , since it's been built to be working on/off roads unlike normal cars.

and rolling over forward ?? really xD
when we go down the hell is different thing because the front is much heavier than rear so unless its 90 degree hill you'll have nothing serious

 

[FJ Moose]

Insufficient time to draw sufficient Free Body Diagrams to sufficiently articulate the importance of insufficient unicorn tusks and rainbows when it comes to throttle position. Basically it comes down to you should never lift, just shift :cheers: :lol:

:lol:

Is that never put on a lift, or never lift the front with too much throttle :lol:

Fs is Friction force or resistance force .. the vehicle going up the hell, the F way "sound like a bad word".

i'm saying that the nose down probably for safety reasons "physical reasons" , since it's been built to be working on/off roads unlike normal cars.

and rolling over forward ?? really xD
when we go down the hell is different thing because the front is much heavier than rear so unless its 90 degree hill you'll have nothing serious

You think it's hard to roll going downhill? Straight down, no, but any off camber and you're in serious trouble quickly.

 

[3L5 Lego]

I found this thread funny in so many way.

 

[jasonfjc]

flipping over is more complicated than looking at your car as a simplified point object.
flipping over has something to do with torque because flipping over is a rotating motion.
going down hill and you have short wheelbase and very light in the back, you are going to start rotating forward if you brake hard enough if torque is strong enough to lift the back end.
same with uphill, if your front is light and you have too much throttle you flipping backwards.
long wheelbase is better than short wheelbase, lower car is better than higher car.

 

[mikey]

If an airplane is on a treadmil...

 

[bazross]

The reason all trucks and most suv's are taller in the rear is so the vehicle will sit level once loaded. They also do this so the head lights wont blind people if the vehicle is loaded down. It has nothing to do with aerodynamics or off road improvments.

Thats why Yota fit actuators to our headlights so we can adjust them depending on load from the dash....
Cheers
Baz
:blueblob:

 

[WaJohnZ]

If an airplane is on a treadmil...

:laugh:laugh

 

[FJess]

The coefficient of the center of gravitational rollover is inversely rooted the 5th derivative of sin(of the driver's intoxication level) :cheers:

More simply put, the angle of the dangle is inversely proportional to the heat of the beat.

 

[Lightpath]

If an airplane is on a treadmil...

Gotta love Myth Busters!

 

[BIGGUY]

Thats why Yota fit actuators to our headlights so we can adjust them depending on load from the dash....
Cheers
Baz
:blueblob:

Aren't those nice. I adjust mine down a bit to get better light in front of me since I'm usually not running fast and it works pretty good.

 

[mikey]

Gotta love Myth Busters!

Used to, not so much anymore.


Like some one else mentioned that when loaded you sit level....it's not about where your lights are shining it's about maintaining weight over the front wheels.

If you are squatting in the rear you are light up front this = less steering control and poorer braking. With the load too the rear now your rear brakes are taking working harder than the fronts...not what they are meant for.

 

[_Bacchus_]

The reason all trucks and most suv's are taller in the rear is so the vehicle will sit level once loaded.

This.

They're designed that way so they don't squat when running with a typical load.

I guarantee Jeep engineers didn't lower the front an inch and a half on every wrangler they sold because they were concerned about the .01% idiot factor rolling his junk over backwards.