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Discussion Starter #1
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 :

Untitled.png

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
 

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Although your math seems correct the reason this guy flipped his Jeep is because of poor throttle management.

His front suspension did unload but in the end,
Too much gas.
 

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This^^^ is absolutely correct, too much throttle coupled with over inflated tires...Even with a decreased height of two inches on the front that jeep would have still flipped.
 

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Its A Heep... I Mean Jeep Thing lol
 

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"Level" at stock height is what I said. Lets break down the differences; Video 1 we have a highly modified jeep on high traction slick rock with a driver that thinks full throttle is the way to get up the hill. Video 2 is a stock height leveled jeep on a smaller degree of incline in loose soil and being driven by someone that may not be capable of full throttle.

Completely differing circumstances but I believe your point of nose rake has nothing to do with why Jeep number one flipped and jeep number two didnt.

This is still a great topic to debate though.
 

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Discussion Starter #11 (Edited)
You really need to wheel more, there is a lot more than 7 variables involved.
yea maybe your right .. i wheel on sands all the time but never did it on rocks and hills

but there gotta be a reason for that low nose which in company eyes is safety off road

if you could bring me a rock by fedex :p
 

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Discussion Starter #15
I like my FJ.
A lot of sand in the UAE.
Hey this isn't your handy work is it?
no this is in KSA .. first time i'v seen this move 15 years ago with FJ40 .. tho was no tires change back then

but you gotta admit .. it's efficient :nerd :grin
 

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yea maybe your right .. i wheel on sands all the time but never did it on rocks and hills

but there gotta be a reason for that low nose which in company eyes is safety off road

if you could bring me a rock by fedex :p
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.
 
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The momentum when turning relates directly to the height of the center of mass and the weight. If the vehicle is heavier in the front, by lowering the front a bit, momentum generated in turns by the back and the front of the vehicle become more similar. Greater momentum in the front than the back can cause the vehicle to lose front traction faster in the front tires than the back tires. Just for this reason, I would make the front a little lower than the back.
 

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Properly aimed headlights on an unloaded vehicle will still point up when you load the rear down unless they're auto/manual leveling lights, so that reasoning doesn't work in my head. Also, I find it hard to believe manufacturers would design their vehicles this way when 99% of the miles driven on these vehicles won't be loaded enough to ride level. If the intention was to have the vehicle loaded down, why are the rear suspension links, sway bar links, drive angles, etc. designed at ideal angles for an unloaded vehicle? If a manufacturer is worried about the rear squatting too much under load, go with a progressive rate spring designed for comfort and heavy loads.
 
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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 is actually also true.
 
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