Why crossovers can't articulate?

Why? What is the technical reason? You get the best crossovers out there and their wheels can't stay on the ground and start spinning in the air. What is their problem? Why can't their suspensions let their wheels go loose and stay on the ground.
Today I went over some rocks and crazy angles in my 4Runner and damn my wheels stayed on the ground all the time. It will take some serious obstacles to get the 4Runner in the air. The thing freaking stays glued to the ground. Why can't they design the Rav4 to flex like that? Is the unibody the culprit? Bear with my question as I am a layman.
Thanks!

 

This video shows my point, Crossover Vs. 4Runner. It is so painful to watch that crossover.


https://youtu.be/3JRmU6OqYPE

 

And one more thing. I am in love with my 4Runner. What a beast it is. I can't believe I finally bought one

 

Unibody can’t flex??,

 

Heavily modified. So it means they can flex. So what is the reason, why these crossovers can't articulate. Rav4s, Subarus, Fords, Hondas?

 

https://www.youtube.com/watch?v=IhbXPzPlzNI

 

Thanks. I got the answer from the end of the video. A combination of a frame and a good suspension will help flex and ariculate. But the question arises, why can't a unibody have a good suspension to help flex and ariculate? Will that affect ride quality, handling and mpg, and manufacturers aren't willing to hurt those things? Because even a fancy unibody like the Defender lacks crazy articulation.

 

Anythings possible. In my minds eye I see it looking like a daddy long legs spider..........a very expensive one at that.

 

Maybe understanding the mechanisms at play in suspension would help?

pivot points on most unibody (crossovers use this design) suspensions are designed for road surfaces. Lifting doesnt change articulation because the pivot points on the suspension and distance of the wheel dont/cant change much. If you were to move the pivot point further in from the wheel, then you get more articulation. Case in point with the jeep posted above. Its the same unibody design as any other crossover, but with a solid axle making the effective pivot points located at the other side of the car.

 

Daddy long legs, it is.

 

/thread

 

FWIW....

Suspension articulation is not determined by the Uni-body or Body On Frame construction. The primary driver for suspension articulation is whether the vehicle utilizes solid axles or independent axles.

In a solid axle application such as Jeep uses on the Wrangler and Gladiator, when an obstacle pushes one wheel on an axle upward, there is pressure exerted on the opposite wheel on the axle in a downward direction keeping both wheels on the ground. In an independent front axle application such as Toyota uses on the 4Runner and Tacoma, when an obstacle pushes one front wheel upward, the vehicle is lifted but there is no pressure exerted on the opposite front wheel because it is independent of the other front wheel. Same principal applies to the rear wheels.

You can see this in action when you view videos of vehicles negotiating moguls. The solid axle vehicles will keep both wheels of the same axle on the ground much better than the vehicles with an independent front axle and it is particularly noticeable when you see the demonstration with a Cross-Over vehicle that has 4 wheel independent suspension. The Cross-Overs lift tires way more frequently than vehicles with solid axles. It's because the independent suspensions are working each wheel independent of the other wheels. Solid axles work both wheels as a unit..

Note that Jeep has used solid axles on both the front and rear of some early Cherokee models which were uni-body construction.

Cheers,

Bob

 

You made it clear to me, thanks

 

It's independent suspension that has little flex, unibody has nothing to do with it. The only reason why unibody comes into play is because most crossovers are unibody construction. On the other hand, look at a unibody Jeep Cherokee XJ, that thing will put any flex you got from your 4Runner to shame.

And really, the 4Runner doesn't articulate all that great. The rear is pretty good because it is a solid axle, however the front doesn't really do much. Watch videos of Toyotas in challenging situations, they lift front wheels a lot as well. Most crossovers have the same issue in the rear, because they're independent there as well. And you are correct, the articulation of the defender sucks. Once again, it's because it has independent suspension at all four corners.

Also, look at a late model Chevy Tahoe or Ford Expedition. Those are both full frame vehicles, however they have front and rear independent suspension with very little articulation.

Solid axle suspension provides the most articulation. That's why Jeep Wranglers and XJ Cherokees and (ZJ/WJ Grand Cherokees) have such great suspension articulation, because they are solid axle front and rear. That's why you hardly ever see anybody doing extreme wheeling with IFS Toyota's, because the solid-axle vehicles are much more capable. Solid axle vehicles are also generally cheaper and easier to lift, with most lifts also increasing wheel travel, unlike most independent suspension lifts.

I used to have a 97 Grand Cherokee, which was a unibody with solid front and rear axles. It had much more articulation than my 4Runner does.

The reason most manufacturers switched over to Independent suspension, in the front, then then the rear, was for ride and handling. They typically ride and handle much better than a solid axle rig. It's why people say their 4Runner handles and rides better than a Jeep Wrangler, and why say a Highlander rides and handles better than a 4Runner.

For manufacturing purposes, which ultimately comes down to speed and cost of production, the unibody is cheaper and easier produce, while being lighter and stiffer, which will help potentially with fuel economy and ride comfort.

 

You know even the Bronco which is advertised as the Wrangler killer, has independent front suspension

 

It does. I consider it a4Runner killer, but definitely not a Wrangler killer. The Wrangler is still ultimately the more capable vehicle, even more so once you start modifying it. The Bronco is still a good alternative with probably 90% of capability stock, having 35 inch tires right off the showroom floor and the front locker is a big help in that.

I think that for people who either don't want a Jeep Wrangler for a specific reason, or think that maybe it's a little too hardcore for them, the Broncos will be a great alternative. And I've actually seen videos, the Bronco looks like the front end has a pretty good amount of articulation for an independent suspension vehicle. It has an electronically disconnecting front sway bar, that seems to make a visible difference in performance.

Also, don't necessarily believe everything you see in marketing. Look at Subaru, they Market their cars as being off-road vehicles, and we all know that that's not true. You're more likely to blow the CVT transmission off roading than anything else.

 

Is it possible to modify the 4Runner and add solid front axle?

 

Absolutely! A good fab shop with knowledge of suspension should be able to do it no problem. I know of at least one solid axle 5th gen 4Runner, they also added a 5.7 V8 from a Tundra. RSG off-road in Colorado built it, they call it the T40R, because it's on 40 inch tires.

Also, I recently watched a video by The Fab Rats YouTube channel, they've converted a few Toyota Tacomas to solid front axle. They did it on their own shop truck, and on a customer's vehicle. If I remember correctly, they said the cost to the customer was about 10 K.

 

I will do that once my 4Runner is 10 years old. I will turn it into a monster

 

Here's a shot of the RSG T40R in action. Check out that front articulation! That's what a solid front axle will do for you.

 

What the hell

 

Pretty sick, right??

 

That cannot be a daily driver. Now I understand why manufacturers stopped making solid front axles

 

Pretty sick, and that's what you call a real off-roader

 

By then you will realize that you don't need a solid front axle.

Or, if you're doing stuff that does require a solid front axle, you're not going to want to do it in a vehicle that you drive daily.

 

The bug, has bitten. Puts a smile on my face

 

Gas prices are getting pretty bad, 4Runner will not be a daily driver anymore when gas prices will be like $8 a gallon. We will need a prius for daily driving That is when we should put solid front axles, and turn our 4Runners into beasts that will be kept parked and taken to the trails once in awhile, at 10 mpg on the highway making as much noise as the Russian Tu-95

 

I hope to do something more extreme with mine, eventually. But, that's 2 cars down the road.

 

You don't need a solid axle for good articulation.

As @surfermonkey stated, it mainly has to do with pivot points. To get the pivot points in the center of your car and your wheels to articulate like this on a daily driver, you would loose a lot of cargo space.

There's also the fact that solid axles are stronger, cheaper to build and are generally better for towing and hauling.

Daddy longlegs is a perfect analogy @Moon Landing !

 

Now that's what they call 'High Stepping'. Love it!