So, with 4-wheel independent suspension, how would you configure the drivetrain? A centrally located diff. with driveshafts running from it to what, extra pumkins or something??

 

think of 4 wheel independant as being the same as any other 4wd vehicle, just the rear is independant like the front instead of a solid axle. you still have 2 driveshafts, and 2 diffs, the suspension is just configured differently.

 

This set up would likely make and excellent desert runner. You would, however, want to use a trailing arm set up in the rear as opposed to a double wishbone like is in the IFS trucks.

The on road ride would likely be excellent as well. I find my front suspension absorbs bumps very well while the rear does not do so as well.

IFS/IRS does not take advantage of the leverage characteristics which apply to a solid axle. However, the lower unsprung mass means the wheels need less dampning and can change direction much faster than a solid axle.

Frank

 

I've seen it done with a Dana 44 or maybe it was a 60 center section

 

A front and rear Independent might be cool in a 75-80" quad/buggy type deal. narrow the frame a little, total chaos all around, coil-overs, single seat. I have a pretty cool mental picture..... sort of a super sized king quad....

Keep the weight down for sure

 

I was thinking of it for my 88' 4runner. I was thinking of an awesome handling daily driver, plus a backroad burner. Maybe for a trip to Baja.

I was wondering if you could take the complete IFS and turn in backwards for the rear. All of the driveshafts would be the right direction. And of course torsion bars set up for the rear. Not thinking of rear steering or anything like that.
Total Chaos front and rear for great handleing and a wider stance. It seems like it would be a crazy fun ride.

 

I believe these use a type of irs . I hope to own one of these in a year or so

 

You certainly could turn the front ifs around for the rear of the truck but you would not want to go with the wish bone suspension. Trailing arms are much better.

The reasons have to do with the direction the suspension travels and initial impact as well as trying to get the best travel in a given amount of space.

Even notice how spint cars and other off road higher speed vehicles have front wishbone suspension that is angle back? That is because when you hit a bump, you are not just pushing the tire up, but back too. This way, the suspension is reacting the direction it is being pushed which makes it react better.

For the rear suspension, trailing arms do the same thing. At first impact the tires start to swing rearward and up in their arc. As they continue, they swing more upwards. You could try to use angled a-arms in the back but the truck will try to rise/squat when you forward/reverse it. Hummers make it work but they have very stiff springs.

Frank

 

I know that the 2nd gen caddy gets rid of the torsion bars for the IFS. I wonder what I would need for the rear? Could I go without the torsion bars in back?

elripster: I am not sure exactly what you are saying about the trailing arms. What I am trying to say is, I am not sure how the trailing arm works. Could you please explain how it works, or maybe a vehicle that has it so I can look under it?

Thanks
Kent

 

A trailing arm is basically a swing arm. Most buggies have them as well as many other vehicles.

The arms face rear/downwards. Of their arc is actually angled similar to a Mercedes so the camber comes in when the tires are compressed.

Here's an example of a smaller trailing arm setup.

Here is another picture of what you would more likely want on your truck.



You can get lots of travel with fewer moving parts using them. This is especially helpful since the rear frame is wider making longer a-arms more difficult to implement.

Frank

 

elripster:
Thanks, Now i know what it is and recognise it. it also helps me understand bout why I would need it.
that kills the idea of total chaos all around then, unless they hafe atrailing arm ret up too.

Thanks

 

If you were serious about this, let an aftermarket outfit take care of the front, the geometry is much more complex/critical.

You can fab or possibly even find buggies or other vehicles with the parts you'd need to put a rear suspension together.

It would probably be really expensive but while we're dreaming, who cares!

To be honest, many a shop could build you a custom IRS. It's really all about the cash.

Frank

 

Just to put in my 2 cents. For desert racing, trailing arm setups have been highly favorable to a-arm setups in the rear. People have tried a-arms and then hacked them off to do trailing arms. It just works out much better.

 

Like my daddy used to say: " you can do anything, all it takes is time and money. If you got a lot of one, you don't need as much of the other"

All I can say, To do this, I would need A LOT of time!





But in all honesty, it seems like using a trailing arm would make this even more likely to happen. It seems like fabbing up something for the back would not be as complicated as I first thought. I'm not saying it would be easy, but al least easier than doing the "IFS turn around" I thought of earlier.
There are a couple of buggy places around here. I should go around and look at thier set-ups and talk to them about my truck.
I have to admit, if I could do this, I would. If only to have something totally different. But I also like to drive fast off road in the back hills, and I think IFS+IRS would make my 4runner a ton of fun for me.

 

It would be cool if you pulled it off. You can still wheel some pretty hard trails with a locker so it's not like your truck is only good for one thing.

You would have something unique and that is always cool.

Frank

 

In defense for the mil spec hummer.....I have been to hummer school and the frist thing they tell you there is to do your best to not get it air borne......they have lots of vids there about hummers going air borne and breakin when they touch back down. They simply weigh too much, the sus is at the end of its travel and the frame is not touching. You can get away with not breaking them going airborne and then landing in soft sand or mud. I later tried it in some mud and had to get a Brad to pull the damn thing out it was stuck so bad.......I talked to a bunch of the mechs with 25th trans ROK and they say the hummers will climb just about any thing and if they have the river kit installed will even run more than half under water and keep right on pulling, but you get two tires airborne and it will break 8 times outta 10, not bad for trucks...but they ain't air planes.......

 

On total chaos website, it show a few fully airborn trucks. Of, coourse they don't weigh as much as a hummer, but very cool. I don't think I will be geting too airborne myself tho'


I am making my own roof rack for my truck, with a different kind of mounting. I don't want to drill into my fiberglass roof. As soon as I am done with that, and making my own bumpers, I think it will be time to start on project "screw up my truck!"

 

What interesting about this is I have seen many pictures of hummers jumping and survinving very well. There appeared to be Military versions owned by civilians. I gues they must have lightened the load or something.

Frank

 

Probably just don't show the "after" photos...

 

when i said that i have "IFS Rear" i meant that i have a rear axle out of a 86-95 truck which is 3" wider, it came out of a IFS truck, so thats why i call it a "IFS Rear"