Best roll cage, tube frame/chassis for weight loss?

[v7guy]

Bill, what is this solid axle front thing you mention?

I couldn't see the point of doing anything serious without kicking the front axle center line forward. When you take into consideration that even 35s can hit the firewall it just makes sense. In addition you effectively move chassis weight rearward and make your approach angle drastically better.

By the time you realize this point you recognize you're starting from scratch. The stock pickup points don't really work anymore. The diff needs to move forward, the shock towers need to move to accommodate the change and the longer travel coil overs... basically everything just goes to hell as far as stock is concerned.

I can think of a few ways to do long travel IFS within the confines of the stock subframe with a rear sump pan. You could probably even just lengthen the stock a arms and CV shafts and get some really good travel out of 33s. Positioning the rack might be interesting, but maybe doable if sufficiently motivated. I've been thinking about it on the envoy as a stock based system.


But as you turn it over in your head more you realize that you kinda got to start from scratch. We got some decent bumpsteer lifted as is. When you're looking at making a new subframe, a arms, etc, bump steer is the least of your issues. It's some nice icing on the cake. But it's easily dealt with... and you're still gonna have some at the extremes.


Eventually you're going to crunch the numbers, agonize over everything and then you're going to build it and then the real world will creep in and everything will be off to some degree or another. I gave up and decided to build it all from scratch copying many guys before me. I got a little hung up initially trying to make the suspension deliver the best travel numbers and after some correction on various boards, I realized they weren't doing anything special and they were just treating it like the tried and true road race car suspensions I was already familiar with.


I completely gave up working on stock suspension and just decided to build it all. There's a lot of merit to using stock components. I chose to go with .25 and .50 steel for a new spindle. It's as heavy as your average walmart shopper using a motorized cart, and it's not optimum in any way, but I'm confident it'll hold up. The hub comes from a 3500 chevy with an ABS reluctor ring that is the same count as our lowly trailblazer. We'll see how that translates.


In the pic the steering mount will be added last.

Was just made aware the picture was clipped...

[fishsticks]

This is what happens when I leave for awhile...

[Regulator1175]

There is only one thing I have to add to this thread.....

[ErikSS]

Dude man, that's like some crazy serious Off Roading and stuff!

[Nakashige]

I should be cutting mine up soon

[ErikSS]

I should be cutting mine up soon

Looking forward to that thread!

[AWCougar]

As far as control arms go. Do you guys think that 1 5/8 chromoly tubing for LCA is a little overkill or about right?

[Nakashige]

As in manufacturing LCA for a TB IFS?

[AWCougar]

Yeah. Like dry sump oil pan new front diff and longer control arms

[Nakashige]

What are you going to use for a front dif

[AWCougar]

Im thinking just the 7.2 out of a suburban or something haven't fully decided. Still open for suggestions

[Nakashige]

Well the 7.2 in a Suburban does go through a oil pan

[bartonmd]

FWIW, the 1/2 tons have an 8.25" (the dirty one) and the 3/4 and 1-tons use a 9.5" front end (the clean one). The passenger side bolts on, so maybe make something to shorten that side and take the splined disconnect out of it?
http://www.pirate4x4.com/forum/chevy/10 ... 0-ifs.html


Otherwise you'd almost have to do a bare D44/D60/9" housing or something, like the Ultra-4 guys do. The 3/4 and 1-ton IFS stuff in the front end of most trucks actually goes end to end, and has the longer housing on the passenger side, so you can'd do longer half shafts unless you go wider, then you're not in much better position than you started.

You can take a solid axle and shorten it:



Or, you can buy one like the Ultra 4 guys use:
http://www.lowrangeoffroad.com/spidertr ... fs001.html
.

http://www.currieenterprises.com/cestor ... px?id=3498




Mike

[v7guy]

Chris, Barton is pointing you in the right direction. I wouldn't bother with a 7.2. It's small, it'll break. The GM 9.25 IFS front diff is a good cheap option, you can narrow it, there's a front locker available for it. The 2012+ front diffs have a stronger case, but they're still pretty expensive and it's why I went with the clamshell case. You can also get this to eliminate the disconnect http://www.dieselops.com/fleece-perform ... 0-4wd.html

The problem you run into while narrowing it is that you're now raising the truck pretty high to place the diff under the motor even with a rear sump/dry sump pan. My diff has the upper mount shaved off, a new mount built up front, and the oil pan bottom is a bit less than 3" deep, just enough to clear the caps and the pickup tube (the same as with a dry sump). If you place the diff in the center you're gonna end up dropping the diff down another 6" or better. Not to mention you have to snake the driveshaft around. Even with my setup I'm a good 3" lower from stock measuring the axle centerline. You could have it sit lower and gain more travel, and that may meet your needs depending on what you're doing, but eh, I didn't see it helping me.

Keep in mind a lot of the trucks with long travel are in the 85"-87" width range or more, basically as wide as a full size SAS, so you've got room to work with.


Concerning lower a arms... you might as well build em outta balsa wood glued with chewing gum if you're looking at tube. There's a reason all the long travel LCAs are made out of plate, they're gonna hit shit. Also Chromo is a waste if you can't TIG it. It's only useful because it's as strong as mild steel but at a reduced thickness. So it's lighter. For the average garage guy on a budget it serves no real purpose. Just use some mild steel that you can easily MIG and call it a day.

[HARDTRAILZ]

Fleece is local to me...kinda. Many people send their diesels there to get built around my area. With the power numbers they produce I bet the disco elim is a stout unit.

[AWCougar]

I will be doing a 14 bolt full size 86" rear with 85" front
through the entire project I have learned a lot so far. The biggest and best thing that i've learned is, geometrical design sucks lol the other thing is time I need time and I work 60 - 65 hours a week. Not including side work.
all the info is awesome I have been using pirate 4x4 for a lot of it as well as other sites. Most times the info seems very overwhelming.
but I can't thank you guys enough for helping me out