Duramax IFS Suspension

[fl0w3n]

Shoot i thought you were throwing 2:1 out as an example and I forgot to measure it myself when I was playing with it yesterday. Good point.

Well if that’s the case, then those 6.5” stroke may be very close to working with the stock tower and an UCA. With 17” extended on stock UCA and stock tower I probably wouldn’t even need to remove a 1” spacer, not sure what the Camburg arm will add though.

like you said I need to make sure of the compressed measurements though. I plan on taking it without the jounce stop in place, figuring that’ll give me absolute worst case and that in most situations it’ll actually be even less because the stop will take up some of that travel. But I don’t want to risk blowing the top off or bending the shock tower.

 

[Chevy1925]

2:1 is not spot on but its close enough. its served me well on all my calcs ive done.

You can get the torsion bar out by putting a jack under the LCA at full droop, loosening the adjustment bolt all the way, pop the UCA out of the knuckle and then lower the LCA and knuckle down till the torsion goes loose. i have a torsion tool i have not used in quite a few years because i wind up just doing this method. usually im in there replacing front end parts anyhow if the torsion is coming out.

btw, if you order these shocks from fox, ill make a valving suggestion. I would start with a #50 on rebound (straight .012 stack) and id go higher than the #90 they send. i start with a .020 stack with a flutter (.90 dia shim, .010 thick between the largest dia shim and sec largest dia shim on compression side). ask if they are 1 or 2 bleeds open and start with 2 bleeds open. Once they show up, up the nitrogen pressure to 250psi (if you are not running clickers on the resi) and then go run her. that should get you pretty close. i would shoot for 60/40 in droop to bump ratio ( 60% bump and 40% droop based on wheel travel numbers) at ride height. that should be a good starting point that you can tweek from there on.

 

[fl0w3n]

Okay thanks for clarifying.

That's a good call. I got pretty good and fast at busting the torsions out on my 06 because I tweaked with it so much, I could do one side out in like 45min I think it was.
But... your trick might wind up working perfect in this situation. I'm a little backwards, but I'm thinking I need to order the UCA first and get it on there so I can get accurate measurements before commiting to a shock. The UCA was supposed to come later in the budget... but if I'm changing the UCA then your method will work perfectly. I also forgot I have a set of Kryptonite LCA ball joints that I never warrantied sitting in a box, so I'm going to get those going and put them in as well.
I may have to skimp on the rears right now and just go with the regular smooth bodies if I do the UCA and the more expensive remote resi's

I didn't know you could order direct, I was thinking of going through ORW and there is still an option for custom valving when ordering. I was thinking I'd just request the same valving that the "kit" for the 01-10 trucks come with, but if you've played with them then I'll go with your recommendation.

 

[fl0w3n]

It’s late and I’m tired but I wedged the Ballistic towers in there to see how far it’s off.

It’s not a mile but it’s not a home run fit either. I think a 6” or so diameter round plate welded to the top of the tower and partly to the frame, with two longer gussets down the frame side with this tower bolted on top of that could get the job done.
The question is, is that easier than just hacking the stock tower off and building a shock hoop. The whole point of this experiment was not to go that route, and just “massage” some more travel out of the stock setup. If I’m hacking the towers off I might as well let the grinder slip and take it all off and do an 05+ SD60 on Carli coils and shocks.

 

[fl0w3n]

Lol... so maybe I can see just how many dodge parts I can stack up to make a Frankenstein system...

I found they make shock tower delete kits for the dodges. Well, that sounds perfect because that means there’s a plate with a shock stem hole spaced out correctly from the three tabs/holes for the shock tower.
I could weld some studs for the three tower tabs, and then use the stem hole with a temporary bolt to go through the Duramax shock stem hole so it’s correctly lined up, and then weld the “delete” plate to the tower.

only problem is afterwards that’s some thick material to cut through without a plasma, and the plate isn’t wide enough to work any gussets into.

maybe I could just use it as a template to trace

 

[Chevy1925]

i personally say, let it slip and put a LSK kit on there

 

[fl0w3n]

Who is LSK, I hadn't heard of them until they recently showed up on Dmaxstore.

Not that I value myself as so important as having to know everyone lol, but I've been hanging around Dezert Rangers, RDC, Pirate etc for the past decade and a half and I know the options for the 4wd trucks whether 1500 or 2500 have always been slim pickings.

The "problem" I see is it still only uses an 8" coilover, which in my limited understanding, only provides single rate spring and while certainly better than torsion, still isn't as good as a dual rate.

Have you heard of "Tim's kit" from Pirate? For that type of money, I'd like to do a mix of Tim's cross member and arms, with WFO's new coil bucket towers, and Carli F250 coils/shocks



"leveled" on 35's vs the SAS kit he designed on 37s

 

[Chevy1925]

you honestly dont want a dual rate. even a 10" only uses a tender spring on top. you are too heavy and cant run ENOUGH spring to even think a dual rate will be beneficial. even still, i run a 16" spring over a 14" spring on the back of my tracker and i wish i could run a 20+ inch spring with a much shorter spring above it. you get a much better linear rate. makes valving work better and the chance of "over rebounding" the suspension because you over powered the rebound valving from the secondary collar on the bottom spring being too far down is much lower. if you ran a 2.5" coilover and do the conversion to run a 3.75" coil spring, you gain sooooo much control over spring rate, more spring rate at block height and a setup that works better than the kibbetech truck and others like it (you could actually set the front end to sit a little higher than most i see which is needed). dont get hung up on dual rates. its old tech that is good for rock crawlers these days. Barge on dezert rangers will give you a full explanation on that as well, even more so than i am. that sum bitch is a smart cookie on shock tuning.

LSK is out of cali, they make a 1.5" over kit that pulls 13" of travel IIRC. They have been around for a long time and made this kit about 4-5 years ago. otherwise Kibbetech is the only other one i know making kits and they aint cheap. might be more ive not looked into.

ive seen Tims kits, they are nice!! just remember, if you plan to bomb this thing off road, set yourself off to have 60% or 50% min down travel at ride height. this can be an issue on straight axle kits while keeping low ride height.



i dont wanna sound like a debbie downer but anymore, while you can make these trucks work pretty well after you do all this work, its still not the same as a 1500 with a proper long travel kit. the front end weight is killer in these trucks and makes it REAL hard to get a good balance and valving off road.

 

[fl0w3n]

Interesting, I definitely have a lot to learn still. I may pickup some books on basic concepts, just for fun. Like I first said, I tend to over analyze haha

I used to work right next to Kibbetech, I saw Dunewhore's truck there a bunch of times when it was getting built. Kibbetech "built" my bump stops on my 06 now that I think of it.

Your debbie downer comment is exactly my point actually. I am looking for relatively easy ways to tweak just a little bit more out of these trucks, at least "easy" when compared with a full long travel kit or SAS. That was my idea with the dodge shock tower and extension, thinking it would be a trick way to get more travel and be able to have more tuning into just a basic shock package and better compensate for the super stiff spring rate from the torsion bars.


To be honest, my truck will primarily be a pavement pounder, so comfort there is critical. My old 06 LBZ was like a dream at 85-90 MPH, no bump steer, great small bump compliance, super predictable in bumpy corners, no hands at 85 (albeit dumb). But I don't want to spend money on a lift kit again, I only did on that truck because I bought it lifted. Its secondary use would just be cruising back roads and full width easy trails.

I originally bought my 02 ZF6 with the idea I'd do a SAS and make it a robust all around wheeler/adventure rig, but eventually talked myself out of that $$. What better fits my needs right now would be a mild setup on my 04 and an XJ on a trailer, either with a slide in camper or a crawler hauler setup. As much as I like to drool over them, I'm realistically not going to spend my time bombing whoops and desert like the Carli or Kibbetech trucks right now.

Realistically, I'd probably be happy enough with just the Camburg UCA and the shocks that come with it, but I can never leave anything alone. At the minimum I'd like to pull my own measurements and see if I can get any better fitting 2.0 IFP in there. I'll probably keep playing with the shock tower extensions and if I get confident with it and pull the trigger, I'll consider going 2.0 remote or even 2.5 at that point. Only reason I'd consider 2.5's is because with the weight of the front end I don't know if I'd heat 2.0's up enough from a day of cruising fire roads.

 

[fl0w3n]

Due to time and desperately needing new shocks I just went with the Fox 2.0 984-24-663 & 664 for “0-1” lift applications.

eventually I’ll pickup the Camburg arms, deaver mini pack, and install the kryptonite lower BJs I have sitting. When I do I’ll take more measurements and start mentally masturbating again lol

 

[fl0w3n]

Oh and I have the fronts on, didn't have time to do the rears before the 1200 mile road trip last weekend. Much better on-road.

I have another 600 mile on-road trip this weekend, and the following weekend another 1400ish mile trip with about 60-70 miles on mild trails, so I'll really get to see how they do then.