Tube/Hybrid Stretched 40 Frame and Suspension Design - Advice/Comments?

[DirtSniffer]

lol show me in real world

Give me a few months . I am also not 100% set on what axles I am using but I am leaning heavily towards the RuffStuff. I may, however, need to run a smaller front diff for the panhard to clear the crank pulley if I can't more stuff around enough. Still some things to sort out.

 

[Ditcherman]

Give me a few months . I am also not 100% set on what axles I am using but I am leaning heavily towards the RuffStuff. I may, however, need to run a smaller front diff for the panhard to clear the crank pulley if I can't more stuff around enough. Still some things to sort out.

That's an interesting way to prioritize, when you consider you are building a frame from scratch, to accommodate everything else you want.
Why let the panhard and crank pulley dictate the size of the diff? Can the panhard not move forward a few inches or down on the frame side to clear?

 

[DirtSniffer]

That's an interesting way to prioritize, when you consider you are building a frame from scratch, to accommodate everything else you want.
Why let the panhard and crank pulley dictate the size of the diff? Can the panhard not move forward a few inches or down on the frame side to clear?

I don't have the engine model nailed down quite yet and need to work on the front end more, it's looking like the current bar position will be into the crank pulley a bit at stuff but I need to confirm. If so, yeah I am hoping I can move it forward enough. Or engine back some. But I can only move the engine so much. There will be a 40 near me with a 606 in it for me to take measurements off soon enough to get a better idea. Could also move axle forward a bit.

 

[DangerNoodle]

The rear looks fine. You don't need any more ange on the uppers or lowers. With a dual triangulated four link, there is almost no way to cause axle lateral movement unless there is only a few degrees of triangulation. I feel you are overthinking that part and will be compromising on other sections that matter more.

 

[DangerNoodle]

And with a offset rear you will run into issue with the links hitting the driveline

The neat thing is that if you put the lowers and uppers in a relatively similar location to the joints on the driveline, they move as a system. Unless you are getting into moon buggy territory, you probably won't have links and drivelines cross.

 

[DirtSniffer]

The rear looks fine. You don't need any more ange on the uppers or lowers. With a dual triangulated four link, there is almost no way to cause axle lateral movement unless there is only a few degrees of triangulation. I feel you are overthinking that part and will be compromising on other sections that matter more.

Appreciate it. I'm going to do some more reading up on link geometry before messing with things any more. But wanted to get some brackets plopped on to get an idea of how things looked as it sits.

 

[Firemedic831]

The neat thing is that if you put the lowers and uppers in a relatively similar location to the joints on the driveline, they move as a system. Unless you are getting into moon buggy territory, you probably won't have links and drivelines cross.

The blue 40 has the proffitts rear 4 link and the links definitely hit the driveline .

 

[DangerNoodle]

The blue 40 has the proffitts rear 4 link and the links definitely hit the driveline .

I did add some stipulations in there lol. It's definitely possible to have it hit.

 

[Mike Shull]

Get the plasma fired up already…

This thing is going to be cool. I may have missed this but are you planning to drive it on the highway?

 

[Mike Shull]

… Unless you are getting into moon buggy territory, you probably won't have links and drivelines cross.

I had to research what a moon buggy was used for…

 

[Ditcherman]

I don't have the engine model nailed down quite yet and need to work on the front end more, it's looking like the current bar position will be into the crank pulley a bit at stuff but I need to confirm. If so, yeah I am hoping I can move it forward enough. Or engine back some. But I can only move the engine so much. There will be a 40 near me with a 606 in it for me to take measurements off soon enough to get a better idea. Could also move axle forward a bit.

Ok, but to put a finer point on my question, how much do you trust that you can take a fairly rudimentary drawing and go out to the shop and build it and it will not need modifications? I'm just saying I was surprised to read that you might make a decision on an axle/diff based on a computer drawing.
Now, maybe I'm reading too much into that, and I'm certainly only trying to offer encouragement, not criticism, because your build has the potential to be the perfect linked 40 suspension/frame/engine/body.

I'm sure my build has been hindered by the fact that I am only wiling to scribble emergency problem solving on scrap pieces of paper as the emergency unfolds, literally standing there with the plasma in one hand and the welder in the other thinking "now where should this go?" I've build enough stuff to believe that to plan ahead in great detail with a basic drawing and assumptions eventually (quickly?) and turn in to a rabbit hole that is actually giving you wrong info.
But that's more just me, I think your plan is very cool, I'm just encouraging you to not make too rash of a decision based on a drawing where you don't really know all the true inputs, when you can go to the shop and figure it out, which you will do anyway.

I'm very excited to see this come together.

 

[Ditcherman]

I had to research what a moon buggy was used for…
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Do you think those astronauts were like "50 bazillion dollars and all we get is a lawn chair?!?"

 

[Mike Shull]

Do you think those astronauts were like "50 bazillion dollars and all we get is a lawn chair?!?"

I’ve had similar thoughts about my project.

 

[DirtSniffer]

Ok, but to put a finer point on my question, how much do you trust that you can take a fairly rudimentary drawing and go out to the shop and build it and it will not need modifications? I'm just saying I was surprised to read that you might make a decision on an axle/diff based on a computer drawing.
Now, maybe I'm reading too much into that, and I'm certainly only trying to offer encouragement, not criticism, because your build has the potential to be the perfect linked 40 suspension/frame/engine/body.

I'm sure my build has been hindered by the fact that I am only wiling to scribble emergency problem solving on scrap pieces of paper as the emergency unfolds, literally standing there with the plasma in one hand and the welder in the other thinking "now where should this go?" I've build enough stuff to believe that to plan ahead in great detail with a basic drawing and assumptions eventually (quickly?) and turn in to a rabbit hole that is actually giving you wrong info.
But that's more just me, I think your plan is very cool, I'm just encouraging you to not make too rash of a decision based on a drawing where you don't really know all the true inputs, when you can go to the shop and figure it out, which you will do anyway.

I'm very excited to see this come together.

I certainly appreciate constructive criticism and am not taking your comments as anything else. That's the reason I started this thread, so people can call out issuing in my thinking or suggest better solutions.

While my model may be a bit crude, it is close enough to determine things such as transfer case output locations, overall driveline length, driveline angle, transfer case clocking, etc. so I can determine pretty closely where everything will sit and see any obvious interference there will be with the frame, axles, links arms, etc. I'm sure there will be some alterations once building things for real, but if I put enough effort into planning ahead they should hopefully be pretty minor. I did not initially put any time into the front of the engine because I thought the oil pan would be the main concern for interference with the axle and panhard/steering linkage. But I'm now seeing that's not the case and that I need to spend some more time on that area to make sure I won't run into an interference issue with the crank pulley.

 

[DirtSniffer]

Get the plasma fired up already…

This thing is going to be cool. I may have missed this but are you planning to drive it on the highway?

That's the plan

 

[Mike Shull]

Bit of link development. I am going off the general rules of axle link separation = ~25% of tire diameter, and top link length ~75% of bottom links. I think I will be running a CV rear driveshaft, so I have the rear diff pointing up about 10* to try and keep it out of harms way which points it pretty close to the T-case output. I have done the same for the front, but I am playing with the idea of using a fixed driveshaft carrier about 1 foot forward of the front output to avoid having to cut a notch in the belly plate. May not be worth it, just playing around right now. I have determined that unless I am ok narrowing the front axle bottom link mounts, I will need to widen my WMS to 66" to keep full steering lock angle as the tires will hit the links if narrower (Assuming about a 5" scrub radius?) . It would probably be fine to narrow the front bottom axle mounts have a lower convergence (about 16* vs 22*) for the front lowers as it is a 3 link and the panhard will be dealing with most of the lateral force. I also think I need to widen the top frame mounts for the rear, not enough convergence. may slide that tube section forward and mount it underneath as I mentioned earlier and forego the adjustable bracket. I will say, its nice doing this in CAD (Albeit a bit crudely) vs doing this IRL and having to redo everything multiple times over.

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Also, might be getting a bit ahead of myself, but I think I might be able to squeeze a decent sized (about 18 gallons as shown), but funky looking fuel tank between the rear top links.

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This looks like good work, especially with the front end. I had to redo my rear coilovers mounts twice and I will end up inboarding my front lower link mounts at the frame so that I can clear (and potentially widen) my turning radius. I am still limited by my factory frame and bib at 63” WMS and I’m curious to see what 66” looks like on your truck. Who knows. I may add a few inches back to my width.

I totally understand the value in using CAD to help reduce rework. Perhaps it’s not time to get the plasma fired up just yet.

 

[DirtSniffer]

This looks like good work, especially with the front end. I had to redo my rear coilovers mounts twice and I will end up inboarding my front lower link mounts at the frame so that I can clear (and potentially widen) my turning radius. I am still limited by my factory frame and bib at 63” WMS and I’m curious to see what 66” looks like on your truck. Who knows. I may add a few inches back to my width.

I totally understand the value in using CAD to help reduce rework. Perhaps it’s not time to get the plasma fired up just yet.

DJ's 40 is at 66" track width and has a good looking stance. I was wanting to stick with 4" of poke past the quarters because genright makes some nice looking 4" tube flares that would be easy to modify to work for me and bolt right up to my 3/16 quarter panels. But maybe I should build my own flares.

 

[Mike Shull]

DJ's 40 is at 66" track width and has a good looking stance. I was wanting to stick with 4" of poke past the quarters because genright makes some nice looking 4" tube flares that would be easy to modify to work for me and bolt right up to my 3/16 quarter panels. But maybe I should build my own flares.
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I didn’t realize that DJ had a 66” wide stance. One of these days he will have to bring his Cruiser over instead of his Volvo.

My vote is to build your own flares if you are planning any modifications to what is available off of the shelf. Mine were very easy to make and I raised them up to the max to get a full 7” of up travel.

 

[DangerNoodle]

I didn’t realize that DJ had a 66” wide stance. One of these days he will have to bring his Cruiser over instead of his Volvo.

My vote is to build your own flares if you are planning any modifications to what is available off of the shelf. Mine were very easy to make and I raised them up to the max to get a full 7” of up travel.

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I'm at 63.5wms. Factory 80 width.

 

[DirtSniffer]

Maybe we should clarify our wheel offsets/backspacing? I was assuming 0 offset like a stock 80 so my WMS was my track width. Your track width was 66" on the link calculator.