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Discussion Starter #61
Yeah I am interested in portals so I can gain ground clearance with the lifted style knuckle and not have crazy cv angles.

I already designed a 4x4 tacoma kit with TVs that cycles 18inch of travel. But at full bump ground clearance is limited. A portal would add 4inch or more of clearance and allow me to move the diff up a bit with lower cv angles and keep the travel.
 

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Yeah I am interested in portals so I can gain ground clearance with the lifted style knuckle and not have crazy cv angles.

I already designed a 4x4 tacoma kit with TVs that cycles 18inch of travel. But at full bump ground clearance is limited. A portal would add 4inch or more of clearance and allow me to move the diff up a bit with lower cv angles and keep the travel.
Wanna let me know what the sticker price is on that kit so I can appreciate my beams.:laughing::flipoff2:
 

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Maybe instead of traditional portals it would be more worthwhile to look into the "axle shaft is the kingpin" type of setup like a lot of 4wd tractor front axles use. Tire size and horsepower ratings check out. They might burn up at speed though.
 

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Maybe instead of traditional portals it would be more worthwhile to look into the "axle shaft is the kingpin" type of setup like a lot of 4wd tractor front axles use. Tire size and horsepower ratings check out. They might burn up at speed though.
Wouldn't you still need some form of bevel gear arrangement to transfer the power down the kingpin and to the knuckle? Once again it seems pricey.

Kevin
 

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Wouldn't you still need some form of bevel gear arrangement to transfer the power down the kingpin and to the knuckle? Once again it seems pricey.

Kevin

Yeah but you could hopefully design around an existing and cheap bevel gear pair from an open diff for a large vehicle.
 

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Yeah I am interested in portals so I can gain ground clearance with the lifted style knuckle and not have crazy cv angles.

I already designed a 4x4 tacoma kit with TVs that cycles 18inch of travel. But at full bump ground clearance is limited. A portal would add 4inch or more of clearance and allow me to move the diff up a bit with lower cv angles and keep the travel.
In the pic you're already giving up about 4-6 inches of clearance through the area of the control amrs just from the way the lower control arms are designed. I get the reasons for wanting portals. But isn't it easier and cheaper to at grab the low hanging fruit first?

You can see how much more you get on Front Range's setup:


I think the key problem you're going to run into is that it's basically impossible to both go-fast and have big heavy portal boxes out at the wheels. It's an enormous amount of unsprung weight if you're going to make them strong enough to handle much power. A mog portal box is what 150lb? Keeping the weight down requires at a minimum the portal assembly be integrated into the spindle/upright assembly. Even the relatively light weight H1 portals are 80lbs.


As far as cheap portals - I don't think you can find anything cheaper than the H1 portals. The last auction I watched had an H1 complete with a blown engine for $600 - for the whole thing. I'd bet you'd get your $600 back in aluminum scrap from the body and have the boxes for free. But... you've still got to do all the work of getting it, etc. And you still end up with the reverse rotation problem.

Or if you were wanting a production run - there's probably a dozen factories in China who can custom machine any gears you want and fabricate any housing type you want. I'm sure they could clone a mog portal axle for example. Sometimes it's less expensive than you might think. You could potentially even just design a custom spindle assembly that uses H1 portal gears in a different configuration with 4 gears per side to reverse the rotation back. If it were me - I'd start by sending some drawings to a CNC specialty shop like Dongguan Xiexu and see what they could come up with as a suggestion. Design the boxes around OEM wheel bearings or similar so you can use off the shelf sealed bearings. I'm sure there are some other sealed bearings that are smaller OD that could work better.

The other place I'd consider looking for gears if you want off the shelf gears is in various transmission or transfer cases. You'd probably need to double up the gears for strength, but that's another option if you're wanting to fabricate your own portal box. I'm sure there are some transfer case gear combos that could work.

There is also a German tractor but I can't remember the name of it that runs portal boxes. Smaller than a Unimog. But I'm not much help because it's been a few years and I don't remember the brand.

One other really outside the box idea here - you could run a variable angle gear hub to change the CV angle. You could build one from a standard differential center section that offsets the CV angle by 15 or 20*.

Or an alternative version of that - use very heavily positive offset wheels, push the hub way outboard, and just use that extra axle length as a way to reduce the CV angle.


I love the idea of portal axles. It's just so damn hard to make one really work well and be even remotely economical. Good luck with whatever you end up going with!
 

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Discussion Starter #68
I'm designing a new kit with high clearance lower arms like above as well. One issue with that is lca that you have to really clearance the frame at lca pivot to gain up travel if the lca doesnt have a downward bend in it. Also when adding high clearance bend to lca the shocks now mount higher up into the engine bay and in the way of brake booster and master cylinder. I have ways around both of these and will be getting that kit going next year on my 4runner build.
 

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Very cool. Can't wait to see what you come up with.

Possibly there's a solution where you use adjustable height air suspension to work around the CV problem. Run at moderate height most of the time with the ability to max out the ground clearance for short distances at lower speeds. It's kinda the Lexus / Land Rover solution. But the idea has merit even if it's not really common in the aftermarket.

Since I'm randomly throwing out other ideas - if you're re-building the coilover tower - it could work pretty well to design around a Raptor front coilover. They're pretty great OEM coilovers and they're dirt cheap. If you were planning to sell aftermarket parts to the Toyota community, the ability to run Raptor takeoff front suspension parts could really help reduce the cost of entry. Avoiding the cost of custom length coilovers could go a long way toward selling them.

Good luck!
 

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Very cool. Can't wait to see what you come up with.

Possibly there's a solution where you use adjustable height air suspension to work around the CV problem. Run at moderate height most of the time with the ability to max out the ground clearance for short distances at lower speeds.

OffRoadOnly makes the AirRock system, which could be worked into this idea.
 
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