Future of KOH 4400 chassis/car development?

SLOWPOKE693 said:
It's different but proven to work much better than the old design, so it must be a decent idea.
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Better than the old version isn't saying much. It's still not great. The main things it's got going for it are lack of lateral scrub and low bumpsteer. Both of those could be accomplished with some camber gain to give it better cornering grip.
 
snivilous said:
It's interesting on Cole Clarks buggy how it still has radius rods instead of a Class 1 style trailing arm with two chassis mounts. I thought the desert guys considered that superior geometry wise and there's no toe change. Maybe he thinks it's more likely to get hung up? Also interesting he has two radius rods considering Can Am and now Polaris both have setups to try and alleviate toe change caused by a two radius rod setup.
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From my understanding, radius rods need more droop for the CVs, meaning they would have to be different than the front. Maybe he did it to use the same CV shaft at all 4 corners to reduce the amount of spares he needed?
 
bdkw1 said:
Better than the old version isn't saying much. It's still not great. The main things it's got going for it are lack of lateral scrub and low bumpsteer. Both of those could be accomplished with some camber gain to give it better cornering grip.
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The car you posted is strictly a crawler from what I've seen, so their probably isn't a set of class rules it had to be built to. He most likely could have spread the control arm mounts further apart on the frame and portal box side to help out with leverage but with it being a crawler, it looks like they were shooting for maximum ground clearance as opposed to the best possible suspension geometry. 🤷‍♂️

All the U4 cars I've seen that run ifs and portals look to have much more separation on both ends of the A arm (in scale) compared to that UTV.
 
So solid axles are bad because of lack of separation? While more separation is better and easier to work with, it's not the end of the world.
 
bdkw1 said:
So solid axles are bad because of lack of separation? While more separation is better and easier to work with, it's not the end of the world.
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I put far more vertical separation in my straight axle builds than that SXS has between those a-arms. On my version of GZR the lack of separation is a problem. The Pro XP made it have more and then the Pro R even more again. If I were building one from scratch it’s something I’d build in. That and make the two points of the a-arms further apart as well. My unit is hell on joints and a-arms.
 
HYDRODYNAMIC said:
Has anyone put a solid axle in a golf cart? Sounds like Ultra4 solid axle rear is better than IFS. With a custom frame is a solid axle golf cart possible?
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bdkw1 said:
Solid axle would end up stretching the WB a bunch. Even the Yamaha they did that too ended gain about 10" in the rear (giggity) and they have a semi sorta regular T-case location.
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bdkw1 said:
So solid axles are bad because of lack of separation? While more separation is better and easier to work with, it's not the end of the world.
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Yes. KP axles were not holding up to big tires and racing so Spidertrax and others started making fabricated inner and outer knuckles with a much taller height piviot to pivot to better deal with the leverage being placed on them. The new Super 60 inner C's are massive compared to a BJ 60 of 10 years ago so more separation is definitely better even in a solid axle application.
 
HYDRODYNAMIC said:
Has anyone put a solid axle in a golf cart? Sounds like Ultra4 solid axle rear is better than IFS. With a custom frame is a solid axle golf cart possible?
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I've wondered about that and not sure of a good way. I've thought about flipping the engine around and put it up front, and then the normally front driveshaft would become the rear driveshaft to a solid axle, and the CV outputs off the trans would go to the IFS. It'd spin backwards so put some 2 gear portals on and you're good to go.

I have a X3 that doesn't see much use so these ideas float around my head :laughing:
 
HYDRODYNAMIC said:
Has anyone put a solid axle in a golf cart? Sounds like Ultra4 solid axle rear is better than IFS. With a custom frame is a solid axle golf cart possible?
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Yes

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snivilous said:
I've wondered about that and not sure of a good way. I've thought about flipping the engine around and put it up front, and then the normally front driveshaft would become the rear driveshaft to a solid axle, and the CV outputs off the trans would go to the IFS. It'd spin backwards so put some 2 gear portals on and you're good to go.

I have a X3 that doesn't see much use so these ideas float around my head :laughing:
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You like to complicate your life it seems lol
 
SLOWPOKE693 said:
Comp crawler? I know one of their UFO's has some weird IFS in it like that.
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The Thompson/Gomez IRS has a dog bone axle in the center, and then one side has the offset diff. The dog bone center gives the car a lot of clearance in the center for fewer G-out hits (That hurt). The dog bone has a length in line with the arm pivots...similar to a IFS steering center steering shuttle. (maybe 12-14") The offset diff sits as close as possible to the tire, and allows the driver to put that corner on top of a rock to clear the diff obstacles. I think they have generally gone back to the double triangulated Rear SA with offset diff. (Rear motor so transfer case offsets the driveline to one side). Not new news here, but may bring others along.

I bet if we really looked close at slow crawl pictures...We would find that the SA would place the tire more flat to obstacles in articulation. AND much stronger when using the side walls for traction. AND turn 55*+ instead of a lucky 40* with that much IFS articulation.

IN the real crawl sections of KOH, the SA has been faster. Actually SXS's migh be faster because of the shorter wheelbases allowing sharper turning. BUT real crawl sections usually cause bottlenecks so generally avoided uphill by the promoter. (Smart) IFS also supports undercar skids tot. At least to the back of the seats. So the IFS cars and SXS's are missiles skidding over the tops of rocks. (designed intentionally for Skidwheeling). Definitely the fastest if you can do it, and actually fastest for winching. (No better anchor than a front SA.)

Option.: And why the game is fun. And fun is different for everyone. A $250-500K + car and a $150k+ layout for KOH week costs and then replacements are not for everyone. :beer: And just us goofs who think we can..........................:beer::beer:
 
I watched the other video a few days ago. It was awesome to get to see all the parts you have been working on for the new build and I admire the commitment you have to the project. Just the amount of time you have in to polishing all those parts is mind blowing, nevermind the fact that you made a lot of them. :smokin:
 
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SLOWPOKE693 said:
I watched the other video a few days ago. It was awesome to get to see all the parts you have been working on for the new build and I admire the commitment you have to the project. Just the amount of time you have in to polishing all those parts is mind blowing, nevermind the fact that you made a lot of them. :smokin:
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Every one of those parts had involvement by someone closer to the tech than I was. We hashed it out The parts got designed and built. In many cases the design was in cro mo and I would go from the magic points and re-design for Billet Alum. 7075. Because this is all manual machinig there is a ton of SANDING. Polishing is actually the easy part from sanding.. Some of those big parts only have 3 or 4 critical dimensions. Those are machined in first and then the rest is just whittled to a scribe line. Holding those parts gets increasingly difficult.. so do the exact first.

I couldn't figure out how to hold the uprights. So we had one printed, then I started with wood and figured out a rotating pedestal mount to simulate a 4 axis mill. and then the real deals.

The exception was putting about 100 hours into the two trailing arms and the last project was threading for the 1.5" heim joint. This was my solution.


Again. I have been stopped to figure out an alum frame. I am good enough to build one out of wood now. Time to cleanup the garage.
 
I may have missed it in the video but when did you start collecting parts and is there a year that you hope to have a running driving jeep?
 
Yeh the new "Flatty" has been going on since maybe 1999. I know I owe a buddy who said it wouldn't be done by 2000. At that time the scope was a LOT less. Think about 95" wheelbase and Model 44 aluminum centers. Alum SA/ alum IRS. It was easy charging on until Jason Scherer challenged a group of us to design a IFS. Well that ultimately created a turn for me to IFS ...AND larger tires and 115" wheelbase. Major changes and GLAD I didn't build in 2000. Just the last 5 years has created major changes for a recreational plated KOH Willy wagon/Jeepster. (You have to beat a $150K JL after all...)The longer wheelbase makes a flatty not look right. Then 39-40" tires became a thing and the IFS got a billet 9" and the rear a 12"quick change. It was only till three years ago that I decided to Freeze the build. No more new big Tech. (I lucked out on no portals or active shocks) The IFS is about 4th generation and been on the KOH podium and winning several times. The geometry is complicated but just points in the billet now. Nothing is really parallel but just points to pick up. Nope...I didn't create those points, but did have a voice is saying what we wanted the wheel to do. Most of you all have heard that. Lately I did some crap around the house and my hands went to sleep. That meant no nothing actually. I am about half way back so the juices are running again. I would like to have a chassis done for Santa next year... We will see as a one-man game. And there are almost zero offroad techies in the Bay Area. No one to bump daily stuff off of. So you have to think out everything about 3 times from 3 different angles to come up with a plan worth trying. Better than TV. But hitting a gym would be helpful for the knees. Cheers...Pressing on. I get it. It is NOT fun looking a obsolete parts representing hundreds of hours. Nor parts that are waiting to be assembled and 2025 obsolete.
 
bdkw1 said:
So does that mean the diff on a swingarm idea didn't make it?
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Not 100% positive but I don't think it was that much of an advantage for the complexity. The brothers are tough and have little mechanical compassion. The cars ARE tough and probably among the heaviest. They don't look it, but get the job done.

My back and neck can tell you that a IRS diff in the center is a definite disadvantage in the rough and fast g-outs. The new rig is IRS, but I'm not going back now. At least it is different and they do work well in the dunes.
 
Isdtbower said:
Every one of those parts had involvement by someone closer to the tech than I was. We hashed it out The parts got designed and built. In many cases the design was in cro mo and I would go from the magic points and re-design for Billet Alum. 7075. Because this is all manual machinig there is a ton of SANDING. Polishing is actually the easy part from sanding.. Some of those big parts only have 3 or 4 critical dimensions. Those are machined in first and then the rest is just whittled to a scribe line. Holding those parts gets increasingly difficult.. so do the exact first.

I couldn't figure out how to hold the uprights. So we had one printed, then I started with wood and figured out a rotating pedestal mount to simulate a 4 axis mill. and then the real deals.

The exception was putting about 100 hours into the two trailing arms and the last project was threading for the 1.5" heim joint. This was my solution.


Again. I have been stopped to figure out an alum frame. I am good enough to build one out of wood now. Time to cleanup the garage.
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I will forever love this video for the ingenuity it took to do that.
 
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