That looks very good! I have a very similar set up on my YJ . Works sweet. When I upgraded from a D30 to D44s I had problems with my brake calipers hitting. I had to adjust the steer stops to cure it If I had tested it with the brakes on I would have moved my mounts in a little and I would have been able to turn sharper. it was never a problem on the D30 due to smaller calipers and rotors Just a thought. Nice Build!! Keep up the good work!
Great fabrication you are doing there. Looks clean and methodical.
I have gone through several iterations of different suspensions on the front of my jeep and would like to note some of my observations. First I ran extended ford C clamp radius arms with RE joints on the frame side, next was a radius arm similar to what you are building now, after that was the same setup with only one top link, and lastly is a 3 link(same lowers with the addition of a separate upper).
The ford radius arms and fabricated radius arms with both uppers have a lot of bind during articulation. When one arm goes up or down in relation to the other they actually need to allow the axle to twist. The easiest way to illustrate this is to hold a pencil out in front of you with both hands, pinched between your pointer and middle fingers to simulate the radius arms. If you move the pencil through articulation you will feel this twist.
The easy way to get around this binding problem is to remove one upper. Presto, no more binding. This is what the ford guys(mostly early bronco) refer to as a ‘wristed’ radius arm setup, because one side is allowed to move as needed.
Speaking to the overall design of front suspensions, there is one calculated value that I have become concerned with more than others and that is the % of Anti Dive (AD). Loosely defined, this is the percentage of the load exerted on the suspension that is transferred through the links rather than through the springs during braking. 100% AD is the point where all of the suspension load is transferred through the links with no load on the springs. AD less than 100% will have the noticeable condition of ‘brake dive’, where the nose of the vehicle dives during hard braking.
AD has the opposite effect during acceleration(while the tire has traction). AD over 100% in acceleration will cause the links to try and compress the springs. This compression happens until the tire breaks traction and the suspension will reset. This oscillation can be nasty under various conditions, but it is difficult to see unless the vehicle is geared fairly low.
If your radius arms are fairly parallel to horizontal the AD will be low. As angle gets steeper down from the frame to the axle AD will go up. The difficulty I have noticed with a radius arm setup vs. the 3 link is that the AD starts as a higher % and changes so much dynamically.
For example, if you are going up a steep incline it is natural for the front suspension to unload. This causes the AD to go up with either suspension type. With the radius arms that is around 100 it can go up to 160 for example, where the 3 link may go from 70 to 100. With the radius arm setup, as the AD goes way up past 100% and the front tires maintain traction the suspension will try to compress the springs and traction will be broken. This effect is much less noticeable with the 3link, especially if the AD starts low enough that it will not go over 100% during normally encountered conditions.
In summary, I would council you to consider running a single upper 3rd link. I would mount the frame side to your crossmember above the lower mounts. It would be good to have a couple of vertical adjustments there from 75-100% of the vertical distance of the axle side separation. The only drawback I have seen from my arrangement similar to this is more brake dive. If that is a concern you would have to build in less vertical separation at the frame side to get your static AD higher. Either way, the dynamic changes to AD will be much less by decoupling the upper link from the lower.
If you do stay with the radius arm design I strongly advise you to not run two upper links on your radius arms as shown. If there is not enough deflection in the joints to allow for the axle to twist you could damage the axle or your brackets.
If anyone has any questions, or if I screwed anything up, please let me know. This is all just from my research and personal experience on my rig. The great thing about fabricating your own parts is of course that each person is free to design to whichever requirements they think are most important.
ExCabSwap: The wind there looks horrible... Still worth it haha
Feb 1, 2016 18:43:45 GMT -8
ExCabSwap: Finishing up the fuel tank... Hope to see you all Tuesday in my extended cab!
Feb 6, 2016 1:43:36 GMT -8
poorboy: Can somebody give me the official rules for the Cowbell please?
May 8, 2016 15:26:47 GMT -8
Wyldman: The Cowbell... If you are a club member and you're on one of our wheelin' trips. If you get stuck on an obstacle and have to be pulled out by your winch or someone elses winch/strap. You earn the Cowbell.
May 9, 2016 15:46:03 GMT -8
poorboy: Wyldman, I got to see the passing of the bell at the meeting and learned quite a bit about the tradition.
May 11, 2016 13:03:11 GMT -8
ljdude: Who has the cowbell?
Jul 20, 2016 23:45:14 GMT -8
petee: who has the cowbell
Aug 7, 2016 20:00:28 GMT -8