UCA Clearance DIY
#16
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yeah... ucf20 is a slightly different animal as far as how it sits. looks lower. if you're going air then you shouldn't have a problem parking on the ground once you raise the exhaust and clearance the uca.
#19
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first of all, the 2 are a little different in what they accomplish. cutting the knuckle is a way of lowering while reducing the need for clearance. cutting the hole is just providing clearance.
now me personally, i would never cut the knuckle. the main reason being, although it can be done, i am against welding cast metal, especially in such a critical area. the other being changes to suspension geometry: upper and lower arms are made to articulate together on a certain path. changing the length of the knuckle changes the relationship of those paths. i'm not an engineer so i can't say for sure that it's a change for the worse, but for the same reason i won't mess with it.
thanks.
you're a bad mf'er if you can hammer it out. the external layer is just sheet metal but the layer beneath is structural.
now me personally, i would never cut the knuckle. the main reason being, although it can be done, i am against welding cast metal, especially in such a critical area. the other being changes to suspension geometry: upper and lower arms are made to articulate together on a certain path. changing the length of the knuckle changes the relationship of those paths. i'm not an engineer so i can't say for sure that it's a change for the worse, but for the same reason i won't mess with it.
thanks.
you're a bad mf'er if you can hammer it out. the external layer is just sheet metal but the layer beneath is structural.
I AM an engineer and i would NEVER cut the UCA. this provides a weak point in a critical area of the suspension. on the other hand, if the UCA fails you will definately have the LOWEST car on the block...it will be on the ground.
you are also correct that it would change the suspension geometry, which would also put greater stresses on the UCA.
#21
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yeah, i read it wrong. i thought they were shortening the UCA, but it was actually the knuckle arm. regardless, the repeated vibration on the cut and welded joint is a stress point. mainly because of the cast steel construction. cutting and welding the knuckle arm will give you more negative camber and will also cause the UCA and LCA geometry to be skewed.
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#23
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this is what i mean by changes in geometry. not to scale but you can see how the change in distance between the outer pivot points (bjs) effects the camber curve.
#27
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what I also saw on some japanees blog is that on the 98-00 LS400 there is not enough to cut this hole (there was cut a much bigger hole then I have or I saw here), you need to cut some metal in the inside. In my case the UCA goes against the metal inside the fender, not the UCA hole.
picture tells more then I write:
so if you want to sit LOW, you need to do much more then just a suspension change; exhaust and other things is a must.
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