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DIY Drop Spindle

 
Old 04-03-2018, 11:56 PM
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Default DIY Drop Spindle

I had a thought last night whilst looking at the suspension arms. Is there any reason why I can't invert the upper ball joint and mount the suspension arm underneath the spindle? I'd weld a spherical sleeve into the suspension arm and make a custom tapered spindle bolt that fixed through the spindle taper to the spherical below. I could then use some packers to change the spindle offset, or alter the roll centres.

On the bottom ball joint, I'd once again replace with a spherical with a large offset pin to the spindle or alternative weld an offset into the lower arm to lift the stock ball joint. Basically pack it up 1.5" inches or so. The steering arm would also need a large offset packer of the same size to drop it back down to it's original location.

Is there something fundamentally wrong with doing this? It's not changing any of the pivot locations, so effectively its just lifting the hub up 1.5" or so. There would be some increase moment and shear loading on the joints but that should just be a matter of sizing the extension pins and spherical appropriately. There must be some reason why this hasn't been attempted before.
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Old 04-04-2018, 06:08 AM
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Looking at the clearances, a 1/2" rod eye would bolt up nicely to the underside of the spindle with a small packer to give it some clearance. It will clear the inside edge of the spindle. I can cut the end section off the UCA and weld on reinforcing plate with a threaded tube to fit the rod end. This means it can be adjusted both for camber and roll center by packing up or down the rod eye.

The bottom ball joint is more troubling. I need to drop it downwards by 1.5" by a spacer of some sort, but the force form the cornering G's is on this joint in shear so it will need to be fairly strong. I'll have a look at the bottom of the spindle tonight and see if there is a way to make it strong enough.
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Old 04-04-2018, 02:10 PM
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I'm sure it's going to create some strange problems. Bump steer and scrub radius would be altered. I would have to look at it but I think that the spindle and brake caliper may contact the upper a arm at some point in its range of steering or vertical motion if the arm was located beneath the pivot. If not, I would say simply flip the upper a arm over to mount it from beneath.

Definitely some weird stuff and totally unnecessary when it's possible to put the frame of the car flat on the ground without doing any of this.
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Old 04-04-2018, 06:44 PM
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Both bump steer and scrub radius should be identical to an unlowered car and should be improved. The only real change is the wheel, spindle and brakes lifting in reference to the suspension arms so you'll get the similar clearance issues as with the Keisler drop spindles. As you say the flipped UCA which might get near the brake caliper.

Unlike the Keisler spindles, there will be no inbuilt change to camber so the lower ball joint will get closer to the heat shield which could be an issue.
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Old 04-04-2018, 11:01 PM
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Originally Posted by Madjak View Post
The bottom ball joint is more troubling. I need to drop it downwards by 1.5" by a spacer of some sort, but the force form the cornering G's is on this joint in shear so it will need to be fairly strong. I'll have a look at the bottom of the spindle tonight and see if there is a way to make it strong enough.
Too bad you canít fit the taller ball joints like Iíve seen on other strut based cars. I bet if there were enough demand Bauer could make a run of em.

The upper is the challenge IMHO. Itís gonna take something creative to make work.

Lastly I am not sure you want to go for a full 1.5Ē correction. I question the value of getting back to that part of the camber curve. Iíd be more tempted to split the baby and go 3/4Ē and see what happens.
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