Fuck turning wrenches, I wanna go wheeling; So I sold the taco.
- Thread starter Arcticelf
- Start date
I have no idea what I am looking at in that image lol
Now, does the instant center matter that much when you can focus on other things, such as SAI, camber change, and bump steer while using stock steering rack (if that's what you keep).
You don't plan to keep stock upper mounts, right? That free's up a lot of room to play with spindle design, and pivot locations to get the IC/RC you are looking for.
Now, does the instant center matter that much when you can focus on other things, such as SAI, camber change, and bump steer while using stock steering rack (if that's what you keep).
You don't plan to keep stock upper mounts, right? That free's up a lot of room to play with spindle design, and pivot locations to get the IC/RC you are looking for.
IC drives RC, holding CG and tires constant, so it does matter.
I'm moving the UCA mount, probably to the top/outer corner of the frame rail.
I'm flattening the UCA pivot axis to remove the caster change, and will live with the camber change I get. It won't be as much as stock, but there with a 15" LCA and 10" UCA I'll still get enough.
Bump steer: I'm building a spindle so I'll put the steering pickup where I need it, and the tundra rack means that really has to be custom anyway.
I'm moving the UCA mount, probably to the top/outer corner of the frame rail.
I'm flattening the UCA pivot axis to remove the caster change, and will live with the camber change I get. It won't be as much as stock, but there with a 15" LCA and 10" UCA I'll still get enough.
Bump steer: I'm building a spindle so I'll put the steering pickup where I need it, and the tundra rack means that really has to be custom anyway.
Now with labels on things.
The frame reference points are so I can mirror this and see both sides. When I make the mirror copy those lines match up on both versions and it's properly aligned.
The spindle is shown as a circle because its the easiest way to draw the two intersection points, which is what I care about. I'll have to model up the actual spindle later.
Okay I see what's going on here. The circles for the spindle had me way the fuck confused lol. Is it not easier to just draw a line connecting the pivots? That way you can easily measure the camber change.
Then you'll want to try to get a decent SAI so you aren't getting a ton of scrub radius and extra wear on your steering. Also helps with steering centering and stability.
Luckily caster curve won't be an factor for you.
Roll center can be dealt with via a sway bar if it's way low, and if it's too high you'll get jacking in corners which can't really be dealt with, without changing geometry. Do you have a target location for the RC at ride height? Remember this location can change quite a bit with ride height.
Oh I'm not saying IC doesn't matter, I'm just saying you should definitely factor in the camber curve as somewhat of a priority. Positive camber is no bueno, so definitely factor that as a priority in the equation. Having a decent amount of negative camber at bump and droop will help handling in corners, especially if your RC ends up lower. Helps keep the outer wheel from going crazy positive camber.
Then you'll want to try to get a decent SAI so you aren't getting a ton of scrub radius and extra wear on your steering. Also helps with steering centering and stability.
Luckily caster curve won't be an factor for you.
Roll center can be dealt with via a sway bar if it's way low, and if it's too high you'll get jacking in corners which can't really be dealt with, without changing geometry. Do you have a target location for the RC at ride height? Remember this location can change quite a bit with ride height.
From the perspective of making the drafting easy, the circle method works really well. I've have to go back and measure the intersection points to compute the camber curve, for both OEM and proposed new. That's today's project.
I'm trying to keep the RC similar to OEM with a 2" lift, since I know that's a reasonable handling solution. That's why I'm focused on the IC math.
SAI I'm going to have to confirm.
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second pic looks good but needs more colors like the first.
Are you sure the J arm is going to be ridged enough not to flex front to rear?
Are you sure the J arm is going to be ridged enough not to flex front to rear?
I'm going to attach them right to the corner of the frame, one more or less where the front of the existing coil bucket attaches, and the second forward of that.
That should result in less flex than the OEM UCA attachment.
I need to do the math for how far, I'd like to get .05 degrees of camber/caster adjustment per turn on the uniball.
Lets see if the new spindle will fit in the wheel, it's going to be close for sure, and I might have to use a wheel spacer, and deal with the front track being a little wider than the back.
Going by how everyone seems to build arms the lower uniball will be mounted on the LCA, so the spindle just gets mounting tabs. the upper will mount on the spindle, and the arm gets tabs. I'm not sure there's any good reason for this though, it's tempting to build both uniballs into the arms and put the mounting tabs on the spindle.
Going by how everyone seems to build arms the lower uniball will be mounted on the LCA, so the spindle just gets mounting tabs. the upper will mount on the spindle, and the arm gets tabs. I'm not sure there's any good reason for this though, it's tempting to build both uniballs into the arms and put the mounting tabs on the spindle.
Chris In Milwaukee
Ain’t no mo’
CAD/CAM = Cardboard Aided Design/Manufacturing
Sometimes still the easiest way to prototype.
Stairgod
Two bad decisions away from buying a bulldozer
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My fave
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My cardboard always catches on fire.
You're not supposed to use a plasma cutter on it.
Spindle fits with a spacer, so it looks like I'm gaining 1.5" per side of track width, but there doesn't appear to be a good set of arm lengths that will work with a spindle which fits inside the wheel.
NICE! Have you measured your scrub radius with the spacer and that spindle?
No, that's next, although I think it will be very close to OEM+spacer.