SPC UCA owners... GET IN HERE!!! (caster settings)

[pfran42]

I'm planning on installing some SPC UCAs tomorrow and was interested in gathering data from people who are running them.

My relevant build specs:

- 2.5" front lift
- Slee Diff Drop
- 295/70/r18
- 1 1/4" wheel spacers

So what position did you end up setting your caster star plates to?

Maybe we can help out future SPC UCA owners by listing the following:

- Front lift height
- Diff drop (yes/no)
- Tire size
- Wheel spacers (yes/no) - if yes, (width)
- Caster star plate settings (A, B, C,...)
- Any other useful data?

 

[jgray]

Position D! Even added some custom stickers. 2.75" front lift - 3" in the back. Diff drop.. Was wondering if you sold off the 100 Paul! The SPC's are a nice upgrade!

 

[Kofoed]

They say to start with factory cams at zero, and spc plate in D positon, then align. Major adjustments with spc plate, minor with cams. But you probably already know that.

I will be doing same thing tomorrow, just reading up beforehand. Turned some spacers for the spare tire winch mod, that happens tomorrow too

 

[pfran42]

Position D! Even added some custom stickers. 2.75" front lift - 3" in the back. Diff drop.. Was wondering if you sold off the 100 Paul! The SPC's are a nice upgrade!

View attachment 1041557

Whaddup J!! I don't think I'll ever get rid of the Hundy...

I was under the impression that the increased (towards negative) caster angle on lifted 100s severely affected handling characteristics. Mine currently has aftermarket UCAs but it suffers from torque steer and twitchy handling at highway speeds. I also thought the adjustment range built in to the SPC UCAs would mitigate the steeper caster angle. If so, I wonder why running them in their "neutral" setting is working for people. I would have figured the optimal setup would be toward more (positive) caster - So something like position B or C.

 

[pfran42]

Just an update on my previous post:

I just watched the installation video on SPC-TV.com and it stated that in the Neutral (D) position, the JPC UCA has a built-in 2 degrees of positive caster. That little nugget of info explains everything...

 

[Slickspawn]

pfran I believe their neutral "D" setting is NET +1 degree positive cater. To imitate the stock caster with a lift you'd use the 'E' setting.

EDITED to correct camber to caster for the "D" setting above per @Kofoed note below (thank you). I was typing faster than I was thinking.

 

[Kofoed]

The D is total 1 degrees caster, not camber, with a 2-3 inch lift. Maybe youu had a typo

Factory caster is 3 degrees

 

[pfran42]

OK, I've got the UCAs on and I have them set to position "D" for caster. Now I just need to figure out the default setting for camber on a 2.5-3" lift? Should I just slide it roughly to the middle?

 

[Kofoed]

Factory camber is zero, disc brake shoyld be vertical with weight on. I placed a angle finder to get vert. Put 32 mm nut in center, that will be damn close, certainly to drive to alignment shop

 

[pfran42]

Done... Steering feels way more predictable. That said, I need to get an alignment ASAP.

So in all my reading, I see that most people are using the "D" setting. Any reason for not choosing "E" (as Slickspawn posted) and getting it back to factory spec?

 

[pfran42]

The D is total 1 degrees caster, not camber, with a 2-3 inch lift. Maybe youu had a typo

Factory caster is 3 degrees

Sorry, just saw this. So I should be using the "A" setting for my 2-3" lift? I still would like to hear the reasoning for why so many have chosen "D" with their 2-3" lifts.

 

[Kofoed]

I *think* the spc adds one degree caster for their arm/ball joint combo, over the three degrees built into the frame uca mount, with the cams at zero adjustment, to account for the lift. I'm parking it until i get tires next week.....then it will go up on the alignment rack.

 

[MScruiser]

Paul, you need to see my 200 next time I am in Marietta. I'll be there in a few weeks.

Also, on my 2" lift, I used the "D" setting.

 

[pfran42]

Andrew! How's the preggo wife doing? I saw some pics of the 200 on FB but I'd love to check it out. Steen (veteran on this forum) has a pretty tricked out 200 as well.

To update the thread, I eyeballed everything alignment-wise and took it in to get a "temporary" alignment. I must be a Cruiser Jedi, b/c they couldn't find anything out of spec on the front end.

To anyone who has a 2.5-3" front lift, large tires and is on the fence about SPC UCA's.... They're a game changer.

 

[MScruiser]

She's preggo alright. Yikes! I am trying to lay low right now. Only 2 more months....

We will be in town the weekend of the 20th. If you wanna meet-up, just send me a PM.

Also, my FIL mentioned wanted to do some offroading (he's got a lifted Cherokee and I've of course got my 200). Anywhere not too far from Marietta (<1.5 hours) we could have some fun at, but not get ourselves in too much trouble?

 

[Slickspawn]

@pfran42 what is the center hub to fender lip measurement on your rig?

Also I should have clarified...I can never articulate properly on an internet board! IF you kept the "E" setting, then lifted your rig, that would be what you'd see from the stock arms. So "D" is your 'best bet' as a starting point with anything 21.5" and over on the center hub to lip measurement.

 

[pfran42]

@pfran42 what is the center hub to fender lip measurement on your rig?

Also I should have clarified...I can never articulate properly on an internet board! IF you kept the "E" setting, then lifted your rig, that would be what you'd see from the stock arms. So "D" is your 'best bet' as a starting point with anything 21.5" and over on the center hub to lip measurement.

Hang on... I'll go out and get a measurement.

 

[coldwiz]

This is great pfran! My SPC's are supposed to show up tomorrow.

 

[pfran42]

I'm sitting at 22" up front and 23.5" in the back. Does this mean I can go back up a bit (.5") in the front? Now that I think about it, I lowered the front a little after being frustrated with the ride with the old setup.

Btw, what's stock center hub to fender specs again?

 

[BamaHeel]

So with a Slee diff drop and SPC's UCA there is a higher front end measurement?

As long as you're measuring what droop do you have at 22"?

Or by now at 22.5"?