Optimal Alignment for High Speed Running

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JCSRaptor

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2019 SC running Geiser Progressive Front Coils that increase front end height ~ 2” and levels the truck with respect to the rear suspension fitted with +2 Deavers (+2 Deavers do not lift the rear, they replace oem leafs with vastly superior ride quality but match OEM ride height in back) So both front and rear of truck are 42” high measured from floor through center line of wheel to highest point in the fender flare. Running 35” tires and have noticed a lot of shimmy above 100mph, very unnerving. Alignment toe not a concern. Looking to get an understanding for camber and caster are you guys dialing in to give optimal steering control at high speed. Truck is good up to 100 but over 100 I get shimmy. No vibration and steering is straight until the shimmy comes, feels like slipping on ice. All comments welcomed.
 

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Nex

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You go HOW fast through the Starbucks drive thru?!?

What steering wheel setting and shock setting are you using? In soft sand or wet beach? 4x4 or 4x2?

I don't have that much open sand around me so I can't give you a solid answer to your question. But wanted to ask the above questions.
 

Pacific Wheel

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As you raise the front end you typically lose some caster. Do you have adjustable uppers? If so dialing some extra caster can help with steering feel (heavier and track better). If you don't have adjustable uppers you can still dial in some caster but it is more difficult. You might be able to get some aftermarket cam bolts to help but only so much. I see most guys like 5-6 degrees positive for ideal steering feel. I think mines around 5 degrees but I'm also not going 100mph offroad (or on road lol)
 
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JCSRaptor

JCSRaptor

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Yes I have adjustable UCAs. still seeking a solution - getting closer… I think I have discovered something that explains at least some of the shimmy. When I added the Geiser springs up front w/o adjusting the camber, I effectively reduced the amount of camber. (Please correct me if this is not the case). I then purchased the adjustable camber bolt kits and have dialed in the camber back to -1.5deg with the lift. This now has the truck running tight no shimmy up to 110mph. I run my truck in safe places, no need to freak out. But , the shimmy does seems to come back pretty consistently between 108-110.

The above results all with 4.5 deg caster. I will adjust UCA to increase caster to 5-6deg to see if this will help.
 
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