Outer Limits 4x4 Board

I want to confirm caster angle on the Kingpin for the Winch truck I am building.
I am working with a Currie Iron Jock utilizing F350 style knuckles, the caster angle I would like some input as I am guessing with higher speed style events it is more important than in Crawling stye wheeling. With the housing being hi-pinion I just want to see if correct caster on the knuckles is going to have pinion where I want it pointing at Xfer or whether I have to compromise a little as room under the Lux is VERY tight.


brooksy

You need one of these tools
http://www.speedwaymotors.com/Deco-Magn ... ,2698.html" onclick="window.open(this.href);return false;

You will be able to check it your self all the time then but you do want the caster to be correct other wise wheel shimmy can be a problem

I havent done any racing, but when I did a knuckle rotation on my 80series, I set caster at 4degrees (factory spec is 2degrees +/- 1 degree)
With 4" lift and 35" muddies, steering was firm and direct at any speeds on the highway, it didn't tramtrack in ruts etc, was stable under brakes on broken surfaces etc.
After driving the car as purchased with lift and negative caster which was dead set scary, i wanted to be sure i had faster angles at the upper limit of factory specs or higher.
I would definitely do the same again.

Brooksy, what size tyres are you going to run? (36-37??) what is stock castor on the hi lux? Rangies etc have 3 degrees but this may be different to a 2wd truck? I have read guys running more than stock on lifted trucks with bigger tyres...

edit: the above reply, posted as I was typing, confirms what I was thinking.... just a punt though

Hay brooksy i ask around alot of people in the (Know) before welding my diff together and most people said 7 degs was the go for abit of speed so thats what i went for and it looks pretty good to me

The more castor the better the high speed stabilty generally.
From memory superior recommends less castor for big tyres when correctting castor, on a 5 inch lift on 37s you would only correct by 4 degrees not 5 degrees.
Also watch that as you rotate the knuckles you can end up with positive camber.

I go 6 in all my projects. it gives me the chance to lift the ride height and lose a degree or two and still be ok.

As Turbo GU said. I'm sure it is from stock. 1 deg of castor for every inch over the first inch of lift.

Willy Hilux wrote:As Turbo GU said. I'm sure it is from stock. 1 deg of castor for every inch over the first inch of lift.

That's a generalisation, it will change by different amounts with different length radius arms etc.
In an 80series for example 1" lift changes caster by approx 1.7degrees

I have 8 degrees built into my RockJock.

Jason

Thanks for the input guys. It looks like I will be aiming at about 6* on the knuckles.
Everything seems to line up OK, just need to talk Mick into going Superflex arms instead of 5 link



brooksy