,
The rear lower control arm rear bushing is to be replaced by this Whiteline urethane part that has thick metal reinforced flanges that act like thrust bearings, limiting for and aft movement generated by braking but allowing the arm to articulate freely.
Howard Watanabe of Technosquare uses a pneumatic hammer to break the ball joint loose. The factory ball joints were very tight and hard to remove and it took a bunch of penetrating oil, prying, and hammering to break the ball joint loose. BTW, we used Mobil 1 penetrating oil and we think this is our new favorite. It seems to work better than our old favorite Aerokroil. It really gets in there. As soon as we sprayed the ball joint it popped right off and the oil was through the taper. In fact it got most of the really tight stuff on this car off right away.
Howard presses out the ball joint.
Howard presses out the front lower control arm bushing.
The steering rack bushings are pressed out next.
The Whiteline front bushing compared to stock when viewed from above. The stock rubber bushing has huge windows cut out for flex and the material itself is pretty soft. This probably allows for up to half an inch of movement in the wrong directions. The Whiteline part has just enough flex so as not to bind, the rest is solid urethane.
2 comments
Mike,
Appreciate all your suspension articles on motoiq.
If I understand correctly the stock alignment spec is:
Camber: 0, Caster: 5°54′, Steering Axis Inclination: 15°31′ , Toe: 0mm
and the modified is:
Camber: 3.5 deg neg, Caster: 8°, Steering Axis Inclination: 11° , Toe: 3mm toe out
The camber, castor and toe all seem pretty conventional (and good) mods for getting good turn in, good mid corner front end grip and a car that is responsive to the wheel without getting to spookiness and instability. I am intrigued, and have to admit my ability to think about the geometry without a model is at its limit.
Is the effort of reducing the steering axis inclination about minimising scrub radius? Or is it something more.
In short, could you explain a little more what your aims and ideas are around “We prefer to run minimal scrub and lead the caster with king pin angle by a few degrees.”?
Tuning JDM and British cars I never found an extra degree of castor I didn’t like, but can admit to never being up for exploring KPI. Though with an adjustable strut top and camber pins on a mcpherson strut its very very doable.
Thanks!
David
Actually reducing KPI increases scrub but it also makes for more wheel tilt in the wrong direction that is countered by the caster.