front susp kickup, anti-dive?

[WillyChang]

Ok, just only this week I got around to reading the Manual... []

On a Touring Car with adjustable suspension pivot point holders,

manual says I should be running the front suspension with the

front holder jacked up 0.7mm higher than the rear holder.

Rear suspension has both holders level.

Turns out I've been running both my cars with Zero kickup.

Now re-adjusting all 3 to manual specs.

How does this kickup affect handling? [?]

[sosidge]

Assuming you adjust caster blocks to retain the same angle, front kickup will give a better ride over bumps, but a slower weight transfer to the front under braking, so you would get a slightly less responsive turn-in off-power.

Since you've been running the same caster blocks, an added effect of the increased caster with kick-up is less off-power steering, more on-power steering, more straight-line stability.

[terry.sc]

If the front suspension has a C hub suspension (upright is fastened to the wishbone) an increase in kickup will give you more caster (kingpin is angled back from vertical). More caster makes the car more stable in a straight line.For on road use the more caster angle the more stable the car is on power, and the more steering the car has off power. (For some strange reason this works in reverse for off road, presumably to do with the large movements in the chassis angle under braking and acceleration). For example if the car handles fine but could do with turning into the corner at bit harder, increase the caster angle(tilt the kingpin back). If the car handles fine but runs wide coming out of the corners under power decrease the caster angle.

If the touring car has pivot ball suspension by adding rake to the lower suspension arms it causes the kingpin to straighten up when the suspension is compressed when cornering, which means the car has plenty of caster for turning in, then the suspension compresses when cornering so giving more steering coming out of the corner. Suspension then extends to normal to give the extra caster for stability on the straights. This 'active caster' is fairly standard these days on 1/12 and 1/10 pan cars and some touring cars, such as the Xpress with its multi link front suspension.

[WillyChang]

Adds more caster, eh? Didn't think of that, yes good one!

C-hubs only, we're talking about 414/TA04 suspension on a Evo3.

Might explain why I seem to have more steering than what others are

reporting as the norm. I'll try it back at manual specs next and

see what difference 0.7mm makes (its only a tiny amt) and if

the turn-in isn't as lively as I like it, we'll revert. [8D]

All cars equipped with torque rods, so this kinda decreases the

castor a little when the suspension moves high up too.

[rc-martin]

think i might reduce the kick-up on my evo3 then, got to be worth a try, still having a lack of low speed cornering performance.

[WillyChang]

Worth a shot! Those silly little 0.7mm washers are so easy to lose,

and worse moreover, local Tamiya importer DON'T carry spares. [:I]

Mine's setup with stock manual settings, apart from:

-60wt oil (3 hole piston) in front, 40wt rear

-same springs all round (yellow), sometimes blue in front

-no kickup at front, that was news to me

-torque rods

-A/A blocks at rear with the std 2deg blocks (total rear toein 2deg)

Its quite lively and has enough steering for my tastes, but it

does scrub off some speed thru the corners. I'm gonna go do more

experimenting to make it keep its corner speed up all the way.

[WillyChang]

Back from the track.

Ok, after adding the 0.7mm kickup...

1) doesn't seem to have affected turn-in much, if at all

2) mid-corner snap might be a little less sharp, but is much more

controllable now rather than before. Perfect drift is easier now.

3) corner exit still seems the same, no change

4) tracking on straight seems a bit better

Added the kickup washers to both cars, an EvoIII running 540

and the EvoIIISL with Novak SS.

The 540 car is now so nicely dialled, it was running around

the whole track without even needing to liftoff anymore. []