Two steps forward, one step back

I spent a few hours dialing in the Hyper TT (again!).  This is the most challenging car I've had to setup so far.  It's definitely been fun, but it seems like every time I work on the car, I find some new problem to solve.

The new diffs definitely made a HUGE difference in driving.  Before, the car was diff'ing out all over the place, and very inconsistent on power delivery, and handling.  With the 5k/7k/3k (front/center/rear) combo, it's tracking quite nicely.  It'll pull a small wheelie down the front straight, but the center diff is still bleeding power front to rear under acceleration and braking, which makes the truck more controllable.  I'll probably leave it as such for a while, this seems like a good starting point.

I also tested a heavier front shock weight oil which worked better -- 30wt. was too light, I bumped it up to 32.5wt Associated oil and that's better.

Finally I tested lowering the ride height, but at least with this shock package, there is too much chassis slap off the face of the jump and landing.  I tried 26mm front and rear, but it was not working as well, so I'm back to 28mm.  That seems to work better.  With the heavy weight of the truck, you'd have to use pretty heavy shock oil and springs if you want to lower it.  I'm already at the stiffest springs I can find that fit the shocks.

So I feel I made progress, but I ran into an issue where shock compression was causing me to lose steering travel.  At full lock, I have pretty good turn-in, but as the shock compresses, the steering knuckles were forced inward (negative bumpsteer), which was straining my servo.  You can see in this video, that when I compress the suspension, the servo is forced back a bit.

I think it's a combination of the steering links and the Integy steering knuckles.  The knuckles don't have as much articulation as the stock knuckles, so I ended up grinding them down a bit to get more articulation.  It's still not perfect, but it's better.

The steering knuckles have a square cutout where the pillowball goes through, but the original knuckles are beveled so they have more articulation.  You can see where the pillowballs are already rubbing on the sides of the window, so I ground them down a bit more.

That helps quite a bit, make sure you look into it if you pick up these knuckles.