ainwarhol

I just bought a 2002 IS300 that came with the gear below from the previous owner, and it's got wicked bump steer at mid- to high-speeds:

19x9 generic wheels
215/35R19 Nittos
Megan Racing rear lower control arms
Tokico "famous blue" shocks
Tein S.Tech lowering springs

I hate the wheels and the ride. It's too stiff and uncomfortable and it's got wicked bump steer issues. I've had it recently aligned which hasn't solved the issue.

In October I'm planning on getting new 18x8" wheels with 225/40 tires as well as a full air-ride setup (hybrid of UAS bags and Accuair gear/mgmt).

I suspect these upgrades will improve the quality of the ride, but will it also solve my bump steer issues?

Or while I'm installing the air kit, are there other things I should be looking to replace to help out? (bushings, arms, rods, etc)

bazzle01

You will need to bring height back to near OE ride height plus have tyres that are made for the rim size.
Also check front lower control arm inner rear bushes.