I used to be Service Advisor with LTM.
For CT9A Evo VIII & IX, HKS GT 2835 Turbo Kit is very
popular for horsepower gains. 450 -480 HP depending on boost
setting. For boost controller, HKS EVC, Apexi AVCR & Blitz SBC
are the common choices. Exhaust systems, endless brands to choose
from although Fujitsubo may be more popular, Handling, you may want
Tein Superstreet Coilover Kits & Cusco Strut Bars.
For CZ4A Evo X, parts are rather limited. Turbo Kit not
available yet. Only Exhaust, Suspension & Boost Controller.
Because Evo X runs on E-throttle, you can also install throttle
controller. Available from Blitz & Pivot.
on my VIII: Aquamist 2D/DDS3 injecting water, Autronic ecu,
272I/264E cams, Greddy Ti catback + cat delete/helix dp...apexi
avcr
my IX:Aquamist HFS-1, switching it out to Aquamist HFS-6 in a
several weeks, hallman mbc, greddy ti catback + cat delete/forgot
where i got the dp from. Zeitronix wideband/map sensor