Saw a few posts on queries regarding this topic. Thought i compile and put one together. This is a compilation and not exactly from personal experience. So you may need to take it with a pinch of salt and trial and error for yourself to see what suits you.
Mitsubishi Lancer Evolution III GSR (CE9A)Specifications
engine: 1997cc 4-cyl in-line DOHC 16-valve intercooler turbo (4G63)
transmission: 5-speed manual
drivetrain: full-time 4WD
max power: 270 bhp at 6000 RPM
max torque: 228 ft lbs at 3000 rpm
weight: 1260 kg (or 2778 lbs)
Summary of tunes
N tune - like A tune only do not have the sticker
A tune - the fastest, but can be said drifty, the misfiring system (bang bang rules), used by Kyouichi in Initial D, one of the most stock looking A tune car
B tune - grip and handling
C tune - more to speed and acceleration because of carbon fibre parts
Engine/internals
A tune - from about 310PS to 350PS, have misfiring system
B tune - useless without misfiring
C tune - useless without misfiring
Wheels
A tune - Mitsubishi (Enkei) - very drifty, bad in wet
B tune - Enkei white 5-spoke
C tune - Enkei grey multi-spoke
no tune - RS Watanabe black 8-spoke - drifty but still controllable
no tune - RS Watanabe gold 8-spoke - good grip on dry but bad in rain
Muffler
A tune - Initial D Kyouichi/Kyle type muffler - HP and acceleration - all tracks
B tune - Fujitsubo - average, nothing special - all tracks
C tune - Creative Sports straight flow exhaust - 3rd and 4th gear more powerful than A tune, other gears weaker - Akina, Happo, Iro
Rear spoiler/wing
A tune - Mitsubishi - drifty
B tune - HKS GT wing - stability, wide turning radius, good for high speed corners
C tune - Creative Sports partial carbon fibre wing - lightweight but stable, good for low speed corners
Front bumper
A tune - Mitsubishi
B tune - HKS - handling
C tune - Mitsubishi
Side window mirrors
A tune - Mitsubishi
B tune - Mitsubishi
C tune - Creative Sports aero mirror - lightweight
Stickers
A tune - Initial D Emperor sticker - slight increase in accel
none for other tunes
Mitsubishi Lancer Evolution IV RS (CN9A)Lancer Evolution IV RS Specifications...
Engine: 4-cyl in-line DOHC 16-valve intercooled turbocharged 2.0 liter
Transmission: 5-speed manual
Trivetrain: Full-Time 4WD
Max power: 280 hp at 6500 rpm
Max torque: 260 lb-ft torque at 3000 rpm
weight: 2976 lb (1350 kg)
Summary of tunes
N tune - best in everything but may drift a bit
A tune - best accel
B tune - best speed
C tune - cornering
D tune - stable
Engine/internals
A tune - should have 300PS
Other tunes unknown
Wheels
A tune - stock - average grip, average in rain, average start - all course
B tune - Enkei white 5-spoke - excellent grip, average in rain, good start
C tune - Enkei grey multispoke - good grip, good in rain, good start
D tune - Valdi Sport gold 6-spoke - avg grip, excellent in rain, bad start
no tune - Enkei white 6-spoke - excellent grip, good in rain, excellent start - all courses
Muffler
N tune - Mitsubishi single - avg accel, bad steer, good start, 1-2 good 3-5 avg - all courses
A tune - Initial D Hawk/Seiji type single pipe muffler - avg accel, avg steer, excellent start, 1-3 excellent 4 avg 5 bad - last 3 courses
B tune - HKS - good accel, good steer, good start, 1-4 good 5 avg - all courses
C tune - Fujitsubo - good accel, excellent steer, avg start, 1-3 avg 4 bad 5 good - first 3 courses
D tune - Bozz Speed dual muffler - excellent accel, excellent steer, good start, 1-3 good 4 excellent 5 avg - last 3 courses
Rear spoiler/wing
N tune - Mitsubishi - avg accel, avg steer, good in rain
A tune - Initial D lightened Evo IV spoiler - good accel, good steer, avg in rain
B tune - HKS GT wing - excellent accel, excellent steer, bad in rain, unstable at high speed, AVOID RAIN, great steering
C tune - Valdi Sport Evo V-type spoiler - good accel, good steer, excellent in rain, great in the rain, stable at high speed, good steering
D tune - Bozz Speed - excellent accel, good steer, avg in rain, not as light as B. very stable at high speed, OK in the rain
Front bumper
N tune - Mitsubishi - good accel, avg steer, stable
A tune - Mitsubishi - same as N
B tune - HKS - excellent accel, excellent steer, very unstable, super lightweight, get's "odd" at high speed, crap in rain
C tune - Valdi Sport - excellent accel, good steer, unstable, lightweight, sometimes gets strange at high speed, OK for rain
D tune - Bozz Speed (Evo IV bumper + additional spoiler lip) - avg accel, good steer, very stable, Great at high speed due to the extra down force, great in rain
Stickers
A tune - Monster Sport sticker - +1.5% accel
A tune - Initial D Emperor sticker - +1.5% accel
all of the information are from RedLine12k
Mitsubishi Lancer Evolution VII GSR (CT9A)Specification
engine: 1997cc 4-cyl in-line DOHC 16-valve intercooler turbo
transmission: 5-speed manual
drivetrain: full-time 4WD
max power: 280 PS at 6500 RPM
max torque: 282.5 ft/lbs at 3500 RPM
weight: 1400 kg (or 3086 lbs)
Summary of tunes
A tune - grip, but perhaps handling better than B tune
B tune - grip, much faster than A tune
C tune - accel and speed with tons of carbon fibre parts, but handling may be crazy
Engine/internals
N tune - unknown
A tune - unknown
B tune - unknown
C tune - unknown
Wheels
N tune - Mitsubishi - average, fairly well in dry or rain
A tune - Ralliart grey multispoke
B tune - Enkei white 5-spoke - have grip in both dry and wet
C tune - Monster Sport gold 6-spoke - fast but handles bad
no tune - Volk Racing - enough said. sucks in handling but fast
no tune - Enkei multispoke - drifty
Muffler
N tune - Mitsubishi - fast launch and accel, average on upper gears
A tune - Ralliart - normal start and accel, weaker 3rd and 4th gear, 5th better than Mitsubishi
B tune - Creative Sports
C tune - Monster Sport - OK start, 3rd to 5th gear very powerful
Rear spoiler/wing
N tune - Mitsubishi - average on dry and rain
A tune - Valdi Sport GT wing
B tune - Creative Sports GT wing
C tune - Monster Sport Evo VII spoiler with carbon fibre spoiler - lightweight
Front bumper
N tune - Mitsubishi
A tune - Valdi Sport
B tune - Creative Sports
C tune - Monster Sport (Evo VII bumper + carbon fibre spoiler lip)
Rear bumper
N tune - Mitsubishi
A tune - Mitsubishi
B tune - Mitsubishi
C tune - Monster Sport carbon trunk - lightweight
Hood
N tune - Mitsubishi
A tune - Valdi Sport that looks like Evo VIII's hood
B tune - Creative Sports GT-type hood
C tune - Monster Sport carbon fibre hood - lightweight
Hope this has helped.
