Initial D Takumi's 4AGE engines (150 and 240 hp)
= Bunta Tuned =
This is the stock engine equipped by the "hachi-roku", a Toyota AE86 Sprinter (1983 Corolla) Trueno (hatchback) GT-Apex, slightly tuned by Bunta Fujiwara (the father of Takumi, the main character); there are very few informations about the differences between the stock and the tuned one, we only knows that the tuned one has roughly around 150 hp, sport final muffler and rally-style gearbox.
-model: 1983 4AGE Blacktop
-displacement: 1587cc
-valvetrain: DOHC 16v
-power: N/A, but roughly around 150 hp
-torque: N/A (stock 16v 4AGE is about 140 Nm)
-rev limit: 8000 rpm
-intake: two 2-barrel carbs with two dual-flange oval air filters
-exhaust: stock exhaust manifold, no kat, stock middle muffler + sport final muffler
= Project D =
This is a regular 4AGE, heavily modified by TRD (Toyota Racing Developement) for the Formula Atlantic championship. The main differences are the dry sump lubricating system (that obviously I was not able to recreate in the game), Zetec exhaust manifold (same as before, so I used the most similar one), efi instead of carbs, VVT (but not VVL) and a much higher rev limit. In the anime/manga is implied that this engine is furthermore tuned by Bunta and the Project D staff, reaching roughly 240 hp.
-model: 1995 4AGE Silvertop
-displacement: 1587cc
-valvetrain: DOHC 20v
-power: N/A, but roughly around 240 hp
-torque: N/A (stock 20v 4AGE is around 160 Nm)
-rev limit: 11000 rpm
-intake: Multi-Point EFI, itbs with graves stacks
-exhaust: Zetec exhaust manifold, no kat, straight middle muffler + sport final muffler