S13 Redtop - T25 turbo, pentroof cylinder head design, ~205hp
S13 Blacktop - T25 Turbo, flathead cylinder head, ~205hp
S14 Blacktop - T28 Turbo, VTC, flathead cylinder head design, ~220hp
S15 Blacktop - T28 Turbo with some mods, VTC, flathead cylinder head design. ~250hp
the VTC really doesnt add more power to the engine, just a little bit. the differences in power are actually from the bigger turbo designs. pentroof heads are obviously some of the best designs, specially cuz it can be compared to a HEMI and equip 4 valves per cylinder without a radical design. they are all 2.0L (duhh), and all the sylvia sr20's are turbo equipped (sr20det). all are aluminum block and heads, and only the S15 model requires the 6-speed transmission. the rest use the same 5 speed transmission found in teh RB20DET packing R32 Skyline GTS-T, and the american versions of the sylvias (240sx and 200sx)
Supra: To surpass or go beyond.