lowering your car with the right springs as in not being soft springs will improve your 1/4 mile time. lowering your car improves the weight transfer with less body roll etc. also i saw a video with a 12 gt on eibach spring/stuts and sway bars improve 0-60 by .12 What i mean by the right springs(aka spring rates) is for example bc coilovers are good for the street but when it comes to racing or taking corners they are not stiff enough. Eibach springs are very good for lowering springs and good for track also. If you want just purely springs for 1/4 mile times then some good options are KWV 3's but they are expensive around $2500 and are soft enough for the street actually. QA1's are good too but I have only seen them for the fronts only on a 2011+. Tein makes really good coilovers but are a little too stiff for the street. Budget wise you could get Koni shocks and pair with Eibach springs and be just as good as the full coilover systems. Tire wise either Nitto NT555 or NT05 I prefer NT05 they seem sticker in corners and straights to me compared to nt555.
AirRaid CAI, BBK Ceramic LT Headers, BBK Catted X Pipe, Borla ATAK, MPT 93/97 Tune, Steeda LCA's and UCA, Steeda Relocation Brackets, 373 gears, WaveTrac LSD, Dynotech Driveshaft. Prothane Motor Mounts, Whiteline adjustable panhard bar & brace.Ground Control Coilovers with Koni's custom valved. Coming soon Circle D 3800 Stall and Lone Wolf Intake Manifold.