Just for laughs, I re-opened my custom software in which I had already modeled my 2004 SSR with its new 4.56 gearing, and applied a 1000 lb weight reduction.
The effects on acceleration were as follows:
0-60 mph time: - 1.2 sec
Quarter mile time: - 1.1 sec
Quarter mile terminal speed: + 7 mph
With the 4.56 gearing, a 6200 rpm redline, 230 lb driver, 14 gallons of fuel, and 1000 lb weight reduction, this meant final numbers of:
0 to 60: 5.48 sec
Quarter mile: 14.19 sec at 99 mph
This is with the 300 hp LM4 engine, NOT the newer LS2 390 hp engine.
This is before any engine mods (like a supercharger or turbo).
See what a 1000 lb weight reduction can do?
Jim G