Originally Posted by DallasBoosted
I think if you used lighter seats (pole positions maybe?) and got aftermarket brakes F/R to save weight (turns out aluminum is lighter than iron) you could get ~400lbs out.
This would get you down around 3100lbs. Is it worth it? Here's an answer: "It depends." What do you use it for? Are you going to care if you're 1-2 seconds faster per lap at your track day? Does maximizing every little bit of the car seem fun to you? If not, then no. It's not worth it. It's a fair amount of money for ~10% weight and you probably won't notice it much on the street. For general street driving it is much easier (and cheaper) to add power.
I think you may be underestimating the lap time reduction. 400 lbs less means you can carry much more speed into the bends. which in turn means you will be much faster in the straights as your exit speed will be significantly higher. Easily 5 seconds per lap on a 2:00 lap?
But agreed that for street it makes no sense!