if youre looking for major gains your options are limited to: either getting a boosted engine in there (stupid), topswaping (can be done fairly cheap if you have access to parts and such) or turbo (best bang for the buck but still pricey). that said, no matter how much you do to a N/A 3800, its still gonna be slow. People putting 2k into n/a mods and still be slower than a GTP with a tune....