Renntech (and advertiser here on the forum and in the shop) I believe offers one of their upgrade packages as a "Z Killer". But it's on the order of 15 times what you're looking to invest. $1k won't beat a Z straight up. $500 for an Upsolute ECU upgrade and K&N air filters will get you much closer than $500 spent anywhere else, and will leave you $500 for gas to practice launch and driving techniques so the next time you're at a light next to some a-hole in a Z, you'll SMOKE 'em off the line, and that's where racing is won and lost anyway.