throttle body spacer

Hi, I've been back tracking through my page and remember thinking about getting a 'Throttle-Body Spacer'... I have an R33 GTS 2L Non Turbo My question is :- What is a throttle-body spacer, what does it do, is it a good/bad idea & how much are they ?? Hope someone can help as I seem to have...

[/IMG] Hi, I know my engine is bottom of the Skyline chain, (RB20E - 2L GTS AUTO NON TURBO) But until I can afford my GTS-T engine upgrade, I want to get her at least sounding a bit nicer and performing a bit better too if possible. I plan to take off the stock air-filter and housing and...