Rifled Throttle Body Spacers?

Does something like this actually work on a N/A engine, or is just like the "Tornado" crap you see on tv? I understand that a "swirling vortex of air" is faster flowing...but it has to still go through the plenum and runners before it gets where it needs to be...and by then how can it still be swirling and shit?


http://cgi.ebay.com/ebaymotors/OBX-Throttle-Body-Spacer-92-96-Honda-Prelude-Si-S-VTEC_W0QQcmdZViewItemQQcategoryZ33558QQitemZ800070 3615QQrdZ1

I happen to have a throttle body spacer on my car. What it basically does is lengthen your intake runners. No significant gains from what I can tell.

Prelude engines are designed well enough from the factory - a throttle body mod won't produce much gains unless you've done some other engine work like higher compressions pistons and a race cam.