Quote:
Originally Posted by black95maro
bigger tb=more air=more power
 |
Right. However, on a TPI car, a bigger TB is not gonna give you more hp, especially on a stock motor. The stock throttlebody size can support 300hp. Even the 330hp LT4 used a stock 48mm throttlebody. Once you dig into the motor and REQUIRE more airflow (better flowing heads, more agressive cam) then the bigger throttlebody is a worthwhile investment. A heads/cam car would see a nice improvement with a 52mm TB; I put one on my car and the butt-o-meter says my ZZ4-cammed 355 needed it. A 58mm is pure overkill, unless you've got forced induction or a ridiculous cam and head combo.
The SLP runners work on the same principle. Better airflow = more power. The tubes are bigger diameter than stock, and are also siamesed at the top of the runners to aid in flow.