chpmnsws6

iTrader: (70)

All speaking with a stock bottom end I'm trying to keep alive. I have an early LS2 with a D1SC on an otherwise untouched engine (besides Bolton's of course). Rather then putting a camshaft in to increase airflow, why can't one just pulley down? Is it sound only or is there more merit to it?

Thanks for schooling the blower newb in advance!

99.9percenter

iTrader: (2)

It is for added power. You can pulley down, or install a cam. Both will add power. Please do not over do a untouched engine with too much pulley or cam, you will hurt it$$$$.

DavidBoren

The purpose of changing your cam when adding boost is to make more efficient use of the increased air mass. Not only does it increase power and efficiency, but also safety and durability.

Your stock cam is designed to open and close the valves in a specific sequence in order to "trap" cylinder pressure in a naturally aspirated application.

You are now forcing a greater air mass into the cylinder, and thusly you are effecting the pressure inside the cylinder, as well as the characteristics of how that pressure builds.

If your naturally aspirated cam closes the intake valve too early, or opens the exhaust valve too late, pressure could build too much, too fast, and $#!+ starts to break.

A lot of naturally aspirated cams use way more overlap than boosted cams. Overlap in a boosted motor just lets your intake charge escape straight out your exhaust.

Most oem cams are mild enough and have little overlap, due to emissions, and work well for boost. That is purely coincidental.

A well designed blower cam will do far more than any pulley change, because it allows your engine to better use the boost.

DavidBoren

For best results (prioritized by importance):

Good cam.
Ported heads.
Smaller pulley.

Bob@BruteSpeed

iTrader: (16)

http://shop.brutespeed.com/Brute-Spe...d-Camshaft.htm

My blower cam has proven itself over the years. It has a great sound and really picks up the hp. Bob