Originally Posted By: Mean buzzen half dozen A.K.A. Hank
Just thought about the comment about the newer 06 & newer head flows 50% better on the exhaust, efi-diy,,you stated it will help w/the turbo spool up better.
I disagree,ports being bigger ,less velosity,slower spool up.
A few ways to bring the spool up is by Nitrous,smaller turbine housing (I recommend),or a loose converter,not being a BB turbo,3500 stall is aprox the min. stall needed,that's if you want to be able to boost launch. Two cents thrown.
Goodluck!
MBHD
NO2 yep - agreed. Smaller turbine housing - good chance this will come to pass Higher stall - don't think I'll be able to get away without it - maybe a 100HP hit it'll shock the coverter enough..(maybe boom ..) Last time out it was just a 20HP shot.
AS for the ports for spooling yes and no - yes velocity is a good thing, but you also need volume... the small ports are so darn restrictive that I'm thinking the its choking the engine pretty good. We'll find out once the built engine goes in.
Once a gas stream reached sonic velocity - its really hard for an orfice to pass more gas.
The other item that you wouldn't know about is the internal passages in the turbo manifold are sized for the 90% of the later port. So on the early head the velocity falls off. So with the later head the gas stream will have to increase velocity as it enters the manifold. Worst case it'll be slow to spool but run like a raped ape once the boost comes up...
Last edited by efi-diy; 10/11/0802:09 AM.
51 GMC 4.2 turbo Can't solved today's problems using the same technology/thinking that created them
..) Last time out it was just a 20HP shot.
