boost verses volume????

[Evil Otto]

boost verses volume????

well here is my ? i have a 96 12v with 370 inj. 3000gsk, hx40, ats exhaust manifold, 5'' exh all heat wrapped. don't know what was done with the pump? but it put out 401 rwhp last fall and pushed 45lbs of boost. over the winter installed dd cam and a banks twin ram intake. now i lost 12-15lbs of boost. the truck seems to pull just as hard. but with out the boost. now i know boost= pressure and pressure is a resistance to flow. by adding cam and intake i reduced the resistance increased the flow allowing more volume. allowing air to move with less resistance caused the drop in boost psi. the truck still pukes a lot of black smoke. can i adj the waste gate to spin the turbo faster = more boost to get it back to 45-50 psi. i think i have enough fuel to burn. or will need a new turbo? and if so do i turn the waste gate rod in or out?



ED

 

[KLockliear]

The better question is what did EGT's do with those mods? If the boost fell, but EGT stayed the same or got lower, you did a good thing.



The compressor map of an HX-40 compressor gets away from it's efficiency at around 38psi, so anything over that is just spinning it up and creating more heat (not to mention over-spinning the shaft which will eventually break it).



Given the power level, I think the HX-40 is the right size for the job. A bigger turbo would be laggier off the bottom and will make more EGT towing (part throttle).



What is your goal from here out? More power? Smoke reduction? Nitrous?

 

[Evil Otto]

my egts went way down had no problem pining the guage. now have a hard time hitting 1250. i am after more power. if i have that much smoke i could use some more air. i don't tow with the truck just beat the crap out of it. now if i can stop breaking trans parts. i will take it to the track and see what she can do.



ED

 

[KLockliear]

That's a good thing then. Shoot for 38-40psi MAX and leave it alone. At your power level... that's it for you.