Well, i fixed the boost problem on my friend's LS/14b hatch...the wastegate was being held open. Only problem is now that it starts spooling up around 1700 rpm, and makes 8 psi by 2800. You have to feather the throttle in just to keep it from breaking up around 4000 rpm, and it breaks up really bad after that. I changed the wastegate line, and it helped a little bit (old one had a leak in it) by slowing down spool time a hair. I also retarded the dizzy timing completely cause of the vafc he's running. It pulls hard as hell now until about 4000 rpm, and then feels like it drops like a rock...no power past that, and with the new line peaks out at 6.8 psi. What would cause it to drop off so drasticly like that? And while i'm at it, we're going to change the plugs from stock to a colder set...anyone have a part number for 1 step colder plug for an LS, or a better plug to run period? Also, could the stock plug gap have anything to do with it breaking up and bogging out? The local parts store looked at me weird when i asked for them, so they obviously have no clue. Thanx!

 

Yeah, we're dropping the gap down today. I remember with my old z6/14b the stumbling issue stopped when i dropped the gap, right about the time i think you were having the same problem.