ok here is the deal... When I built the k car i had inconsistent boost... Id sometimes get 10psi... sometimes Id get 15psi... I chocked it up to the TU 3" SV puck being loose and catching on the hole... I then fixed that (stainless wire behind the puck retainer) and it was all tightened up but still had a little play to seat flat against the ex housing. still have inconsistent boost control. 1st gear i never get full boost but i contribute that to the lack of loading and the slightly rich fuel curve... no big deal. ive tried different graingers and cleaned them and none are consistent. sometimes I get a nice, clean 15psi with little spiking when I roll on the throttle, sometimes when I have 15psi in 2nd and then I shift to 3rd I get 10psi once shifting etc. annoying.
fast forward to today. I just built a sweet new boost controller (i'll post about it later) and I install it. again... inconsistent boost control. sometimes 10, sometimes 17 (where I set it) and sometimes 15. sometimes if I roll onto it and it boost comes up really fast it will be more consistent.
here is the setup. TU 3" SV (doubt thats the issue), T1 large wastegate can on a stock T3 with the .63 a/r housing. I blew and sucked on the wastegate can feed hose and I cant detect any leak in the diaphram. I have short hoses from the boost source and the MBC and to the wastegate can... 12-15" tops overall. I dont think the boost controller leaks. I put in the ball and tightened down the allen screw and I blew on the input side and its air tight from what I can see.
only potential problems... I have the radio shack alligator clips holding the wastegate arm to the SV peg. possible binding? dont think so. I polished the arm at the end to make sure its smooth.
my boost source is a T in the vac line to the brake booster. I dont think thats an issue either. I just dont know what it could be. everything is cleaned out with electronics cleaner (mild solvent) and dried and reassembled and it still does this crap. all of the graingers and mbc's that ive put on the car have been inconsistent so I think it has to be some external source.
oh yeah.. I have a small restrictor used as a bleed between the MBC and the wastegate can to make sure its not held open.
any possible solutions? i think I might go to my buddies house and use his compressor and do some serious tests on the whole system.
thanks
Brian