so heres whats going on, ive got a 2.4 cavy with a 5 spd, a t3/t04b turbo with an internal wastegate. the guy said the spring is suppoesd to be a 5.5 psi spring, with the mbc on its lowest setting im only seeing 4.5 pounds, maybe the guage is off, lets say it is for arguments sake. up until about 30 minutes ago i was running a homemade style mbc, now the problem was that once i got to about 9 psi i coudnt get it to go any higher, it will when the temp drops and itll see a couple more pounds, so i thought maybe the mbc is junk so i went out and baught the turbosmart unit. well turns out i can completely adjust everything boost wise with this thing except when it comes to going past 9 psi, right now im about 3 full turns up from where i first saw 9 psi and it wont go any higher, actually itll hit 10 and then taper to 9 and then to about 8 just before im ready to shift gears. im running the vac line right from the compressor housing. i dunno what the problem is, could it be the internal spring has seen its limits or something and thats why i cant go any higher? should i keep turning and see what happens? my old home made mbc would go about 1 pound per half turn or so and i was up 4 full turns on it and still not going any higher.
parting out my built and boosted 97 z24 so4x4.com/cavy.html for pics and a parts list
check for boost leaks in your charge pipes... do a compression test of the charge pipes....
what kind of BOV you running ???
are your t3 connection (or whatever ur runnin) bolts all tight and secure.........
is ur wastegate adjustable.........
you MUST understand and you probably already do... your turbo's PSI level is controlled by the wastegate diaphram..... so if your having trouble with boost and one of the things I mentioned aren't wrong... get a new gate......
Good luck...
Lee
JDM Civic Hatch
Status: Parting Out Turbo Kit....
14.224 @ 102.01MPH @ 5.5psi.... 2.3 60'
Next: Civic JDM B16a2 w/GSR LSD Turbo - Goal 300whp 1400lbs...
Hmm i kinda had the same problem, my wastgate spring was supposed to be set at 5 or 6 i dont remember, but i never saw above like 3or 4. I got a turboX mbc and ive since put it up to 10 alright, as far as i know the spring in the wastegate shouldnt make a difference at that point. it doesnt have limits per se because the mbc is just holding it open longer. Someone please correct me if im wrong, but i thought my spring was sticking for the longest time, because my vacuum was stiking at like 10, then after i boost it would drop back down to 15/20, until i hit 10 again, then it would stick. turned out it was a vacuum leak, If your boost is tapering down, thats probably not a good sign, check for a vacuum/boost leak somewhere.
ya see I thought book leak at first too....
Check your ride out again and get back to us...
Lee
JDM Civic Hatch
Status: Parting Out Turbo Kit....
14.224 @ 102.01MPH @ 5.5psi.... 2.3 60'
Next: Civic JDM B16a2 w/GSR LSD Turbo - Goal 300whp 1400lbs...
sounds like ur bov isnt staying closed
slamming 2 gen cavi
thanks for all the info. ive toghtened down all the t bolt clamps already jsut oto make sure its not coming fom there, im gonna go over the vacuum lines again tomorrow and tighten them down and hope that i can make somehting out of this. thing is, the first nite out, i turned the boost controller up too far and we saw roughly 15 psi until i let off, and on a cold nite itll go higher, guess its a mbc thing to creep when its cold out.
ill tighten up the connectors on the vac lines and see if i can make anything of it, although im at a point wher ei might jsut gte a new wastegate with an 8 pound spring in it.
but i tell you, going back to 4.5 psi was so god awful slow, oh man it felt like i welded the exhaust shut, lol
parting out my built and boosted 97 z24 so4x4.com/cavy.html for pics and a parts list
yeah thanks for the call bud, i might be doing the old hammer tothe cat trick this weekend, hehe, actually ill see if shes glowing tonite when i go for a coffee, always a good way of checking
parting out my built and boosted 97 z24 so4x4.com/cavy.html for pics and a parts list
im gonna try to find time tonite before work to pul lthe vac line off the mbc and see if i can get more boost, gonna watch the guage like a hawk and make sure it does go all loopy on me and peg the needle, would be the best 8 seconds of my life though, lol.
another thing i was talking to sunfighter the other day again about adjusting the actuator arm, if i were to put a real small amount of preload on the spring what can i expect in terms of negative effects? i think chris had mentioned what would happenbut god knows if ill ever remember, brains working overtime the last week so things are slipping out.
parting out my built and boosted 97 z24 so4x4.com/cavy.html for pics and a parts list
You should be fine adding some preload to the spring. My actuator arm is threaded and i have had the boost anywhere from 5-9psi on just spring pre-load. Just make sure you don't load it to the point where theres not enough throw left in it to open the swing valve all the way.
<img src=http://home.comcast.net/~richnj221/smiley.gif>
yup if he had an adjustable gate no problem.... however when "preloading" the spring you make the arm that is threated rod longer or shorter.... you should only have it so the gate is close but just barely.... or lower the psi as much as possible and then use the MBC to control it .... or vise versa... just make it really high and tight and then use the mbc ....
Lee
JDM Civic Hatch
Status: Parting Out Turbo Kit....
14.224 @ 102.01MPH @ 5.5psi.... 2.3 60'
Next: Civic JDM B16a2 w/GSR LSD Turbo - Goal 300whp 1400lbs...
thanks for the input, gonna put some preload on it today, a half turn or so and hopefully i can get some more adjustability out of it, i only want 10 pounds, i catch that on a cold nite and its a safe good strong power. but knowing that i can go more if i have to is even better
parting out my built and boosted 97 z24 so4x4.com/cavy.html for pics and a parts list
well i had a look, looks like the screw on my actuator arm had backed off and probably the arm itself had unthreaded a little from the threaded sleeve, so i gave it some preload and shes holding boost now, 10 psi, dman its fun
parting out my built and boosted 97 z24 so4x4.com/cavy.html for pics and a parts list
bout time you got it figured out
SPD RCR Z -
'02 Z24 420whp
SLO GOAT -
'04 GTO 305whp
W41 BOI -
'78 Buick Opel Isuzu W41 Swap
yeah i know, been bsy with work, dont get much of a chance to work on my car anymore. but theres a dyno day next weekend, see what i can lay down
parting out my built and boosted 97 z24 so4x4.com/cavy.html for pics and a parts list
