b16g1teg

i'm running a B16 under 88 integra's hood since last one year. boosted the stock engine using EVO FMIC, 450cc DSMs, VAFC Hack, FPR, custom manifold and Nissan V27 turbo (boost was 8psi)
i use to feel not much ppower in third/fourth gear therefore i bought a new turbo formyeslf and it was a 16g(big). therefore i changed the manifold and got it designed like "ITTI" (means two 'T' connectors with two 'L' bends, i guess this is LOG style manifold?)
now my problem.
There is no leak in piping, rubber bends or in my intercooler. i use to get solid 8psi of boost with the older turbo. but after installing 16g with new manifold and downpipe. with stock actuator which was feeded from the charge pipe (hotside)
My first run with 16g
As soon as i floored it i just had 3/4psi , i was xpecting something around 8psi straight.
Then i UP the boost by tightning up the acctuator but still the boost was around 4psi
checked everything but notthing seems abnormal nor did i find any leaks. So in order to check how much is the turbo working i just opened up the acctuator pipe in order to monitor boost and floored it in third. boost went up to 15psi so i took the foot off my accelarator. So i bleeded the boost from the acctuator with a T fitting having a valve bleeding boost into the air. RESULTS. NO Bleed= 4psi, halfbleed=5psi , full bleeding=7psi..... even this 7psi was not constant/stable, had 5psi in first, 6psi in second in third boost went upto 9psi then came back to 7psi .

with acctutor (vacuum not connected) it use to spike upto 15psi and then came back to 6/7psi stable..... however in this case turbo should be giving full unlimited boost which my 16g didnt
im totally confused cuz im sure its not my acctuator, my turbo wastegate was perfectly fine, turbo spinsup real well and spins on idle too, turbo does not have shafplay(veryyyy minimum), there is no leak in pipe(hotter side or colder side) nor in my intercooler.

kindly help me in diagnosing the problem im fuc***up
plez help

coneheadsracing

Very confusing man. Okay so assuming all your pipes are solid. What wastegate are you running? Stock one. Where is your vacuum source for that. Are you running a boost controller at all? What do you have for a blow off valve, and how is that hooked up.

I've had a manual boost controller hooked up backwards and boost was up/down, never constant, spike 19psi, then fall to 12.

I've had charge pipes blow off, major turbo spinning, but no boost.

I had a o2 bolt/plug come out, made good boost still, but had more delay to it, that was wierd.

If your using a stock wastegate, make sure the flapper is tight, any leak there will cause you problems.

b16g1teg

Its its very confusing for me too

Yes!! all of my charge pipes are very much solid with no leaks (im damn sure on this). im not running the stock wastegate of 16g, instead i have another very much working wastegate mounted in the same way(likestock acctuator) on 16g. that wastegate works real well (i checked it myself, was pretty solid)
Vacuum source for wastegate acctuator is on the charge pipe(Hotter side) just after the turbo.
I also have a BOV which is working fine and vacuum/boost source is connect to it. its on the charge pipe(colder Side) around 15inches before the TB.

Boost controller is off now. even with the acctuator connected to the above specified vacuum source it gives me 4/5psi.

and with open wastegate acctuator(no vacuum lines connected) it goes upto 7/8psi in first , 10/11psi in second, 15psi in third but in third it drops back to 6/7 after hitting/holding up 15psi for a couple of secs .

I can hear huge turbo surge but not much sound in blow off valve.

Im thinking that turbo is spinning and producing boost but maybe an exhust realated issue???? restricted exhust??? car is quite like hell even in boost. i think i must give my car a run with open down pipe... what do u think?? cud this be the problem???
or my turbo manifold???
guys plez help

coneheadsracing

If you hook up the wastegate, with no boost contorller, what is the boost. If its consistent, and when you hook up the controller your boost goees all crazy, then look into the way you have it hooked up. Otherwise, i'm stumped, maybe some pics of the setup?

Your car will be pretty quite with a turbo, but what is your exhaust setup.