Help !!!, 1G + New intake + New Exh. Manif. does not come on boost.

[romelan]

Hi, I have, almost, finished the single turbo upgrade to my Supra Ga70 1989, 1GGTE 3rd gen. After a lot of work, the engine start and idle perfectly ~750rpm (in the first run !!!), it was running several times for 20 minutes each one to check leaks (air, oil, water) and computer errors with no critical problems.

I pulled the car out of the garaje and start to drive around the block succesfully (30 minutes), but when I try the turbo start to boost in thirth up to 4000rpm it does't make any boost, it goes from to around 20 miHg (vaccum) to almost 0 psi of boost easely but doesn't pass from this mark (turbo light does not come on) . The car have good response from idle to 3000 rpm but from that to 4000 it feels slow to rev., maybe due to the turbo doesn't come on boost to help with extra power.

The down pipe from turbo to exhaust is not completed it reaches under the car but is not connected yet to the rest of the system, sound a little grove , the o2 sensor is located around 6.5" from the turbo and it is sending signal to ECU but watching A/F meter, only the red lights comes on and moves a little up and down . The SAFCII is setted to -29% in low rpms and low load (with stock turbos and intake this configuration works fine). Stocks injectors was 310cc/min green pale.

The car was pulling 14psi of boost with stocks turbos, 440cc injectors, SAFCII, 3inch RS*R exhaust, K&N air filter, aftermarket intercooler, steel 2" pipes.

Have anybody some idea what is the problem ?

List of mods.

Custom exhaust manifold, almost equal lenght, short runners 1.5" stainless steel pipes. Stock measure internally a volume of 550cc in each turbo manifold the new has around 670cc (3 runners + collector) middle turbo mount
Deltagate II external wastegate 5psi stock but with the boost connector (1/8NTP) connected to intake plenum.
Turbo (I know, I know, cheap and not good quality, I am crossing fingers to have luck. First turbo project) Super T70 from SSautochrome. Compressor .70, Exhaust .84 (divided). I ordered .50 and .70, but I received wron item !!!
Custom intake manifold, front face, ~3.2 liters (stock ~2 liters), short straight tappered runners (~4inch from flange to thrumpets), rounded machined thrumpets (20mm high) inside plenum but flush mounted, no TVIS, supra turbo 7mgte butterfly, stock Idle valve, without cold start injector (lowest temp registered in my city is around 10deg., it is sunny and hot almost all the year).
440cc injectors from a 7mgte turbo
High pressure Fuel pump Walbro 255lph
Aftermarket fuel pressure regulator (set to 28-30lbs at idle)
Intercooler 24" x 12" x 3", 2.5" inlet and exhaust
2.5" alluminum pipes (more than 1 meter shortered path compared to stock 2" system)
Stock computer with SAFCII
Custom engine Oil radiator 8"x 6"x 3/4", side mounted.
16" Electrical radiator fan

[oldcorollas]

coupla things...

is wastegate stuck open?

is turbo stuck..... take off intake pipe and try to spin it with your fingers..

if there is no boost at all.. maybe turbo is not turning at all... or not turning fast enough...

forgot to hook up all the intake pipes?

[romelan]

I have checked the wastegate before installing, the spring is hard to move and it is closed. I will put some tape on the wastegate exhaust to check if the valve is really closed or not

I have checked the turbo, spin with no problems. I can hear it starting to spool. I have tested the car without hood.

Yes, the turbo is a little big for this engine but I was reading other projects that uses this turbo and they are making boost.

Pipes joins checked, I will re check this night.

[oldcorollas]

hrmm.. chuck it on a dyno to get some real load onto it, check the AFR's properly and have a fiddle.. if it still doesn't boost then turbo is wayyyy too big or something is very wrong...

did they forget to install a turbine into it?

[stradlater]

Yep, DEFINATELY check the wastegate on this one. I had very similar problems. the Thing just wouldn't boost. Turned out the wastegate was open..

Turbos are pretty simple things really, if gass is allowed to go through the turbine wheel, it will then spin the compressor wheel and in turn make boost. It's a multiplying effect. About the only way your NOT going to make boost is if your loosing air. Somewhere....

[stradlater]

PS: It'd have to be a freaking BOAT turbo not to make some minor level of boost at higher rpm... I mean hell, my turbo is WAY too big, and it makes full boost at around 5000 rpm, so it'd have to be MEGA huge not to have ANY boost.

[romelan]

Yes Stradlater, You are right about the size of the turbo, mine should be making at least some boost.

Wastegate is the first thing that I will check tomorrow night, I need to fix a hose or connector from the adaptor for the oil cooler, today before I start to test the car in the street, suddenly pop out and about 1.5L of oil was loosed, fortunattly I stoped the engine quickly to not damage the engine (lucky day !!!)

Another thing that I will check is the timing, during my first test the Te1 and E1 pins was connected and forgot pull out the wire to drive the car, so I think that this was not leaving to the ECU change the advance to manage the boost. I have buyed a tool to measure the idle timing to ensure if this is stock (10deg) or not.

I am attaching some pics to check the state of this project...

[stradlater]

A) That turbo is not too big at all.

B) Check that your doing your boost control properly. If I can see the line properly, it doens't look like it is.. Just try running an un-interupted line from the base of the wastegate can to the manifold. The boost control with the wastegate like that works by bleeding off the air to the top of the can, not by modifying the reference signal to the base of the can.

But yeah, check that your turbo can actually spin, it looks second hand after all.

[MR 1JZ]

what turbo is it?

it looks like one of those Xspower T70's

[thechuckster]

But yeah, check that your turbo can actually spin, it looks second hand after all.

as like wilbo found, you discover that the zorst turbine has self destructed leaving only bits of blade attached to the spindle.

[romelan]

... Yes It is similar at those XSPower that have no good reputation..., my fault, this is my first turbo project and I am crossing all my fingers with hope to be lucky about this turbo.

One year ago I started this project, learning about the process but four months ago when I had started to build the custom manifold I read several bad things about this kind of turbos..., late to stop the project.

Another problem is that in my country (Bolivia) nobody sell custom turbos, all that I found was stocks small turbos.
----

I will re check the manual for Deltage installation, Stradlater cuote (B) have a sense.

[MR 1JZ]

hmmmm, maybe remove the exhaust housing and the comp cover and see if both wheels are intact...

[emp?]

ok my t70 comes onto boost really slow, like 3psi @ 4000rpm, and about 24psi by 5000rpm
so the turbos are big and rather laggy on a 1g

[stradlater]

big and laggy yes, But what you said there was definately not 0psi the whole time.

[Hydra]

Where are you taking the boost reading from?

Make sure all those lil exhaust gaskets are sealing nicely, this has caused issues for me once before (one of the nuts holding a turbo on managed to work loose!)

Is the engine revving freely despite making no boost? Maybe try disconnecting the wastegate actuator hose and see if things change at all