***4agze turbo starlet boost problem!!!***

[stefegg89]

hi guys my starlet is having problems with boost its a 4agze bigport motor rebuilt and has a td05 turbo and 38mm external with link computer

i have had it at tms mechanics in param and they have checked everything apart from turbo well they have said i have enough fuel and air and no leaks in manifold or exhaust or no leaks out of wastegate

they put another boost controler on to see if my one was rooted but thats ok

the turbo doesnt blow smoke and they have had the car on dyno and has it to 8psi and thats all it will get to i brought a 12psi spring for wastgate to see if my wastegate was faulty but its not so now im stuck

has anyone ever had this problem or does anyone have a clue what it could be i guess im goin to have to take turbo off and take to diesel and turbo

cheers

[escortman]

so whats the actual problem?

[stefegg89]

im trying to get like 18psi not 8psi it wont go ova 8spi

[TRD_ZERO]

What wastegate are you using? Those style types are usually quite crappy and cause problems like that by leaking too much.

[tsoob]

what spring is in the gate? is it a tial ??

boost controller is the second place to look.

what about your plumbing, is it too restrictive? (i doublt it sounds like a gate problem more than anything else)

[stefegg89]

its a tial style wastegate it has been tested for leaking and it isnt leaking it has a 12psi spring in it
the boost controller is brand new from speedtech it is a stage turbosmart one that you have a switch in the car

[stefegg89]

the plumbing is like 2inch it isnt very big

[evil_si]

need some more info.

what was done with the standard wastegate? is it still there? is the original actuator still connected? is the flap welded shut, has the down pipe got a blanking plate over the original port??

if the standard wastegate is removed and block off completly next step would be
take boost controler lines off the external wastegate,
put intake pressure into the top of the wastegate and go for a careful drive,
see what boost you get then

if its the same. remove the wastegate and blank the port off, go for a careful drive and see what boost you get,

if it doesnt change check for exhaust leaks before the turbo
even a small leak can stop a turbo from spooling properly

and by careful drive i mean careful. with either of the methods i mentioned you should have no boost control, and this should pin point the problem area.

[stefegg89]

standard wastegate was taken off i packed weld in the back flap ov the turbo exhaust housing it has a blank plate ov the original port

so if i drive with the wastegate off it will stil go alryte?

by being carfull will i just accelirate slowly up the boost?

[escortman]

standard wastegate was taken off i packed weld in the back flap ov the turbo exhaust housing it has a blank plate ov the original port

so if i drive with the wastegate off it will stil go alryte?

by being carfull will i just accelirate slowly up the boost?

by take off wastegate i assume u mean take off the vac feed?

be best to do it on the mway in topgear so its easier to keep eye on boost

[TRD_ZERO]

take boost controler lines off the external wastegate,
put intake pressure into the top of the wastegate and go for a careful drive,
see what boost you get then

By doing that wont you get less boost as you will be getting full pressure to the wastegate and it will ope earlier, instead of having a boost controller in place leaking pressure making the wastegate open later?

[evil_si]

standard wastegate was taken off i packed weld in the back flap ov the turbo exhaust housing it has a blank plate ov the original port

so if i drive with the wastegate off it will stil go alryte?

by being carfull will i just accelirate slowly up the boost?

you will need to blank the wastegate port off,

by carefully i mean dont just give it full throttle as it may spike, accelerate slowly as the boost comes on quickly and easily the wastegate is the problem

[evil_si]

take boost controler lines off the external wastegate,
put intake pressure into the top of the wastegate and go for a careful drive,
see what boost you get then

By doing that wont you get less boost as you will be getting full pressure to the wastegate and it will ope earlier, instead of having a boost controller in place leaking pressure making the wastegate open later?

no the wastegate has 2 lines, top and bottom, the bottom line is the actuation line, the top hole is for boost control,

normally you would regulate pressure into the top hole to increase boost, using a tap or controller

however if you remove the lower actuation line and put full pressure into the top it should ensure the gate does not open at all.

[TRD_ZERO]

take boost controler lines off the external wastegate,
put intake pressure into the top of the wastegate and go for a careful drive,
see what boost you get then

By doing that wont you get less boost as you will be getting full pressure to the wastegate and it will ope earlier, instead of having a boost controller in place leaking pressure making the wastegate open later?

no the wastegate has 2 lines, top and bottom, the bottom line is the actuation line, the top hole is for boost control,

normally you would regulate pressure into the top hole to increase boost, using a tap or controller

however if you remove the lower actuation line and put full pressure into the top it should ensure the gate does not open at all.

Great stuff thanks.

[stefegg89]

my wastegate doesnt have a line on the side nipple could that be the problem it is not boosting problery?

the wastegate isnt even opening at 8psi is it cause i have a 12psi spring?

[evil_si]

can you post up a pic of the wastegate lines,

does it just have 1 line into the top? and nothing underneath / in the side.

[stefegg89]

it has a line in the side of the wastegate and non in the top..is that alrite like that??

[evil_si]

that is normal, but i take it your boost controller is on that line? if so id be changing that to start with

[stefegg89]

it is a t piece off the boost controller to the intercooler piping and to the side ov wastegate

[tsoob]

if you have a bleed valve for a boost controller do you have it the right way around? they have a little arrow that goes towards the acutator