i have a tt t34 with a 55 exhaust housing and a -34 . i can't get it to boost any more that 22 psi.
i've tried pulling the pipe of the turbo to see it boost's any more and i get it to 25 psi
i've checked for air leaks, removed the dump valve, tried another bost gauge but nothing changes.
what else can i try.

 

Check if youre wastegate closes properly.

 

ok thanks i was going to check this next.
am i right is saying if i take the pipe of the turbo from the amal valve it should hit full boost.

 

yeah wastegate should stay closed and pull itself right off the gauge
defo check that your wastegate is closing properly
if not a boost leak or you turbo is dying

 

Had a similar problem with mine, turned out to be the wastegate arm was bent and not sealing properly.

 

Think i need to check mine as well

Steve

 

i've just checked the wastegate and it looks like it sits flush when its closed, so i don't think its that.
does anyone have a tool to borrow me to pressurise the boost system (i will leave a depost). it goes onto the hose by that goes to the air filter from the the turbo.

 

Have you tried another amal valve? Is yours working?

If you've got the compressor directly connected to the actuator you'll get whatever amount of boost you've set by the preload on the actuator's rod. If you have the amal valve connected, the ECU will be able to control the boost as best it can. Don't forget that the ECU will (or should!) wind the boost down if the inlet temp appears too high.

Do you have another actuator to try?

Check your boost hoses for splits.

 

i thought if ya take the pipe off from the turbo with a -34 u would only see 1 bar of boost as this is what the actuator can hold

 

As I understand it, the actuator will hold whatever the spring/diaphragm can resist. If they're knackered, it won't hold as much as it would otherwise.

The vacuum pipe on the actuator allows some assistance in the form of vacuum/boost from the turbo or inlet manifold, so if that's broken there won't be enough assistance.

 

it's piped up through the amel valve, i have'nt tried another one but it does click when i plug it in.
i will borrow my mates actuator and give it a try, i've sucket on mine to see if the diaphram is split and pulled on the bar, its very, very strong.

i though if i pulled the pipe from either the turbo or actuator it should boost like mad.

 

a -34 can only hold/see a max of 1 bar boost hence the amel valve bleeds off the required amount of boost to keep the seen boost to the actuator below a bar until a determined setting

 

oh and what boost are you suppose/was holding?

 

The problem i had once was a leak in the fins off intercooler right at the botom,might be worth testing !!!

 

i have just run the engine in after my rebuild, so i've never set the boost

 

whats the chip boost set for?the chip might only be for 23psi

 

it should'nt be my intercooler, its a pro alloy one but you never know. thats why i want to pressurise the boost system to find any leaks

 

no sure 100% but it was running 26psi and was told i could turn it up to 28psi after i got my turbo rebuilt.
its a a1 rallysport chip for light blues and t34 turbo

 

hmmm!might be worth getting her set up!i presume the have the standard preload on the actuator of half a moon

 

yeah half a moon preload.

 

might be worth getting set up and too see what boost the chip has been written to run

 

My T34.55 max boost is 28psi, was only set up in December as well

Steve

 

i am going to get it set up but when i spoke to steve scott about the problem he said if its the turbo its pointless getting it set up. its a fair drive
he said if i remove the actuator pipe it should boost like mad. if not its either the turbo or a boost leak