im having trouble getting my car to make boost.
its a cos with a t34.63
there are no leaks in the system, ive pumped the whole setup up to 3 bar with a compressor and its fine.
it very very slowly drops boost, takes a good 2 mins to loose all the pressure, but thats testing from the turbo to the engine, inc. inlet manifold and cylinders, with throttle open or closed, you cant hear or feel any air leaks anywhere, i think its going through the engine as it should. but with the engine running it would be using the air, so as it flowed in it would be a lot harder for it to leak out.
now when i drive down the road it doesnt make more that 1.8bar peak, but then drops and holds 1.4ish.
even if i disconnect the actuator pipe.
turbo was bought new, has a new -34 actuator with 6mm preload and has done about 1500 miles at under a bar no hard work.
does this mean its a dodgy turbo?
i rang turbo dynamics and they said you cant bench test a turbo, the only way to test it is to take it apart and check tolerances. but he did say if it was faulty it either wouldnt make boost at all or would smoke(which it doesnt) and theres no play in the shaft at all.


car is chipped and built to peak at 2.2bar and hold 1.8bar
any1 got any ideas? im all out.

 

what boost control are you using?

 

well it was running an amal valve but that died, (blew apart then electrics failed)and it never made the boost with that fitted
so i put a t piece in the actuator pipe to see if i can get it to make/hold boost and it still doesnt even with the t piece jetted down to 2mm on the actuator and compressor side and a 5mm bleed to atmos
and then i tried taking the boost hose to the actuator offf and blocking it, so it ran the actuator alone so in theory should make loads, and its still the same
which says to me, dodgy turbo, or a leak which i tested for and cant find.

 

must be worth just whipping the exhaust off and checking the wastegate is seating correctly as a first check then

 

I thought that, I had it apart a few weeks ago and it looks like it seals ok and doesn't have any cracks around it. Could quickly whip it off again and clean it up/double check I suppose. Especially if I'm sending you the chip back, cars off the road for a couple of days anyway lol.
I think that's ok tho.

 

up for the early morning crew