Turbo Change = no power

[samsalter]

Guys,

I have recently changed a failed turbo on my A3 1.8t quattro. (this was a massive ball ache with the AWD system)
I now have an exhaust leak as 2 exhaust manifold bolts snapped.
also have a water leak, from the turbo water inlet.
Took it for a test drive regardless of the leakage, and it has no power!
Turbo is spooling up, sounds so good
this car was relatively quick before, but now its like a 1.6 eco diesel. (slow!)

What could this be?
I thought maybe the exhaust needs a blow through as oil would have flooded it previously?
or
the vaccum hoses have been put back incorrectly?
or
the boost is not getting from turbo to inlet?

any suggestions?

 

[<tuffty/>]

If you have a preturbine exhaust leak then this will affect the turbo's ability to generate boost...

What boost are you running at the moment? boost gauge or logging in vcds will help

Plumbed N75 pipework in correctly?

<tuffty/>

 

[samsalter]

I'm going to plumb and old boost gauge to find out the boost pressure.
I am unsure about the N75 pipework, I did take a picture before removal, but the pipework is like a puzzle.
What is the N75 anyway?

 

[<tuffty/>]

N75 controls boost... kinda key to the whole issue here at a guess

Long spout goes to the TIP, spout directly opposite goes to the actuator, boost goes to the spout on the bottom

<tuffty/>

 

[samsalter]

Tufty, are you sure?
This is the picture I took when I bought the car as a non-runner


See how the opposite pipe goes to the boost pipe not the actuator?

Like I said above, this car was a non runner so that picture may be wrong. Can you confirm this?

 

[Stuart B]

I am not sure where the turbo outlet pipe is supposed to go maybe a probe into the TIP, but not into the top of the N75.

 

[<tuffty/>]

Ok... to clarify as I can see a little ambiguity creeping in from peoples perception of N75 orientation....

<tuffty/>

 

[samsalter]

The above picture seems to be the general orientation.
Here is a fitted example.



Notice the red pipe goes to opposite(boost)
Top goes to actuator
Bottom goes to tip

I just need to check mine is in the correct way now with long pipe going down into tip

 

[badger5]

I am not sure where the turbo outlet pipe is supposed to go maybe a probe into the TIP, but not into the top of the N75.

long leg of n75 into TIP - simples

 

[badger5]

The above picture seems to be the general orientation.
Here is a fitted example.



Notice the red pipe goes to opposite(boost)
Top goes to actuator
Bottom goes to tip

I just need to check mine is in the correct way now with long pipe going down into tip

Forget TOP and BOTTOM fella..

Look at N75 pictured. It does'nt get any simpler than that to confirm orientation