Iv been told that i get compressor surge on occasion coz i have such a short air intake to the turbo.

I dont understand how this is able to happen?

the air intake is customized for the angle mount to a vf34... HKS mushroom filer and about 40cm of piping to the turbo.

When do you get compressor surge? If you're talking about off-throttle "compressor surge", its a BOV issue.

Proper compressor surge has to do with the turbo flowing more air than the engine can ingest, causing a pressure wave trying to go back into the compressor outlet.

This is rare and only occurs when the turbo isnt the correct size for the motor...all turbos have a surge limit, as shown on their compressor maps. I doubt your VF34 is experiencing this

its when generating boost. Apparently it cant control boost properly becoz the air tract is too short and is "surging"

using a 3 port.
Its making a fluttering noise - which i assumed was coming from the 3-port, apparently its coming from the air intake....
:|

that fluttering noise is coming from the solenoid from the 3-port..

Do u get it when higher in the rpm and nearly full boost??

I had that on my old car and all it is is it opening and closing..

Doubtful that the length of the tract matters.. Take off the intake and put some mesh in its place take it for a spin and see if the sound increases (only work if ur running map)

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I'm a jockey kunts...

As joe said when getting off throttle its bov issue being to tight.

But yours is different are you talking about when u hit full boost it surges?

Mine does it in like 4th and 5th and im told its the wastegate gases and turbo gases getting mixed up because i have a bell mouth dump apprently external wastegate will fix the problem?

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M POWER

only happens when boosting to full boost in most of the higher gears
Therefore it sometimes has trouble keeping stable boost control... been told its coz of the short length of inlet.

What is the internal size of the pipework?

2.5" piping from the filter then decreases to the diameter of the turbo mouth about 10cm b4 it.

the MAF housing is from the HKS filter kit piping for the wrx

My car does this (I think). But I may be mis-interpreting what your saying though Tode. I remember Clints RA did the same thing (also running a VF34).

The AVO boys call it wastegate chatter. AVO have a fix for it - and I'm told porting the wastegate in a certain part of the dump/housing fixes it.

Have a read of the following:

http://www.rexnet.com.au/forum/index...stegate%20port

http://www.rexnet.com.au/forum/index...te%20port&st=0

Nothing to do with the intake as far as I know - like I said though it may be a different issue. But from what you havbe described mine does the same thing. VF Series turbos are renouned for it. Still holds boost fine though and doesn't appear to have any negative affects on performance.

If you want/need more info call Steve from AVO in Melbourne. He ran me through the process over the phone once.

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I don't mind coming to work, but that eight hour wait to go home is just bullshit....

wastegate is ported already. dont think its that but hmmm
i noticed the problem when i switched to the 3-port and its jus got worse with the vf34 than the FP green i had