Pictures of my Polo

[Kai]

Is this what we're talking about? (POD)



Dave

yep. thats the one

[Flaps]

What is the extra filter for? BOV?

[Kai]

What is the extra filter for? BOV?

I dont actually know. But it sucks in filtered air from the stock airbox. So i decided to put a filter on it. Everything seems to be working fine still.

[GT3]

It runs a second breather filter that sits under the main filter – that feeds the airpump for cold start emissions so it does not feed directly to the engine – none the less it needs to be filtered.

[MR-GTI]

Nice work bud..

So, Do tell about the flutter!!..

I'm very interested, I'm getting sick of the whistlle noice only !!

Regs MR-GTI

[Kai]

Okay.

So.

Remove your bov. Block all the pipes going to and from the bov.

This will cause a compressor surge. Thus giving flutterz.

Ive done this the last 40000kms. And ive done it on all previous cars ive dealed with. People say it will break your turbo and shiz. It just doesnt.

The Silvia s13 didnt even come stock with a bov. So soon as you put a pod on it flutterz.

[GT3]

Think of compressor surge as the point at which the compressor blades begin to “slip” in the air, losing their pumping ability, much like an aircraft wing loses its lift when it stalls. In a turbo, this happens in a series of bursts, as the blades slip, then bite, slip then bite. This sets up a pulsing wave in the turbo piping and explains why the sound has that characteristic “flutter”.

The interesting thing about compressor surge is that it occurs much more readily at low turbo shaft speeds. At these low shaft speeds, on road cars this is generally between 2000 and 3000 RPM, compressor surge is not much of a problem, as the loads generated by the surge are miniscule compared to what the turbo encounters at high boost. However, if surge occurs at high RPM and boost, it is possible to reduce the turbo life and/or damage the compressor.

[Kai]

Think of compressor surge as the point at which the compressor blades begin to “slip” in the air, losing their pumping ability, much like an aircraft wing loses its lift when it stalls. In a turbo, this happens in a series of bursts, as the blades slip, then bite, slip then bite. This sets up a pulsing wave in the turbo piping and explains why the sound has that characteristic “flutter”.

The interesting thing about compressor surge is that it occurs much more readily at low turbo shaft speeds. At these low shaft speeds, on road cars this is generally between 2000 and 3000 RPM, compressor surge is not much of a problem, as the loads generated by the surge are miniscule compared to what the turbo encounters at high boost. However, if surge occurs at high RPM and boost, it is possible to reduce the turbo life and/or damage the compressor.

Indeed you are correct.

As i said tho. Ive never ever broken anything and ive done it on all my cars. But it will reduce the life of the turbo. Not by heaps tho.

[SoVeReIgN]

It does reduce the life significantly, you just don't notice because it doesn't go *BANG* it just slowly losses its ability to pump air -
i.e You lose power.

Compression surge is when the air within the piping/turbo is going BACKWARDS over the compressor blades, 'slipping' is way too soft a word to use. The air is forced to go the wrong way because it has no where else to go (ie - usually let out by Diverter valve or BOV) and it flows back over/through the compressor blades that are trying to spin the opposite way.. Not only is it not good for the turbo at all but you'll lose power as it happens and it'll take your turbo longer to spool up.

I'm not saying don't do it (I personally love the noise), I'm just saying that its ****ing retarded and you'll need to plan for a KO3 replacement or KO4 upgrade much sooner than you would expect.

[Kai]

What a good excuse for a K04