Do boost leeks cause irreparable turbo damage?

[Blue_Thunder]

With the N75 disconnected, the wastegate will be fully open won't it?

[s4woody]

dnt you mean closed..i thought the N75 directed vacuum to the wastegate to open it not close it..aint it closed until opened..

[ZeroK66]

The wastegate is set at approx .5 bar - that is the spring tension on the wastegate itself. The N75 valve "bleeds" air to keep the wastegate shut over pressures of .5 bar in the engine. IE: If the ECU requests 1Bar of boost, the N75 will bleed .5bar of pressure + .5bar on the wastegate at which point it will start to open?? I hope that makes sense - that is my VERY simple understanding.

When disconnected the N75 does not bleed any boost and so the car is limited mechanically by the spring tension on the wastegate at .5bar boost.

[Dippy]

I thought it was 0.4 bar - that's what my gauge read when I had limp mode.

Yes I am the odd one out. I have still got my original turbos and they don't make any significant noise. And what I mean by significant is that I need to drive with my window open in order to hear the feint whistle as they spool up.

[hethers]

Possibly dumb but relevant question - if you rev the (already warmed up) engine in neutral, what happens to the turbos? Do they spool up? Do they generate boost pressure? If there was nasty turbo noise, would it be audible with the car stationary but revved??

Hope this makes sense...

[derdle]

I don't know the answer...but my instinct tells me that the turbos won't spool up much...rationale?....no load on the engine and therefore low fuelling/gas requirement.

Now waiting to be told that my reasoning is totally up sh*t creek and so I can something new today!

[Blue_Thunder]

I'm with you on that one Derdle (aka 'The new Dr.Al')

[derdle]

aka 'The new Dr.Al')

Oooo no.....I don't want the responsibility of that one thank you! just simply applying my (crap) logic!

[Blue_Thunder]

In response to my own question posed as the topic of this thread...

The answer unfortunately for me appears to be a big fat annoying YES!!! Less than 1000 miles (and possibly even less than 300 miles) with massive boost leaks can kill even a mighty K04.

[Philws4]

Possibly dumb but relevant question - if you rev the (already warmed up) engine in neutral, what happens to the turbos? Do they spool up? Do they generate boost pressure? If there was nasty turbo noise, would it be audible with the car stationary but revved??

Hope this makes sense...

I have a boost gauge fitted to my S4 and if you rev the engine in neutral there is no significant boost registered by the gauge.So i would agree with Paul and say that the turbo's don't spool up.