[Biturbos4] Turbo questions

[Steven Lin]

Robert Bullivant writes:

> What gives with Audi's turbos and their apparent lack of staying
> power?

It's not so much the turbos themselves but all the associated
plumbing.  There are a quite number of weak points, including the
Throttle-Body-Boot (TBB), F-Hose (MY2000 only), By-Pass Valves (BPV),
Intercooler endcaps, and the previously mentioned oil return lines.
Except for the oil return lines, failures in any of the other areas
often results in a boost leak, which can lead to overspinning of
turbos.  That's usually when your turbos go bye-bye.

There also seem to be some number of occurrences of FOD (Foreign
Object Damage), where something is sucked into the turbos.  This
usually results in a more violent form of turbo death, with big clouds
of smoke.  I'm not quite as familiar with the actual causes of FOD.

-- 
Steven