Fwd: Overboost Protection

[ScharfR@aol.com]

A good friend of mine recently bought a '91 200TQ.  So far, so good, with the
exception of the problem he details below.  I'm no turbo-meister, so would
appreciate it if anyone has some helpful suggestions.  The car does have the
TAP chip, but I don't know what other modifications are in place and the car
is out of state.  Thanks for any help. [btw, I have already informed him that
the "self-actualized" radio is a different problem]

<< What is the control mechanism that protects from too much boost?  I know
 the wastegate in theory mechanically limits the maximum levels that can be
 achieved.  If  that fails, what happens next?
 
 The 200 runs great except sometimes when on the gas in 2nd or 3rd when the
 turbo has time to build up to max boost, there is a violent cut off in what
 seems like the ignition.  The motor totally shuts down for just a fraction
 of a second then takes off again.  The impact is so hard that the radio
 will actually change stations if it's on!   Sometimes will happen once,
 sometimes more than once. >>


---------------------
Forwarded message:
From:	JSeaman@compuserve.com (Jeff Seaman)
Sender:	JSeaman@compuserve.com (Jeff Seaman)
To:	ScharfR@aol.com (INTERNET:ScharfR@aol.com)
Date: 97-11-19 13:33:49 EST

Bob:
Another car question: 
What is the control mechanism that protects
from too much boost?  I know
the wastegate in theory mechanically limits the
maximum levels that can be
achieved.  If  that fails, what happens
next?

The 200 runs great except sometimes when on the gas in 2nd or 3rd
when the
turbo has time to build up to max boost, there is a violent cut off
in what
seems like the ignition.  The motor totally shuts down for just a
fraction
of a second then takes off again.  The impact is so hard that the
radio
will actually change stations if it's on!   Sometimes will happen
once,
sometimes more than once.

I'm sure I will break something if this
keeps happening.  Any ideas?  (The
guy at TAP didn't have anything
helpfull.)  

I'll even take the name and number of a 200 Turbo expert if
you know one so
I can chase this myself.

Thanks,
Jeff