Charlie spring user reporting in

[quk@sievers.com (Phil Payne)]

In message <Pine.SOL.3.91.960901102158.21169C-100000@apollo> "Graydon D. Stuckey" writes:

> 	I have a Charlie spring with two shims, plus a regulator on the 
> top side of the wastegate.  No solenoid at all.  My boost control is 
> entirely mechanical/pneumatic.  So far it is very reliable, but that 
> doesn't mean it won't fail.

If it does, the fool pump shutoff should still save your engine.  As long, that 
is, as the ECU is being fed good information.

> I think I am going to try the stock spring 
> again with the solenoid in place, and use RDH/SJM's ECU probing tricks to 
> control boost.  I _think_ it will spool up faster.

That's the theory - positive holddown versus Hook's law.

Should we eventually develop some sort of system condition indicator based on 
the overboost control valve's duty cycle, you'll benefit from that too.

--
Phil Payne 
 phil@sievers.com 
 Committee Member, UK Audi [ur-]quattro Owners Club