re. Stage II on MAC 11 -> FAQ

Ben Swann bswann at
Wed Dec 18 10:39:03 EST 2002

[I'm planning on getting the QLCC code pretty soon and did some research in
archives today. As usual it just made me have more questions. Here's what I
think I understand: the QLCC chip will give you 1.8 bar.]

Yes - in and of itself with nothing else, and yes you can use lower octane
than 92, but don't.

[ Paired with a 1.8 bar spring the boost will spool up faster.]

Yes - wastegate stays clamped longer, turbo spools up quicker, and boost
get developed at lower RPM/load.

[Here's what I'm more fuzzy about:  To get more boost you'll need a
different modded ECU (IA the only one?) and
spring to get to "Stage II" which is about 2.0 bar.]

No - you don't need a special ECU just chip yours.

[Is it possible to modify an already modified QLCC ECU for the 2.0 bar?]

Yes -  If you have a means of forcing the wastegate to stay clamped for
over 1.8 bar.  You can just augment the chipped ECU with the resistor mod.
 A value of around 4k is good, but you will want to be able to adjust this
while you dial in the desired boost.  So a variable resistor makes sense.

[ Is the only difference in the "Stage I" and "Stage II" ECU the pressure
transducer (PT)? I remember reading
about pneumatic setups that are used to control boost...are these used to
get more than 1.8 bar when using an ECU with the QLCC code?]

Please define Stage I, Stage II, etc.  I've heard this termnology thrown
around alot, but what does it really mean?

Yes, the Pneumatic control works well.  Basically a pressure regulator
which supplants using the frequency valve for wastegate control.  You can
dial in as much boost as you like until the engine detonates into oblivion.
 I do it, but warn a caution, things can start to blow quickly if you turn
that know too far.

[I'm sure I'll be plenty pleased with the 1.8 bar....but I also know I'll
want more. So, where do you go after the 1.8 bar mods?  Is a 2.0 bar spring
usable with a QLCC modded ECU?]

Yep, you'll like 1.8 bar.  start slowly and work your way from there.  I
think the next best thing to add is the bypass valve setup - not more
overall boost or horsepower, but will add performance and safety.

Adding fuel is the next best thing.  As Javad will say - go with EFI, but
not all of us want to completely rip out the CIS system.

[I know you veterans have been through these questions a thousand
times...sorry. :)]
'86 5ktq]

Yeh - need to do a FAQ on this...Will try to do this shortly, in between
tasks, but looks like I have some meat right above.


and my writup on this...

'87 5000 tqa - Engine rebuilt incl. following -
	T03/K26 hybrid turbo.
	Elgin 260i254e cam
	adjustable cam sprocket -  currently set for 0
	new valve seals, lifters & techtonics springs
	new piston rings, connecting rod and main bearings, all new seals.
	2-Piece Exhaust manifold, highflow cat and 2.5" Stebro exhaust.
	All visible casting flash removed from components.
	Mild port and polish to head and manifolds with ports matched.
	Bypass valve located in intercooler where untapped hole was with bypass
	flow directed toward turbo
	Supplimentary fuel injector installed in intercooler (but not connected to
	fuel or 034EFI yet) - injector is inline just prior to throttle body hose.
 Plan to do this soon!
	200 Flywheel, Clutch and Pressure plate, slave cyl.
	QLCC chip with variable resistor modded ECU, Schrapnel Knob + 2 bar SJM
	spring for control.

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