Advice for new 90tq needed

[ed armstrong]

--- Ben Swann <bswann at worldnet.att.net> wrote:
> [Hi Jim, Thanks for responding.
>
> I do have a stock MC-1 intake manifold and it has a
> little 2" piece of rubber hose between the head and
> intake manifold. That should be OK right ?
>
> There is another  connection right next to the TB
> that
> I wasn't sure about (What is this for ?). So I just
> routed it to intake vacuum.
>
> A third connection coming off the hot side of the
> turbo just before the intercooler inlet was also
> routed to vacuum (could this be a problem ?).
>
> I do have a bypass valve (brand new) in blow off
> mode
> attached to a intercooler outlet (intercooler from a
> KH turbo) but I don't think its leaking.
>
> Wouldn't a leak send me to the lean side anyway ?
>
> =====
> -ed]
>
> Ed,
>
> The throttle body port should be going to the
> charcoal canister shutoff
> valve - I think routing it to intake vacuum would
> throw things off, since
> it is different than the manifold vacuum depending
> upon throttle position.
>  At least block it off and get it out of the picture
> for now to rule it
> out.
>
> Mixture tweeking  - counter-clockewise to lean,
> clockwise to enrich.
>
> I made the mistake of plumbing the bypass control
> port to the same throttle
> body port.  Make sure you don't have it this way, or
> bypass will not work
> correctly and you risk overspinning the turbo.
>
> I'm not sure exactly the reasoning engineers decided
> to put a port just
> before the turbo (cold side), but that would be a
> different pressure
> (vacuum all of the time), so don't route to manifold
> vacuum.
>
> I have a modified vacuum diagram I've been meaning
> to post on my website,
> which may help.  I uploaded the file.  It is:
>
http://www.homestead.com/ben_swann/files/Vacuum5kt.jpg
>
> Ben
> '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.
> 	200 Flywheel, Clutch and Pressure plate, slave cyl.
> 	QLCC chip with variable resistor modded ECU,
> Schrapnel Knob + 2 bar SJM
> 	spring for control - set for 16 PSI until fuel
> injector is enabled.
>

Thanks Ben and Jim for the ideas. I think I will start
to pinch off some of the vacuum connections I talked
about and check the blow off valve and see what gives.
The vacuum diagram is a big help.

I was wrong about the hot-side turbo vacuum
connection. Its the cold side of course. I'm having
problems visualizing everything sittin at my desk!


=====
-ed

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