KH wg spring in mc turbo results

[Sachelle Babbar <sbabbar@iris.nyit.edu>]

While I was at it, I replaced the stock mc wastegate spring with the kh
turbo sprin from it old wastegate. An upgrade was made- the later
wastegates use a different spring perch up top, a fixed, non bushing type.
The kh had a removeable, rotating perch of a larger diameter. The mc
spring is shorter, smaller in diameter. The conversion required the use of
the kh wastegate cap, no biggie. The lower perch on the diaphragm is for a
smaller spring, so there is some play between it and the larger kh spring.
Under standard preload, is not a factor.

What I didn't like about the mc: The spring allows for poor bottom end.
This comparison is based on the more torquey kh. The old setup was higher
static compression, factory boost at 1.5 bar. My setup was 7 .4mm shims on
the spring, bringing boost to 1.69 bar (sometimes 1.7 would be indicated
under cold conditions)+ the pneumatic cockpit wastegate controller
bringing final boost to 2.0.

What I liked about the kh: torquey, attributable to the higher compression
and the retarded timing I found out about later. Give smooth throttle on
highway, not enough to induce slushbox kickdown, but top gear
accelerating. Torquey down low, then boost hits and a gradual "push" for
lack of a better term into the seat. Felt great on my bad back. The car
wasn't accelerating like mad, though. 
With the wg controller, I could dial up boost in .1 bar increments with a
great range of adjustment. Boost curve could be adjusted, too. 

The mc never had the seat of the pants and stock, was never a faster
feeling car, even though it is and has more factory power. Off idle torque
sucked (by comparison, no flames, please). With the wg controller, only on
the mc (no spring shims) power would go from next to nothing to **sudden**
explosion of power. Essentially useless power because it was going up at
such a high rate over a large power gradient. Next to nothing to a hell of
a lot in almost no time. Wg controller: on or off. No in between. It was
either 1.35 or 2.0 bar. The only adjustment to have been made was the
boost curve could be increased, but peak was the same, only it arrived
earlier.

KH spring + MC engine. Wonderful match. There is more down low torque and
the power is useable. Stock, a mild in crease in boost, maybe .1-.2. Power
arrives earlier, but more progressive and incredibly controllable (I have
a fwd 5 speed). It's overall a torquier feeling engine and I actually have
what feels like power in the wg controller closed position. I've restored
the adjustability in the boost increase; I haven't seen 1.7 bar since my
old kh. Just goes straight from 1.5-1.9. I can execute many maneuvers that
I haven't been able to since my kh.

Conversely, I feel that the lighter mc spring in the kh + the wastegate
controller would be a wonderful combination due to the engine's better off
Idle torque.

Timing belt time soon and I may retard or advance timing based on what I
want. I feel that I want more top end. My kh had *quite* a bit more top
end (feel). I'm really just looking to duplicate the feel of the now
deceased kh. The current mc car is no longer an attraction to my friends
because that feel is no longer there.
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*Steve                                             Sachelle Babbar
*'87  5000CS Turbo 5spd 1.3-2.0 bar             <SBABBAR@IRIS.NYIT.EDU>
*Cockpit adjustable wastegate, AudiSport badge
*
*Disclaimer:"Any information contained herein is based purely on my own
*personal experience and may not necessarily reflect yours. Use caution as
*your results may vary from mine."
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