Re: Schrappnell Knobben (R)eport

[Steve Manning <stephenm@ix.netcom.com>]

At 06:03 PM 9/11/97 -0700, you wrote:
>I bought an IA modified ECU for the ur-q, but was sent a stock urq WG 
>spring, meaning that I don't get much improvement.  Today at lunch I 
>was digging under the hood and got the bug to finally install the pres-
>sure regulator and connect it to the top of the WG.  I don't know where 
>most folks tap into manifold pressure ... I T-ed into the larger dia-
>meter line that bypasses the throttle body when the A/C compressor is 
>enabled, and chose the line that is attached before the throttle body.  
>I wanted to report my findings and see if I could get some feedback 
>from others out there that have installed the kit ...

I T-ed into one of the 3mm rubber hoses coming out of the back of the
intake manifold (BTW, car is a 1990 200tqw).

>Since I am still using the stock MP gauge I didn't want to get too 
>aggressive, so I adjusted the regulator to provide max MP of 2bar as 
>measured on the gauge.  It appears that the actual amount of pressure 
>applied to the top of the WG was 2 PSI to achieve this boost level.  
>I was wondering what sorts of boost levels others of you are running 
>with your S-Kn equipped engines, and what sort of pressure settings 
>these would imply on the pressure regulator.

I'm running an actual max 12psi (as measured by a gauge tapped into the
back of the manifold).  Schrappnell Knobben seems to provide a 5/8 ratio
(in other words, .5 bar on the stock dash gauge is actually about .8 bar
real boost).

>I currently have the 
>pressure regulator suspended in the hoses near the ignition coil ... 
>has anyone mounted their regulators somewhere in the engine compart-
>ment or cockpit?

I drilled a hole through the plug in the third outlet on the Knob, put a
bolt through it facing out, then bolted it neatly onto a bracket on the
firewall....looks clean and neat (it's a bit heavy to just hang on all
those hoses).  I avoided the cockpit mounting because of the tempation
factor.  By the way, it's a great 'valet' switch....a few turns under the
hood and max boost disappears into the toilet.

>Now that I've got the thing installed I'm going to be looking for a 
>one way valve that I can use to allow the pressure to be held on the 
>WG even after the boost has gone down, so that way I'll have the stif-
>fer effective spring before the boost comes back.  This was discussed 
>on the list sometime back, but I never heard if anyone actually did it.

Hmmm....I'd like to hear more about that too.

>I guess I'll need to do some timed runs to see how much performance 
>improvements that fraction of a bar provided, but it _seems_ small but 
>perceptable ... and it is fun ... :)

After spending months baselining the car back to stock (fixing hoses,
vacuum leaks, throttle switch, etc. etc), I was going 30-70 in third gear
in about 14 seconds.  Just adding the Samco turbo/intercooler hoses and the
Knob mod (set to about 12psi), I could do the same run in 9 seconds.  Works
for me!........SLM

>Steve Buchholz
>San Jose, CA (USA)


Steve Manning:  stephenm@ix.netcom.com
...Physical home: Metro D.C. area, USA
.....Virtual home:  http://www.stationwagon.com