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Craig 930 RS Craig 930 RS is offline
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Craig 930 RS's Avatar
Join Date: Sep 2003
Location: Kirkland, WA
Posts: 10,196
A shop in my region has done a bunch of EFI conversions, at various levels, and tested the changes at various stages.

Data points you may find interesting:

EFI itself, with NOTHING else changed at all on a stock motor with perfectly running STOCK CIS = 20-25 hp
Carrera manifold on the above change = 25 hp

What do these mean? Not much. EFI simply allows everything to be optimized.

It is very difficult - almost impossible - to isolate the changes as shown above, as many other factors come into play:
A Carrera manifold - it really needs a decent turbo/airflow - not the stock qty - to push the air through the equal & larger runners.
This above setup was not 'CIS optimized', either.
A simple before/after conversion is nearly impossible, as much as we'd like to have that happen.
This comes from the workshop that has done a bunch of these.
An 'apples to apples' change is nearly impossible as one affects the other.

Mark, your car may/may not have an excess midrange fuel problem - time to test and not guess:

1) CIS goes full rich at a low WUR threshold - about 3 PSI of boost.
This means full stock fuel dump at that point!
1) You do not have the fuel head. The addition will definitely cause a severe midrange richness to occurr - I guarantee it.
Then you will require the RPM switch.
2) You are using a setup which has increased air delivery to the engine - and you have done nothing for fuel.
3) Brian Leask would recommend the adjustable WUR.
The adj. WUR delays full stock fuel dump initially at about 7 or 8 PSI - a great start for getting rid of the midrange richness problem!

As I indicated above, the fuel head isn't always necessary:
1) See what the AFRs are now
2) Then with the adj WUR
3) Then make the decision on the fuel head.

My car with stock WUR, lightly modified fuel head (for travel only, not slit enlargement), B&B header, K27 HF, twin plug, SC heads - ran with no richness problem in the midrange - low to mid 12s from about 3k all the way to almost 6k --- then it ran out of fuel.

Get yours tested first.

Brian sends the WUR semi pre-tuned for your application to help you get started.
It isn't too difficult to adjust and tune, it really isn't.
Dyno time and/or data logging is a must.
- Craig 3.4L, SC heads, 964 cams, B&B headers, K27 HF ZC turbo, Ruf IC. WUR & RPM switch, IA fuel head, Zork, G50/50 5 speed. 438 RWHP / 413 RWTQ -
"930 is the wild slut you sleep with who tries to kill you every time you "get it on" - Quote by Gabe
Movie: 930 on the dyno

Last edited by Craig 930 RS; 03-01-2007 at 07:02 AM..
Old 03-01-2007, 06:56 AM
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