If you look beyond Porches, lots of people have found that Bosch built a lot of headroom into CIS. The commonly accepted figure for the Rabbit GTI is ~140 HP before you have fueling problems. The stock HP for that engine is 90.
Only person I know of who tried it with a 911 was "rdane" who got ~223hp to the wheels with a 3.4 with early CIS.
Details here Assuming ~15% driveline loss, that is around 250HP for an engine that came stock with ~180.
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Originally Posted by 911st
I suspect of 36mm port can support 250hp (my old 2.8 mfi), a 39mm should be able to support more than that.
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My 3.2 CIS kind of
falls on it's face up top, I expect the small ports are largely to blame. But they are 34mm, not 36.
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If we set our idle and cruse AFR near 14/1 and wish 13/1 for max TQ, we need more fuel. USA Porsche CIS cars do not have an enrichment function and can go to 17/1 AFR on first accel. This is part of the reason along with the low compression why CIS is not know for its throttle response.
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I don't think this is correct. I know the CIS-Lamda does, from the Lamda box, triggered by the full throttle switch. The CIS basic had enrichment through the WUR. The factory manual show 2 different control pressures, with and without vacuum. They system gets richer when manifold vacuum drops.
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Set CR to 10.5, lower control pressure with accel so the metering plate starts moving so we get in instant 13/1 AFR on top of twin plug ignition and it will wake CIS up.
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Twin plug is pretty much mandatory on that bore size.
Honestly, For the time and effort involved with building the Andial engine, unless you are doing it for a engineering exercise, save your time and money. Sell your engine and put the proceeds toward a 3.6.
Tom