Thread: MFI in a 930
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911st 911st is offline
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Join Date: Jan 2004
Location: Sacramento
Posts: 7,269
If one could design a flat TQ band under boost through careful design of cam turbo and maybe programmable boost by rpm it would make dialing in the MFI easer.

MFI is mostly correlated to TQ. If the air flow is stable with each stroke then the fuel need per stroke is stable and adapting the Space cam is easer. One might even be able to set up the pump so it dose not use a boost enrichment pot of one is ok w a simpler fuel curve that matches throttle angle more than load.

Another think to look at is intercooer efficiency and gross boost level. If one can keep the charge are temp down where the AFR can be set near 12/1 and allow the car to run safely, the car will still run off boost ok at those levels. If we need to go in the low 11's keep things cool it would be more difficult. It should not be hard to get proper AFR's at low throttle angle & curse rpm.

I think a 2.4T pump could be set up to work well by modifying the space cam at WOT at rpm. I have marked the space cam with a felt tip pen, driven at the rpm I wanted more fuel at and used a hand grinder and flat file to increase the fuel in that area using trial and error. One could use set of caliper and if you want 10% more fuel, cut the space cam 10% in that area.

Not sure what the gross fuel delivery limit if a 2.2/2.4 MFI pump is. It might require larger pistons at some point if going much over 300hp. I believe some have put them on race 3.6's so it might not be an issue.
Old 12-22-2009, 08:28 AM
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