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Forum nameTurbo/Nitrous Tech
Topic subjectsfmu question
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=103835
103835, sfmu question
Posted by 97esiboosted, Jun-21-08 02:40 PM
i got it and running with 30lb injectors large disk and silver spring idle fp 20lb Static fuel pressure 40. but i can not get the sfmu above 60lb at 9 lb of boost. and its running a little lean under boost(13.8-14.7 afr).

edit:i have the static screw all the way down(with out bottoming out).
103836, RE: sfmu question
Posted by cs82685, Jun-21-08 02:54 PM
Originally posted by 97esiboosted
i got it and running with 30lb injectors large disk and silver spring idle fp 20lb Static fuel pressure 40. but i can not get the sfmu above 60lb at 9 lb of boost. and its running a little lean under boost(13.8-14.7 afr).


I followed the same for my setup which is identical and I had the same problems. I haven't really had time to mess with it, but I just ended up raising idle fuel pressure until it no longer leaned out under boost (I want to say somewhere around 30-35psi). For the most part, the stock ECU seems to keep the a/f's around 14.7 when cruising although I have noticed sometimes just a slight change in pressure with the right foot while cruising down the highway and it will richen up again without me being in boost. It eventually settles back down but I haven't even been able to run a tank of gas yet to see if it's killing my mileage or not. Hopefully some others will have suggestions to help you (and me) with this problem.
103838, RE: sfmu question
Posted by SilvrEclips, Jun-23-08 06:10 AM
I use to run my SFMU at 20-25psi idle and static to 33psi or so. With the largest disc and black spring I was about 11.5 a/f. There were a few rich and lean spots I had to take out but the base tune was good. I would check to make sure the SFMU isin't leaking your boost pressure out the chamber. Blow in the hose or pressurize it with an air compressor and test it at 9psi to see if its leaking.
103839, RE: sfmu question
Posted by 97esiboosted, Jun-23-08 11:47 AM
i think i need the black spring