The max the AFC can lean out is 50%. The AFC tricks the ECU into thinking it still on 450cc injectors. So the Largent injectors correctable by a S-AFC is 900cc Theoredically.

Sorry this is a really late reply...

Something everyone is forgetting is that the reason that 650's are considered the limit with AFC is becasuse of TIMING, not fuel. The more you lie to your ECU with the AFC, the further off your timing gets. That's why people say to get a modified chip. When you lean out the AFC your timing gets more advanced. At full boost with too much correction you will have hugely advanced timing.

One thing you can do (if you own a 1g) is upgrade to the 2g MAF. Doing that requires enriching on the AFC, which will bring timing closer to where it should be. Or, you can hack the maf you have. Take out the lower honey comb. Un screw the maf adjuster. Basically you want to do whatever you can to allow more un-metered air around the maf so you can offset the needed adjustment for the injectors. For more info on that go and .

I'd recommend reading these links:
http://www.dsmtuners.com/forums/article ... guide.html
http://www.roadraceengineering.com/newafc.htm

or the other fix is to just run as much boost as possible to get the air flow up and get onto a better timing map

I'll trade you your 680's for my RC550's?

thats a huge mistake............ 550's for 660's. That problem only applies to 1G cars. 2G's only get 16 degrees of timing anyway so its not a problem. Run the 650, 660, 0r 680 and have it tuned on a dyno with a wide band and logger. You'll be fine.