soldave

iTrader: (1)

Just got myself an AEM wideband and have picked up a 5-**** "older than time itself" SAFC and plan to do a a bit of very basic and mild fuel tuning on my 1991 S5 Tii FC. Don't have any major engine mods; in fact I've just got the emissions stuff removed, full intake & exhaust, stock & freshly cleaned injectors and a full tune-up. Have also done a complete rewire of the fuel pump to a straight relay and removed the variable resistor so I know it's going to be running rich.

The 5-**** SAFC just has 5 rpm levels at which to adjust the fuelling (800, 2400, 4000, 5600 and 7200rpm), and can adjust up to 30% either way of stock. Am probably going to do my tuning for 4000, 5600 and 7200 at WOT and will probably take a reading for 2400 at WOT and also when cruising too. Was wondering what I should be aiming for in terms of a little leaner but still safe AFRs. Am not going to be boosting much above 10psi (12psi would be an absolute and unlikely maximum).

Idle & WOT AFR thoughts would be appreciated

Pullout1979

I have the exact same safc 5 *** on my 88. It was put in by the previous owner and I'm somewhat lost with it. Any clarification on the different settings on it would be great(tips for performance etc.)

Osirus9

iTrader: (10)

safe AFRs at WOT on a turbo are between 10 and 12. a good cruising AFR is 13. These AFRs are conservative, but with a setup like that you don't want to get anywhere near the hairy edge of the fuel curve.