What ( roughly ) air/fuel for most power ?

[AJ4]

As title suggests, am setting up my PFC soon with a wideband O2 sensor, need a target AF ratio to aim for.

Anyone know what is a good starting point for the SR20DET ? 12.5:1 ? 13:1 ?

Just need a rough starting figure, will all be fine tuned in the end.

Cheers

Ross.

 

[Sirnixalot]

13:1 is way too lean for a boosted motor.

stick with 12-12.5 at the most.

 

[ashills]

11.5 for sr20

 

[Fast Guy]

I saw something about 5%co being best for power, but I don't know what afr that equates too. :?

 

[GINGA]

12.5 is best for power but you risk melting pistons etc at that better to aim for around the 11-11.5 mark to give yourself alittle bit of safety

 

[GINGA]

Also buy the best wideband you can afford and don't leave it fitted just use it for tuning only as the sensors aren't supposed to last that long
I have the greddy unit that although it goes from afr 8-16 I don't think its a true wideband and its fairly old and I don't trust it at all relying more on the egt gauge to let me know its lean than the afr gauge :roll:

 

[GINGA]

Goes for the hatrick :lol:
Ross with the fc datalogic can it do you a line graph of say rpm against knock so you could do a run then look at what the det levels were throughout the rpm range used so you could fine tune the timing etc :?:

 

[Nad]

Most Widebands last about 300miles.

Nad

 

[andygtir]

abbey mapped mine to 11.5 - 12.0

 

[323GT-R]

Most Widebands last about 300miles.

Nad

:shock: Mine must be screwed by now then... :lol:

It depends what fuel you're using and what EGT temps you get, don't forget some Honda's have widebands fitted as standard, so they can't be all that bad

 

[ashills]

ive got the latest bosch one which is longest lasting u can get
the older style ones are something like 200 hours i think
mines plugged in all time and seems fine and there cheaper than a gtir lambda lol