AFR question...

[6o4turbo]

Right now for general cruising my AFR's bounce between 15.4 - 17.9, is that too lean that its going to cause detonation at cruising. Or is this totally safe? My idle is sitting right at 14.7 - 15.3 Only running about 5 psi at about 20 - 30% throttle when I'm bouncing in the 15 - 18 range.

Any input would be appreciated.

Thanks.

 

[MK3Brent]

Those are normal cruise AFR's.

 

[lagged]

i cant give you any help, sorry for that. but i would like to ask if you have an EGT gauge and if so, where is the probe and what kind of readings are you seeing at each corresponding AFR ratio and RPM, boost level etc..

 

[6o4turbo]

So you guys are saying that when at a steady cruise, let's say at 2200 RPM, the AFR's fluctuating from 14.x to 17.x is normal?

I was under the impression that the AFR's should be steadier than that. Closer to the 14.7 range, back and forth.

I haven't even gone into the high throttle settings on my SAFC II yet, as I haven't gone over 50% throttle. So were talking these numbers are for all in the 10% - 50% throttle range.

If I lean out to let's say, 17.x when I'm at 3500 RPM and running 10 PSI at 30% throttle am I going to cause damage? Or can I get away with higher AFR's because I'm not going WOT?

I've got my idle fuel pressure set at 30 PSI.

If this isn't enough info on the problem let me know.

Any help I can get would be greatly appreciated here...

 

[SPD TRP]

Right now for general cruising my AFR's bounce between 15.4 - 17.9, is that too lean that its going to cause detonation at cruising. Or is this totally safe? My idle is sitting right at 14.7 - 15.3 Only running about 5 psi at about 20 - 30% throttle when I'm bouncing in the 15 - 18 range.

Any input would be appreciated.

Thanks.

Are you reading those afr's with a wide band or the narrow band bouncy afr gauge?



If with a reputable wide band, 17.9 is way lean at cruise imho. Mine at cruise using the ecu and not the pro bounce from 14.5 to about 14.9, when I say bounce I mean they bounce but always in that range.

Wayne

 

[6o4turbo]

Are you reading those afr's with a wide band or the narrow band bouncy afr gauge?



If with a reputable wide band, 17.9 is way lean at cruise imho. Mine at cruise using the ecu and not the pro bounce from 14.5 to about 14.9, when I say bounce I mean they bounce but always in that range.

Wayne

I'm using a AEM Wideband...

 

[Red Dragon]

Mine constantly bounces at cruise, using AEM as well. At idle and cruise it bounces from 14.7-15.5-ish. Hit the throttle and down it goes and locks in around 10-ish.