At what AFR will detonation start occuring? I had a AFR of 14.1 the other day. I was datalogging on the UTEC at the time and had no knock. Just curious.

 

Detonation can happen at a wide range of A/F ratios. There is no one magic number.

 

Depends on peak cylinder pressures, temps, octane, etc. Anyway if you're at vacuum, 14.7 is perfectly fine.

 

So long as the 14.1 was not while boosting, you're ok...

 

i think its your wideband...


14 to 1 would knock pretty bad under high boost levels on pump gas...

 

Well put; AFR to induce knock depends primarily on engine load, and engine RPM.

 

if you were under load and had a 14:1 afr you'd be in trouble..
If you were coasting/cruising not under load you're ok

Problems come in when you're under load and the timing is getting advanced with that afr.....

 

Larry,

I would suggest putting the car on a dyno and putting a tail pipe sniffer wideband in there. then, compare your wideband to the dyno wideband to see the difference.

the other item would be to install an o2 bung in the other downpipe to check and see if you you have a difference from one side to the other.

 

yeah just call to schedule some dyno time if you need it. thanks!!

 

Not an expert, but I see AFR's like that in vacuum, definetly not in boost. You should be fine.

 

The AFR was at WOT at 6500 RPM. Still wasn't detonating. The thing about my wideband being innacurate is that it is dead accurate when off the UTEC and on the OEM computer. 14.2-14.7 when cruising around. So it is accurate then.

I am trying to get an appointment to get on a load based dyno and check the AFR against my Innovate.

Thanks Jeremy. If I need some tuning I will only let you touch it. No Doubt. Then I will also have AFR's from another dyno to check agaisnt yours as well.