Was wondering what everyones air fuel ratios are in boost and what is considered safe. I have a kraftwerks kit pushing 460whp making 16psi. My afr in the summer time has gone as low as 10.4 in boost. And recently ive added a trackforged evacpipe and the temps have gotten in the 60's so im seeing 11-11.2 afr.

 

I generally have mine tuned between 11.8-12.0.

Anywhere around 11.5-11.7 is normal... IMHO anything less than 11.5 is too rich. The throttle response tends to be better on my car around 11.8-12.0

The added extra fuel tends to be a bit safer due to it running a smidge cooler. If you run your car hard often you may want it a bit on the richer side.

 

Out of curiosity... what are you using to read that 10.4?

 

x2 on this post.

To OP; 10.4 is absurd. Waste of fuel and leaving power on the table and could actually be washing your cylinders if its lower in the rpm range. Hows your oil look and smell? Running that way for not too long will also pre maturely foul out the 02 sensors, and develop deposits on the spark plugs, valves and exhaust ports, which isn't what you want if your trying to keep your engine clean and running top efficient shape. Eventually as the deposits get more caked on, you will develop hot spots and engine will become detonation prone, which is really what you don't want. Its a downward spiral. You want a safe and efficiency fuel tune, and a timing advance to coincide with that philosophy, efficiency and cool running with enough headroom to operate safely in more severe hot conditions. Mid 11's is as rich as anyone would need in normal sercomstances, and upper 11's to low 12's is a good common target in most cases.

 

when I was Superchaged I ran leaner in the lower rpms where boost was minimal, because there is a much bigger headroom there and the motor response well. I ran upper 12's at WOT up to about 4.5-5k rpm where I started enriching past that some to mid 12's and then finally to upper 11's by redline at 18 psi.

 

Using aem uego wideband. Was tuned by jeff evans. It was 10.4 near redline.leaner in the beginning.been running leaner now that the temps are cooler.

 

Think jeff was tryna tune the power down a bit and richened the top end.

 

Ok...I just wanted to be sure that value wasn't being read off the OEM O2 sensor...it's inaccurate that low.

 

Wonder why jeff tunes so rich. But just wanna make sure im oky

 

Did you ask him? Does seem awfully rich..