Whats the best AFR for power on these motors? I had a 250 and when dynoed it produced most power at high 13 (13.5+) to low 14:1 ratios.

I have an auto tune set up and wondering what the best ratio for power is

You may want to read this thread. https://www.ninjette.org/forums/showpost.php?p=266618&postcount=17
https://www.ninjette.org/forums/showpost.php?p=267279&postcount=28

As a rule of thumb, peak torque is typically from 0.87 to 0.90 lambda. When talking in 100% gasoline speak where Stoich is 14.7:1, peak torque is usually 12.8 to 13.2:1. This of course depends on the combustion chamber shape, flame propagation speed, BSFC, VE, and a whole bunch of other factors.

Start with a 0.88 lambda target, and feel free to twiddle it a bit on the dyno to see where the sweet spot is at each programmable RPM cell in your Dynojet interface. Since you're tuning a naturally aspirated engine, it's unlikely you'll need to run any richer than 0.82 lambda or 12.0:1 AFR unless you're getting knock.

Good luck!

You may want to read this thread. https://www.ninjette.org/forums/showpost.php?p=266618&postcount=17
https://www.ninjette.org/forums/showpost.php?p=267279&postcount=28

Yes I was looking more for real world experience such as the second post

Yes I was looking more for real world experience such as the second post

I just linked you to a couple of good single post. Here's the whole thing. Maybe it might be enough real world data for you.

https://www.ninjette.org/forums/showthread.php?p=266618#post266618

Remember to install your wideband sensor upstream of the catalytic converter if you're still running one or you won't get accurate O2 readings.

o2 is only half of the tuning(not really other factors involved), you need to look at changing ignition timing aswell.

If the stock ECU can change the pre-programmed timing settings, if not have to look into ignition control.

Changing "o2" cleans up the hills and valley's and corrects the AFR, and a power increase or loss could occur.