what is the proper air fuel ratio guess for a b20 vtec 16.5?

 

14.7 for any engine

(I think 14.7 is stoich...not 100%)

 

14.7:1 is stoich but NOT what you want for power... We normally shoot for ~13.0-13.5:1 on naturally aspirated motors... 16.5:1 is extremely lean and I sure hope you're not currently running your motor at that... Bottom end partial throttle is fine at around 14.7:1... Just my $0.02, Peace

 

mine fluctuates from 12 to 10 damn is this bad and what exactly can i do to change it?

 

Is this a wideband that you are running on your car or is it just some cheap A/F meter? If it's a wideband it's most likely accurate and your car is running rich, just remember that being rich is better than being too lean but you're still losing power... On a boosted motor I normally tune for ~12.0-12.5:1 so you can see that if you're truely down in the 10's that is considerably rich... If you are getting these numbers off a cheap A/F gauge that reads the stock oxygen sensors output voltage I really wouldn't trust it... Sorry I can't help ya more, Latez

EDIT: Also are you running aftermarket injectors? Anything for tuning? (Hondata, VAFC, etc.) I would also recommend pulling your plugs, you'll know right away if you're too rich/lean, etc. If you have a digi cam pull them, post them, and I'll check them out...

 

bump good question

 

There is no "perfect" number. Tune the motor to make power and bump it down a tad. Most turbo apps like the 12.5:1 +/- .5. N/A usually likes around the 13.5-14:1 area.