how are you guys tunning your ls v-tec motors? what are the best air/fuel ratios for these set-ups? any info would be helpful. thanks

 

went to a tuner with an enginemanagement like hondata s300. But my air fuel was about 12.8 to 13.1 across the board.

 

It really depends on the brand and accuracy of your "wide band" and the location of where the sensor is. Tailpipe, end of header, in a primary. These will all give different results and numbers.

 

DonF, have you found any general "rules of thumb" for A/F and timing for engines with different geometry? Ex, do oversquare engines typically want something diff than undersquare, what do short rod engines want thats different from long rod?

This could turn out to be an informative thread after all.

 

The only "rule of thumb" I can give is that the richest point "lowest A/F number" is at peak TQ, then the number should rise. After that we are getting into fuel requirement for the engine. Specific gravity, burn rates, BTU's, octane, etc. VP c12, c16, Sunoco Blue, pump gas would all have different numbers. The other rule of thumb, if you have more compression than your fuel likes, run that boy rich, like most on here have to do.
EGT's actually tell you what is going on, but a cheap "wide band" is a good crutch and get you to "good" numbers.