Hondata

i would like to know what you guys consider "lean" to be. because you guys say that the 05/06 rsx-s with a race header and reflash will run lean. yet i remember doug telling me that you guys run your afr at 14 in you're k20 engines. so my question is, what is too lean?

This has been answered many times. Adding a race header to the reflash will make it run lean. It won't be any leaner than stock, but it still will be lean. If you want to find out how lean, you'll need to put the car on a dyno with wideband. We cannot guess what the exact lambda will be.

so then what air to fuel ratio would you consider to be "lean" some people think 13.5:1 is lean, others think 14:1 is lean, what do you consider lean?

I have heard that with a shorty header, you will not run lean. Is this true or false?

You'll run leaner the optimum in the mid range, but it probably is not going to be a problem. As always, a dyno will tell you.