For the sake of fuel economy, running an open loop program, how far above 14.7 is it safe to go. I know this may hard to answer as the load of teh engine and whatnot probably have an effect, but I figure that 14.7 was used for emmissions purposes so it may be safe to go further under 60kpa manifold pressure in other words not a lot of load, or would the load matter. I figured at WOT or near 100 kpa there would be more heat, or is it the same temp just less gases that are that temp at lower loads?? I am trying to make use of my low budget and tunercat so any help can be appreciated

 

I think I remember seeing before that some of the guys that do chips for GN's have edited the code so that they can command ~16:1 a/f ratio for cruise.
You are using a wideband for this a/f tuning correct?

 

many people have seen 28 mpg on the highway with your mods.. how much better can it get??

to answer your question.. unless you put the car in open loop all the time thered be no way of keeping a 16:1 AFR during cruise. This means youll need a wideband O2 sensor to keep track of the AFR which are about $120-$150 for a cheap Honda sensor. I think some kits run in the $250-$300 range.

 

Yes I was planning on getting a wideband maybe for my birthday as a gift, the ones ive seen are $350. Yes I get 28 on the highway but I almost never drive on the highway, in the city I get maybe 14mpg. Yes I was planning on making an open loop tune as well Thanks for the input so far keep it coming