When I tuned my car I shot for 13.0ish a/f from 4000 to 8500 rpm. Now i was thinking that if the car is moving, more air should be getting to the filter therefore maybe leaning it out. Could this be why you here people saying that they tuned the car to perfection on the dyno, but ran slower times at the strip? I have a open loop ecu so I think it runs the same map all the time. What do you guys think?

 

Well I just found out that the general rule of thumb on a/f ratios is that you could lean out up to 5 points from the dyno to the street. In case anyone gives a f00k.

 

The dyno should have large fans, so I can't see how there would be a great difference in the amount of air getting to the filter.

 

Icebox is basically ram air, so at high speeds (which I don't think a fan can duplicate) would theoretically lean out some.

 

I've read (in the AEM EMS manual) that you should tune on the dyno with race gas and then you'll be safe on the street with pump gas. A dyno puts more load on the engine than the street does. Judging from that statement, I don't see how you could be leaner on the street.

 

I think it very depeneded on the intake system and the dyno environment. So I think it is very difficult to estimate the actual difference between the dyno and real time driving condition. I would just tune to its best on the dyno and wouldn't worry about it.

 

13 sounds kind of lean for that area. You might wanna shoot for 12.9-12.5.