If a car has a dynotune while running thru an exhaust system, is it OK to run open headers at the track or would it run to lean? Anybody ever try this and do you have any results you could share?

 

i tried this with long tubes and found the car runing rich because the o2s are to close to end of the colector and fresh air from the outside will swirl in and and hit the o2s and give you a false lean a the pcm will start dumping fuel and you will run exremly rich.

just put a 12" peice of pipe on each colector and that will solve your problem.