Defrost on loss of power?

[lynnriderm6]

idk if anyone eles has felt this but i had the defrost on the other night and didnt feel anything in 1st gear but when i gave the car a good push in 2nd around 5400-5500 rpms felt like my car just died...i know how the car feels after 5800-6000 but it felt dif. almost like it was sputtering...with the defroster off it doesnt do that though..any ideas sorry for the run on sentence lol

[coyfish]

Well this car's powerband dies after 5600ish. When I had only a few bolt ons I didn't feel it but now with more mods (minus the AP) I felt it just die after 5700.

That and running the air unit will sacrifice a little power. Some people say its not much at all but I definately feel my car run slower with the air on.