Blow-off valve

[dmaxstang]

OK, stupid question but i was blown away by a late model firechicken today and when stopped, he revved the motor and i have not heard a car come back down from high RPMs that quickly and almost sounded like a blow off valve was with it. What could it have been and would that allow the stang to rev quickly up and down like that, almost like immediate full throttle not a steady up rise in the rev??????

 

[bigcat]

OK, stupid question but i was blown away by a late model firechicken today and when stopped, he revved the motor and i have not heard a car come back down from high RPMs that quickly and almost sounded like a blow off valve was with it. What could it have been and would that allow the stang to rev quickly up and down like that, almost like immediate full throttle not a steady up rise in the rev??????

dont rule out the posssibility of a turbo on the firechicken. i believe that a tune will help your throttle lag.