On some nicely built drag Cars, why do they cut off that section of the back bumper? is it for clearance? better aerodynamics? I'm just wondering
Same for those "Holes" put in

 

yes AERO'S would be correct think of all the air being trapped up underneath it

 

Yep. its for wind drag. I call em speed holes. the back bumper can act as like a parachute effect.

 

Oh ok Cool Thanks! I always thought it was pointless, Now i'm going to do it on my DD single SLAM!! jk

 

it is.....unless youre car is going really fast.

although the civic vx's had a plastic underbody piece (diffuser) to cover up the hole in the bottom of the bumper so it wouldnt trap air in there.

 

 

rather then cut my bumper i simply went honda and ordered the VX diffuser and hardware. its a direct bolt on for all 92-95 hatches. my car only traps mid to high 130s, not sure if its helping me much at them speeds or not.

 

Mista Bone claimed 2-3 mph on a 13sec car from simply removing the bumper altogether.

 

weight reduction LOL

 

I was there a few years ago when he was experimenting with that. Never did here how it turned out though

 

will that VX plate fit a 4dr eg..no prolly but could it be modified easily?