cutting holes in your rear bumper

[almightybmw]

mmmmm. Grand Prix's have parachutes for rear bumbers. My SE has about 8-9" of just plastic hanging out, that can catch air off the rear subframe. The GT and GTP have over a foot of plastic that hangs down. There is nothing to stop air from trapping, and those that do race their GTP's have shown a few tenths or more dropped in the 1/4 by sealing it up.

I wouldn't cut holes, I'd seal it. Ya spent all that money on the car, why butcher it?

[JasonG]

Do a search here for belly pan. I agree it will give much better results, just watch the muffler.
The balance is that the underside of a car is very dirty aero wise. The gains are small but every bit adds up.

[tasdrouille]

I'd say those holes are just to get people talking about your car instead of just another reasonably fast car. I'd seal it from underneath.

[Christ]

Why butcher it? Because it "looks cool"... like body kits.

[k.civic.f4i]

dont do it man. youre better off with a partial pan back there. plus im sure you dont want every honda ricer/tuners out there trying to race you at every light (hate that). for some reason some of them come to think that the grill block has something to do with racing(it actually might help).

[thatguitarguy]

Originally Posted by Frank Lee

Now you have me curious: How does more rubber on the ground in the rear make this car quicker???

Maybe some fat tires would block off all the air that's filling that bumper???

[Ryland]

If you really want to cut part of your bumper then go lower, those holes are to high in my mind, trim the lower edge that hangs down and catches the air, then add some stream lining ahead of it.

[MadisonMPG]

Yes, the holes work. *no sources, but i've seen it happen*

Guy gained about .2 on his 1/4, with a faster MPH.

[Tygen1]

Originally Posted by MadisonMPG

Yes, the holes work. *no sources, but i've seen it happen*

Guy gained about .2 on his 1/4, with a faster MPH.

Sorry, I'm not buying it. I have a slow car, and just a little wheel spin can be a .2 difference. You just can't use a dragstrip to measure aero changes. I could probably list about one hundred things that could happen between two back to back runs that could alter the ET. Have this dude tape up them holes then do some coast down testing, A-B-A, then you can make a believer out of me.

[Sorrow Six Star]

Originally Posted by MadisonMPG

Yes, the holes work. *no sources, but i've seen it happen*

Guy gained about .2 on his 1/4, with a faster MPH.

yeah I agree but that's a way to do it and have noticed like someone else said.

the holes will help and get you attention
a belly pan will help more and not get you attention.



no one will blame you if you'd like to have speed holes.
"we" will respect sealing the sir out more than we will the holes.
the rest of the world might appreciate the "holes" more.