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Re: Frontal area air flow

Posted: Fri Dec 30, 2016 9:03 am
by BOOT
Air dams that are under the bumper create more down force than reduce drag, straight down from the tip is better for reducing drag as said.

The Porsche adjustable front spoiler has three modes
-street, high for curbs n speed bumps or w/e
-sport, low for aero n downforce
-top end/mph, low sides & raised center

Sure funny cars are the whole front but they also got nothing under and the body really and it comes off so it's the only practical option. And handling cars want downforce. I looked into this awhile back for drag racing and my conclusion was in front of the forward tires are important for normal cars straight-line aero and it only really starts to noticeably help somewhere above 110mph. On a drag car the front tires are skinny but any suspension that hangs is also a concern. Rear tires stuff has slowed down a lot unless they stick out on the sides. I'd try a low front tip air dam or a sides only and belly pan.


Remove your side mirrors, antenna or anything that sticks out.

Re: Frontal area air flow

Posted: Fri Dec 30, 2016 9:37 am
by LaVelle
I'm not sure what you mean by straight down from the tip.
For air dam/chin spoiler I was going to make something along this line for under the bumper.
spoiler_rev9-iso_1.jpg

Re: Frontal area air flow

Posted: Fri Dec 30, 2016 8:40 pm
by BOOT
pic 5 n 6 from Greenlight's link

https://hanchagroup.wordpress.com/2013/ ... n-is-best/

edit: The reason is to divert air around and not under. Unless you have a really flat floor like I bet the Porsche does and a lot of new fancy sports cars do, then it might be not worth adding the frontal area except around the tires n suspension.

Re: Frontal area air flow

Posted: Sat Dec 31, 2016 4:58 am
by LaVelle
I see what you mean by from the tip now.
I'm going more #3.
If it slows the car down it will just get taken off.

Re: Frontal area air flow

Posted: Sat Dec 31, 2016 4:24 pm
by ijames
A forum you can skim for ideas is at: http://ecomodder.com/forum/aerodynamics.html. Look at the stickies at the top first. If you can scrounge some conveyor belt material it makes good airdams, stiff enough not to deflect from wind but survives a lot of road debris attacks. If you want it on all the time on the street leave maybe 3" of gap or more. Some have used https://www.amazon.com/gp/product/B006K ... UTF8&psc=1 but I think that is a little thin. Others have used lawn edging from homedepot or lowes.

Re: Frontal area air flow

Posted: Thu Jan 12, 2017 8:35 pm
by MadBill
I've done aerodynamic mods on a number of street and race cars and the results can be quite gratifying. BUT even for a really fast drag car, the fact that they spend so little time at speed means the effect will usually be very small. If you can access a good quarter mile predictive program, the effect on E.T. of say a 0.02 reduction Cd could be modeled.
Bottom line, a simple airdam should help a little but doesn't merit expending too much effort.