Spoiler differences

[skirkland1980]

I'm trying to figure out why a drag race car uses a different rear wing than say a road or circle track car. What brought this to my attention was the Lexus ISF crash that happened recently which the car had a road course style air foil instead of the typical style wing in which is common for drag cars.

[skirkland1980]

https://m.youtube.com/?#/watch?v=Zxe_DqAkeAk here is the video and you can see the air foil which us not typical to drag cars. Just wondering if it played a role in the crash.

[skirkland1980]

Here is the type of rear wing you'll see on most serious drag cars.

[RebekahsZ]

I don't know the true answer to your question, but the reason why MOST "serious" drag racers run that style of wing is because that was what the last guy who beat them was running.

[skirkland1980]

Thanks. And by "serious" I mean cars running over 150 mph.

[johnc]

The differences in spoilers and wings between drag and road racing has more to do with the rules for each sanctioning body then anything else.

[skirkland1980]

After a lot of digging I found this article. Seems like the car in the video could have benefited from a front air dam. It just had too much airflow underneath. A good read but the writer couldn't find his space bar. http://www.hotrod.com/how-to/additional-how-to/hdrp-0609-aero-tricks-tips/

[RebekahsZ]

Guys going over 150 aren't that much smarter than you and me-they just spend more of their wife's money on their cars. They still buy parts for the same reason stated above. Or was that a poke because Ive only been 148? Haha! But seriously, I wonder if the mustang/X275 community has done an aero-comparo like the one done in the Wind Tunnel forum here? Basically those little horizontal wings off the hatch just lengthen the car, but I don't know what that actually does for downforce. I'm thinking that perhaps it has more to do with reducing drag, in theory anyway. I'm curious too, so I will look around and see if I can find any info, too. I'm at the beach wishing I was in the garage, anyway.

Edited March 24, 2015 by RebekahsZ

[SleeperZ]

That article made a point that makes sense to me, in that drag reduction is more important in higher speed events like drag racing and land speed events.  Wings that give more downforce are favored in road racing where speed through turns gains more advantage than straight line speed.

[RebekahsZ]

I searched a lot for wind tunnel testing discussions on this type wing. So far I have just found manufacturers claims. I don't know what a "wicker" is. That's what I will research next.

[skirkland1980]

http://iracing.wikidot.com/components:wing-angle-wicker

[skirkland1980]

Another new term for me is "dive planes".

[260DET]

In my opinion drag cars are LOL when it comes to aero, just looking at them in motion and it's obvious that air is getting under them and lifting the whole car which by any measure is costing them speed, let alone stability. I'm of course talking about production type drag cars whereas us circuit blokes learnt a long ago we needed good aero to go faster, in a straight line or whatever. Sorry if I've offended anyone but most drag racers strike me as being engine obsessed to the exclusion of all else.

[RebekahsZ]

No offense taken, but you are hanging out at the wrong dragstrips and concentrating your thoughts on the lower level cars. Take a look at modern funny cars and you will change your tune. However, drag racers have a lot more to consider than folks think. Often, the race is won or lost in the first 0.001 seconds of the race when the car is almost standing still. Not much speed to generate aero forces at that point. It is also because of aero concerns that the fast cars use 4-link suspensions with adjustments to keep the car down-the car that hoists the nose usually looses and often has lots of repairs to do when they get their broken stuff home. Drag racers do care about aero, but it is lower on the priority list for understandable reasons. Don't think I'm hot because of the long answer, I always write long posts. I still think that most racers use that wing for looks, same reason why most ricers slam their cars on the pavement. I sure as heck care whether my car looks cool, don't you?

[skirkland1980]

I'd say if you're hitting 200 mph and not flying off the track you have good aerodynamics.

[RebekahsZ]

And big balls!

[roger280zx]

If you're running 200mph with x hp you have good aero.  The other guy doing 200 might have twice the power.  In drag racing as with most stuff all things are relative.  The reason most street type cars go down the quarter mile gobbling air from underneath is because the center of gravity they require to get enough weight to transfer.  In other words a compromise, loose 3-4 mph up top, or 2-3 tenths due to lost traction... no contest.  As for the picture drag car wing it has much more to due with getting all that air out from under the car than it does actually loading the tires with "downforce".  Less lift is better, even if it still has a lot (in road race terms). 

[roger280zx]

Or you could put it in the words of Enzo "Aerodynamics are for those who can't build good engines."

[bjhines]

The other aspect to consider is drag and required downforce at required speed. 

The drag style wing produces less downforce but improves cd and stability. The drag wing has more consistent performance over a broad range of speeds.

The 3d style big-wing produces more downforce as speed increases but also has more drag as speed increases. The wing was designed to work best at a certain speed; and it is tuned to work best at certain parts of the roadrace track.

[260DET]

What bjh ^said ^ although I don't know what a 3d wing is. Done properly there would be a lot in working out when more downforce is needed and which wing profile would deliver that downforce at the lowest drag. Hmmmm, there might be a bit to this drag racing thing other than an engine

 

As well the location of the wing is important, the further back the more downforce on the rear wheels but if the wing is mounted behind the rear wheels then leverage starts applying a tendency to lift the front.