I dont really understand why FWD cars uses those big rear spoiler to add rear downforce.

For RWD cars, it makes more sense because adding rear downforce pushes the rear wheel to the ground thus providing more grip to the rear wheel.

But for FWD cars, rear downforce makes front tires less grip. So why add a rear spoiler for FWD cars?

- Charles

Most road vehicles' aerodynamics generate rear lift at high speed. In racing, FWD cars use high rear spring rates to reduce understeer in low and medium speed corners. A rear wing counteracts the rear lift and keeps the car balanced in mid to high speed corners. If it's an adjustable wing it's also great for tuning balance in high speed corners while maintaining your lower speed handling characteristics based on spring and damping.

Gary
Sheehan Motor Racing
www.teamSMR.com

as odd it seems, cars need downforce on both the front and rear ends. Just because it is front wheel drive does not mean it does not need rear downforce. Think about it this way.... going around a corner on the track at around 100 mph and the rear slides around ( IE oversteer) Solution: more rear downforce to keep the rear end planted. Seems silly but it does have a purpose.

Most road vehicles' aerodynamics generate rear lift at high speed. In racing, FWD cars use high rear spring rates to reduce understeer in low and medium speed corners. A rear wing counteracts the rear lift and keeps the car balanced in mid to high speed corners. If it's an adjustable wing it's also great for tuning balance in high speed corners while maintaining your lower speed handling characteristics based on spring and damping.

Gary
Sheehan Motor Racing
www.teamSMR.com


this is the best response to any question on this entire board.

Drew
*goes to search for Gary's other posts*

yes, but how many civics with wings do you see going to tracks taking turns at 100mph?? :D think about it, i think the starter of the thread was talking about all the street drive pos cars with wings, not the track only cars...just a guess.

i agree. gary's response is the closest to perfect i've ever seen.

i think the poster WAS talking about track cars. who cares what the little boys do to their ricer-mobiles? if the OP wasn't talking about track cars, shame on you!!! :P

nate

can't be..... I see a lot of civic have dinning table size wing, I think they give those civic more horse power.

roc you are correct. It's true that on civics large wings and large stickers increase hp. The neat thing about civics is not the VTEC its the fact that hp can increase in direct proportion to the size of the sticker/spoiler. Contrary to popular belief the large exhaust tips on civics dont do anything.

A properly designed rear wing on a FWD car can also help reduce overall drag by improving the airflow underneath the car at the back as well as eliminating the rear end lift. A perfect example of this is the Realtime Racing World Challenge Acuras:

http://www.ppiclients.com/albums/557_16.jpg

Though it appears that the wing is actually pointing up, it is actually generating a little downforce because of how the air flows down the rear of the car, and helps the airflow behind the car. It is legal to run without the wing, and with a team that has as much testing time as Realtime, if it didn't help it wouldn't be there.

I was watching one of those wacky Options videos and they actually tested the Rear Wing FWD theory on a pretty worked Civic Type R in Japan (looked like a dedicated track car). They had one of their drivers run two or three laps first with the wing, then without, then with it back on just to confirm. The driver came back saying without the wing, the rear got pretty loose around the turns and with the wing was way more planted.

One more thing: In series that allow them, it's easy to generate lots of front-end downforce with splitters and airdams. You have to balance that out to maintain the handling balance.

For street cars though, it's pure cosmetics.