mayhem

iTrader: (9)

Actually I would think the opposite may happen, but this would have to do with the overall aerodynamics of the car. More DF on the rear would effectively move the weight ratio a LITTLE bit more to the rear. Reducing front end DF. This would then relax the load on the front tires letting them absorb more transfered weight during turning before it overcomes the CofF between the tires and the pavement.

Secret Chimp

iTrader: (2)

Correct. More downforce on the rear will lighten up the front end. You want that sort of stability at high speeds.

As I understand it,

Maneuverability and directional instability go hand in hand (in cars as well as aircraft)....the more maneuverable it is, the less stable it'll be. Adding understeer (weight shift from front to back)adds stability at high speeds. this is a good thing.

Hallster

Mayhem, Secret Chimp,
I think you guys are confusing downforce,which has no mass, with vehicle weight, which has mass.... But rather then send this thread on a major tangent, lets see if we can get the aero data for our cars!

Don't get me wrong, I'd love to have a handling discussion, i just don't want to turn this into a 30+ page thread... at least until we get the info.

Thanks,

Sean

Thwack

yeah, pushing down on the back of the car isnt really going to make the front any lighter, taking load off the front.. it willmove the balance back, but only by adding weight to the overall car, and having it centered over the rear. the only way it will really affect handling is by giving the tires more grip by pushing down on them more, counteracting the lift that many cars get at higher speeds (the shape of most cars causes lift)

as for the canards, i dont see them doing too much of a difference unless you're going reeeeeeaaally fast... like at least 100 plus.. and even then, nowhere near enough effect to counteract how horribly ugly they look... if you want to counteract lift, lower the car, get an airdam thats close to the ground or a splitter. the less airstream you get under the car, the more downforce you will generate.

dryad001

iTrader: (27)

Maybe its kinda like back to the future.

"When this baby hits 88 mph, you're gonna see some serious S#IT"

Chris in HB

iTrader: (3)

I've read a couple of foreign sources (evo mag from the UK, others) about the function of the wing. The net result of the wing is not positive downforce, but zero lift at speed. This is what is truly important to road driving. For genuine downforce (above the lift negation), the angle of attack on the wing (the slant) would have to be greater. Also the shape of the back edge of the roof plays a big part as to where the air flows (ie over or under the wing element - the center part). I really looked into this a while ago when a lot of people were considering completely removing the wing. At highway speeds (well, at least legal hwy speeds), the wing's benefit will not be felt. Nor will it be noticeable on an autocross course. However on a full-size race track, the wing will help keep the car stable coming into the braking zones. I know the inevitable "Well the RS has no wing" comment will come, but that is generally to keep costs down and in Japan, it is assumed the purchaser of an RS is planning to upgrade everything on the car themself. I know it's long, but hopefully this helps. And last but not least, those of you with the small wing only get a fraction of the benefit of the full-size wing. Size does matter this time.

tweakdsm

iTrader: (38)

if you hit 155mph, its ready for lift off...

Chris in HB

iTrader: (3)

I can vouch for 140 - VERY stable...

1QWKEVO

iTrader: (3)

will reducing the the airflow below the car affect any of it's already "tuned components".... I know the underside of the vehicle has small things here and their to reduce lift or channel air for cooling.... Will it affect brake cooling and other stuff as well?... I'm looking to add some of the brake cooling guides and i'd love to see my car lowered but i'd rather not worry about warranty becasue i'm happy with the car stock...

Mach V Dan

iTrader: (19)

According to this excellent press release from Mitsubishi about the Evo VIII, the wing "generates 1.7 times more downforce than its predecessor...but incurs no extra drag penalties."

--Dan
Mach V
MachEVO.com

mayhem

iTrader: (9)

Actually because of the venturi affect (or was it the bernilli) the higher *flow speed* of the air underneath the car the greater suction to the ground you'll have. But the air will have to exit properly out the rear and not out the sides. The less restrictions underneath the better. For the sake of aerodynamics that is.

Chris in HB

iTrader: (3)

Yet another reason I wish we had a bumper with a diffuser...

Hallster

Thanks Dan.

Here's the section Dan was talking about from the press briefing doc:

"On its own, the spoiler generates 1.7-times more downforce than its predecessor
(with horizontal wing at the factory setting of 0-degree attack angle) but incurs no extra drag penalties.
To comply with WRC regulations and to reduce weight further, the spoiler uses a fixed-attack angle
horizontal wing in place of the adjustable angle wing on its predecessor. This, and the use of CFRP, has reduced
spoiler weight by some 2kg.
These advances in aerodynamics realize a significant reduction in overall lift and improvement in high
speed handling stability as well as improving the balance between front and rear aero characteristics. Evolution
VIII also boasts a coefficient of drag that is 0.01 slippier than VII."

-Sean

djsbadger

If the wing is generating 70 lbs of downforce at 60 mph, that equates to :

194 lbs at 100 mph

280 lbs at 120 mph

437 lbs at 150 mph

As far as the wings effectiveness, one of the magazines (Autoweek?) noted the RS felt less stable than the standard
EVO on the fast corners and attributed it to the wing.

trev0006

iTrader: (2)

can someone please explain why the RS model coming out has no wing? I thought the RS was made for racing.