When Does Downforce start mattering?

[**Ghost**]

Always been interested to know at what speeds does downforce generated by a car actually affect how much the tyres grip?

We all know that F1 cars generate enoguh downforce to have them drive on the roof etc etc... but they're going at 300KM+

Please note my question is not about "height" of a car...of course a car will handel better if it has a lower centre of gravity. I'm asking about downforce in particular

[ekslut]

I beleive it starts making a difference at about 80km/h

[City Turbo]

I wouldnt think it would take effect until atleast 150kph+
Its not as simple as sticking a twing on either which is what many people think hehe

[**Ghost**]

i heard it had more to do with the undercarriage than the wings and body kit...

i never expected 80kmph for downforce to become a significant factor... ne othe ropininos?

[tinkerbell]

nah, it is well over 110km/h i have heard.....

my ITR body kit certainly feels good at high speed, but i am only comparing it to a DA9 previously...

[SiReal]

apparently, as quoted by commentators on F1, the little front spoiler on the front lip of ur car may do alot more than a big wing.

[bennjamin]

ditto from what ive heard - altho the type of downforce and location all come into play too i should think .

[bumography]

i think it comes down to the shape and weight of the car.
Say in a formula 1 car, the downforce should affect the car at a lower speed than say an old volvo due to the lightweight and body of the f1 car contributing largely to the downforce.

Of course this is just my theory, which proves you all wrong hehe

[froggy]

on F1 cars each peice of the body has to be perfect or else the car will just fly... last time i was watching a tiny peice of the wing broke of and the car spun out...For normal cars wings are useless unless your gonna be going super duper speeds

[Tobster]

Cars with extendable spoilers like those found on many Porches or on the Chrysler Crossfire don't extend until about 90-110 km/h -- but these are rear or all-wheel drive cars which will want more downforce at the back to keep the powered wheels on the ground.

I remember reading about the Alfa 156 GTA in (I think) Motor when it was released in Australia. They drove it through the NT so they could really get it up to speed and a lot was made of the fact that it was the lower body work (particularly the under car air flow) that helped keep it steady at high speeds -- and that's a front-wheel drive car that didn't have a rear wing.

Like everyone says, all depends on the shape of the car and what type of driving you do...

[ekslut]

i heard it had more to do with the undercarriage than the wings and body kit...

i never expected 80kmph for downforce to become a significant factor... ne othe ropininos?

I never said that it would become a significant factor at 80km/h. I said it would start to take effect about then.

For it to be a significant factor I think you would have to be in the mid 100's somewhere.

But I had a friend who ran a spoon rear wing on his EG. He took it off (had nothing) and said it felt a lot looser at the rear end, and he was oversteering more. And this is driving medium to hard on the streets.

[aaronng]

I never said that it would become a significant factor at 80km/h. I said it would start to take effect about then.

For it to be a significant factor I think you would have to be in the mid 100's somewhere.

But I had a friend who ran a spoon rear wing on his EG. He took it off (had nothing) and said it felt a lot looser at the rear end, and he was oversteering more. And this is driving medium to hard on the streets.
That must have been a heavy wing!

[**Ghost**]

hmmm well my mugen wing extends a LOT, so mebbe that would help :P nah j/k

well on the topic...how well sorted are factory aerodynamics on hondas neway? not that it would really matter since u'll rarely go insane speeds neway

[Tobster]

I know that the drag coefficient on the Accord Euro is about 0.26 or 0.27 -- which is about as good as you'll get on a factory sedan. As far as I know, your average sedan is about 0.32.

Honda always strike me as a manufacturer who don't go unecessarily overboard on the the cosmetic dress-ups; i.e. they don't seem to put wings on things just for the look -- and presumably they take into account their Grand Prix experience. I tend to look at what they do with their "go fast" models: the Integra Type R had the wing, so I'd presume that the rear can get a bit untidy since it was so hard sprung. The Accord Euro R has no spoiler, just a lower body kit. The S2000 has a subtle lip spoiler...

While big wings might help keep you steady, they cause a lot of drag and can slow you down and limit the top speed. I would say it depnds on how the car feels for you -- if its getting untidy, and it's not a suspension issue, start playing with aerodynamics...

[aaronng]

Have you read the info on autozine.org's technical school section? Very good info on drag, downforce and lift.
http://www.autozine.org/technical_school/aero/tech_aero.htm#Drag

[weezer]

i was speaking to a guy at Phillip Island and he said that when he used to have a GT wing on his CRX he did a slower time than with no wing. He said that he was getting too much downforce and would slow him down in the straights, even though it gave him more stability around corners. He then fit an M3 type Lip spoiler on the car and that gave him a bit more stability around corners without compromising top speed.

[mini_s2000]

thats true weezer!
when having a front lip spoiler on your car your reducing the amount of air travelling under your car and creates a better air flow when travelling at high speeds and cornering... as well as the GT WING it creates a drag on the rear of your car! but there some cases when having a wing on the rear of a car designed to help stability. eg; audi tt need that little rear wing so they dont spin out at high speeds!

[EG5[KRT]]

i know when i used to go to track in my old car once u get past 130 the car feels really unstable and a littlest of movements made the car very wishy washy...

i think with subtle lips and spoilers it does help but to what effect.. thats when u invest in a lip or wing made by a devloper that has put the RnD into the part and can prove that its a useful item.

even when driving on the freeway in my civic at about 130 the back seems very light.. and when u change lanes the back feels very loose ..

[krasyvy]

track it with a 15inch sub in that back, that will keep the rear end down

[sivic]

']
even when driving on the freeway in my civic at about 130 the back seems very light.. and when u change lanes the back feels very loose ..
thats more of an issue of suspension setup. firmer struts will help this but adjusting the toe angle of the rear wheels will help even more. having the toe angled in (negative toe) will make your rear end more stable at high speeds. however, the drawback of this means that at lower speeds you wont be able to turn as tightly

[EG5[KRT]]

so wouldnt the rear spoiler help that ? due to down force without having to muck around with stuff at low speeds ?

[EG5]

our EGk20a gain 2mph down the 1/4 mile after we took the spoon cf duckbill rear wing out.

[**Ghost**]

our EGk20a gain 2mph down the 1/4 mile after we took the spoon cf duckbill rear wing out.

thats quite a bit of difference in the level ur competing in :)

so aerodynamics is not something daily driven, non-competition cars shoudl worry about yeh?

just a point of interest, the obscenely big CWEST kits...they are just for looks right...i cant imagine them being good at aero

[vividjazz]

They said it STARTED from 80km/hr for the indy cars during the race on the weekend.

[EG5[KRT]]

drag cars is diff tho

on track is different at high speeds... need stability at high speeds.

straight line is just straight line .. no need for down force at the rear.

[vinhy]

just a point of interest, the obscenely big CWEST kits...they are just for looks right...i cant imagine them being good at aero

the cwest kits are not for looks. i have two clips (which you can get from their website) of them wind tunneling their s2000 and rx7 and then testing it at tsukuba circuit. they compare the difference between the original kit and their kits. improved lap times by 2-3 seconds.