Page 1 of 2

Exhaust Idea

Posted: 16 Apr 2008, 18:18
by eiterndergoblin
hi folks

inspired by this :
http://www.formula1.com/news/technical/ ... 8/444.html

i thought about accelerating the air passing underneath the car with the help of the hot air exiting the exhaust pipes, by changing their position. would this be legal to use according to the rules ? would this be better than the hot air accelerating the air passing underneath the rear wing (as it is now ?!), wich causes a similiar effect ? (correct me if i´m wrong)
i´m quite sure the cooling problems wich would appear can be solved somehow ^^

here is an image of what i´m thinking about :

Image

here the url, if it doesnt work : http://www.bilder-space.de/show.php?fil ... qTRvaC.jpg

placing the exhaust quite in the middle would help avoiding huge tyre wear due to too much heat i guess

and here a cross-sectional image, for better understanding ^^

Image

here the url, if it doesnt work :
http://www.bilder-space.de/thumb/2OReOF6itmg6I4W.jpg

sorry for bad drawing skills xD
i just hope you understand what i´m thinking about ^^

Re: Exhaust Idea

Posted: 16 Apr 2008, 18:23
by Conceptual
I'm pretty sure that the teams used to do this, although I do not know the reason that they dont do it today. Possibly regulation related.

Chris

Re: Exhaust Idea

Posted: 16 Apr 2008, 18:59
by Jersey Tom
Used to be done. But with that, you start developing a strong dependency on engine revs for downforce. Not good. Hard enough to manage when it falls off so rapidly with speed.

Re: Exhaust Idea

Posted: 16 Apr 2008, 20:21
by Belatti
In 1998 Ferrari began to use the action-reaction principle, the same used to accelerate rockets: exhaust gases going up, pushes the car down.

Apparently then designers began to lean back exhaust pipes again, I suppose because it was disruptive for airflow.

I´m sure that in Top Fuel cars that huge 8 pipes pointing up must do a lot to press that car against the floor, and they are not in the way of rear wing airflow.

Now I´m thinking in placing a wing just after the pipe :-k

Re: Exhaust Idea

Posted: 16 Apr 2008, 20:35
by DaveKillens
About a decade ago, the exhaust used to exit the car down low, right inside the diffuser. Apparently though, changing revs would alter the gas flow, thus affecting the balance of the car. Get on the gas, more downforce via the diffuser. Get off the gas, less downforce. But imagine a car in a very fast sweeper, and suddenly a slower car was ahead. Get off the gas in a fast sweeper, the car loses grip... slip slide into the grass and worse. So eventually, the exhaust migrated away from the diffuser and exited on top of the rear of the sidepod. The fore and aft balance of the car was no longer affected by the position of the driver's foot.

Re: Exhaust Idea

Posted: 16 Apr 2008, 21:09
by modbaraban

Re: Exhaust Idea

Posted: 16 Apr 2008, 22:27
by eiterndergoblin
hm mkay
sorry guys, didn´t knew that
but nevertheless, thx alot

Re: Exhaust Idea

Posted: 16 Apr 2008, 22:40
by WhiteBlue
plus exiting in the middle would not be possible due to the "wooden" plank

Re: Exhaust Idea

Posted: 16 Apr 2008, 23:19
by CMSMJ1
Also due to the increased revs of modern engines the optimal length of the headers is shorter and so the periscope design is the only real solution.

I can recall a quote form the 80's where a "you could see the car squat" when the throttle was blipped!

Re: Exhaust Idea

Posted: 16 Apr 2008, 23:27
by RJC_pt
CMSMJ1 wrote: I can recall a quote form the 80's where a "you could see the car squat" when the throttle was blipped!
That quote was on brabham bt46 fancar....
Image

Re: Exhaust Idea

Posted: 17 Apr 2008, 01:23
by mini696
The downforce created by facing them up would be mimimal at best.

The teams dont guide them into the diffuser now because of the "waisting" of the cars. They gain more advantage having the car "coke-bottled" than the exhaust does producing downforce.

Also the diffuser is so small now, any disruption to the smooth flow would be negative. Having the exhaust sticking into the diffuser as shown above is again more negative than positive.

Tuning the differences in pressure at different revs would be even more difficult now because of the smaller diffuser too.

Re: Exhaust Idea

Posted: 17 Apr 2008, 02:09
by WhiteBlue
RJC_pt wrote:
CMSMJ1 wrote: I can recall a quote form the 80's where a "you could see the car squat" when the throttle was blipped!
That quote was on brabham bt46 fancar....
Image
Jeeze, look at those tyres.... FAT =D> =D> =D>

Re: Exhaust Idea

Posted: 18 Apr 2008, 01:28
by mini696
CMSMJ1 wrote:I can recall a quote form the 80's where a "you could see the car squat" when the throttle was blipped!
That was because of the extra suspension travel and softer spring rate of that era.

Re: Exhaust Idea

Posted: 19 Apr 2008, 13:21
by CMSMJ1
mini696 wrote:
CMSMJ1 wrote:I can recall a quote from the 80's where a "you could see the car squat" when the throttle was blipped!
That was because of the extra suspension travel and softer spring rate of that era.
I would have said the flat bottomed cars would run stiffer settings than modern day cars and certainly when the cars had skirts (or fans) the ride height had to be very stiffly controlled.

Do you not agree?

Re: Exhaust Idea

Posted: 19 Apr 2008, 19:59
by mep
But they moved the exhaust on top of the car wile they still
had the bigger diffusors, so the reason can't be the change in the rules.
I still wonder what effect it exactly makes to let them point up.
The effect must be better than leting point them into the diffusor.

The stability of the car is true but who cares on it.
The cars are designet to be fastest on one hot lap and the driver
simply has to get used to the cars handling.