Technical Regulations for 2009-2015

[PNSD]

At about 70mph, so about 110kph I thought F1 cars produced roughly 600Kg of downforce? I always remember thinking that at the British speed limit (70mph) an F1 car has downforce equavilent to its weight. Then at about 150mph the downforce was somewhere in the region of 2000kg? But I could way of with that.

Ogami musashi - I just dont see how this level of downforce can be produced in practical way for say a road going saloon. Ive always wondered why cars dont have bolt on flat underbodys to reduce drag and increase fuel. As far as my limited knowledge goes it would not be too difficult to implement something like that, but since it is not being done apparently it is difficult.

[Ogami musashi]

2006 Monaco trim gave 1550kg@ 240km/h thus 445kg at 130km/h.


Downforce levels have to be correlated to weight for comparision. This would equal 800KG for a saloon car.



200kg downforce could be obtained by blowed venturis like it is the case in 599XX (135kg at 130km/h).

This way the DF curve is not parabolic and can be controlled so that DF doesn't go too far preventing dangerous high speed cornering.

[WhiteBlue]

Ogami, if your figures were applicable to F1 a rear wing would have 78% efficiency and a diffusor/venturi would have 92% efficiency. If I do a simple average the typical F1 aero efficiency would be 85%.

Let us further assume that we have 2 tons of downforce at high speed, say 300 km/h. So our braking force according to your view would be 15% of two tons or 3000 N roughly.

We also know that the typical deceleration by drag alone is 1.5-2 G. The mass is 620 kg at the end of a race. 1G is 9.8 N/kg

F=a*m

F= 620*1.5*9.6 N=9300 N

You see that by a simple and practical calculation it becomes clear that the drag is more than three time what you make believe. In fact the real aerodynamic efficiency according to this calculation is closer to 55% than to 85% as you claim. We are back to the old rule of thumb that almost half the power we use to generate downforce will be used to generate drag and turbulence.

[Ogami musashi]

Ogami, if your figures were applicable to F1 a rear wing would have 78% efficiency and a diffusor/venturi would have 92% efficiency. If I do a simple average the typical F1 aero efficiency would be 85%.

I don't understand your %..from where they come from?

We also know that the typical deceleration by drag alone is 1.5-2 G. The mass is 620 kg at the end of a race. 1G is 9.8 N/kg

Flawed...

There would certainly not be 1,5G-2G of deceleration with a total solution 2 times more efficient than an actual car..

[WhiteBlue]

Ogami, if your figures were applicable to F1 a rear wing would have 78% efficiency and a diffusor/venturi would have 92% efficiency. If I do a simple average the typical F1 aero efficiency would be 85%.

I don't understand your %..from where they come from?

Ok I will go slow to show you.

You say the rear wing has a DF/drag ratio of 3.5/1. That means the total force is 4.5 units and the DF 3.5 out of this. Efficiency is 3.5/4.5=78%

You say the diffusor has a DF/drag ratio of 11/1. Total force is 12 units. Efficiency is 11/12=92%

Now we simply take the average from the wing and the diffusor which gives us 85% efficiency for the F1 aero solution. Primitive but it should at least hit near the actual number. The drag should now be 15%. If we use 2 tons we arrive at the 3000 N.

We also know that the typical deceleration by drag alone is 1.5-2 G. The mass is 620 kg at the end of a race. 1G is 9.8 N/kg

Flawed...

There would certainly not be 1,5G-2G of deceleration with a total solution 2 times more efficient than an actual car..

I have used only the smaller number of 1.5G for deceleration by drag. If you use the brakes the car have 5.5G. So in my scenario without brakes 1.5 G. So if you step off the throttle only the drag brakes with 27% of the total braking force.

F1 Engines have 550 kW. This is the power that was used to overcome the drag. F1 brakes have 1800 kW. Together you have 2550 kW total power for braking. So engine has 24% of the total braking power. You see the G-force and power comparison shows very similar percentages. If I correct the drag induced breaking to 1.35 G I'm exactly at the 24% of the total breaking power. If I do that I'm still getting 8035N drag force which is way more than you get with 85% efficiency.

So now I say the drag breaking is 1.35 G. The drag force is 8035 N. The DF/drag is 2.5. That is miles away from your figure of 11 or even 3.5.

[Ogami musashi]

I have used only the smaller number of 1.5G for deceleration by drag. If you use the brakes the car have 5.5G. So in my scenario without brakes 1.5 G. So if you step off the throttle only the drag brakes with 27% of the total braking force

No you misunderstood the problem.

The will NEVER be 1,5G of drag for a car that would have a venturi worth of 11/1 ratio or even 8,5 L/D ratio.

First off, the figures quoted for F1 cars are 1g*, not 2G;
You logic is then fasle in many points:

-A car wouldn't have to be fitted with draggy wings; A simple venturi (like this is done on 599XX) would give even with let's say 7/1 @ 289 km/h (with 700kg of), 100kg of drag which would equal to 0.2G of deceleration.

-The example you've taken is irrealistic...you take a car at 300km/h...a road car would never do that; Even with a 3.5/1 ratio you would have 0.01g of deceleration...


-Even a F1 car with a wing of 3.5/1 ratio at 130km/h would have 0.3G of deceleration.

So now I say the drag breaking is 1.35 G. The drag force is 8035 N. The DF/drag is 2.5. That is miles away from your figure of 11 or even 3.5.

You completly get the problem wrong sorry... the venturi had 11 of ratio and the total car had 7.7/1 ratio..meaning that at @300km/H for 2000KG of DF you have
(20000/7.7)/620= 0,5g of deceleration...

There nothing complicated in those maths... a car that produces 2000KG of downforce and has a 7.7 L/D ratio produces 7.7 times less this amount, that is 2000/7.7 that is 258.7 kg.

Some help for you:

http://www.mulsannescorner.com/aerodata ... lmp03.html

Simple, practical calculations as you say...



*The 1G figures for F1 cars are because typical F1 wing has 3.5/1 L/D ratio.
for cars having 2000KG@ 300km/h than makes 2000/3.5= 571 kg: 5710/620= 0.93g's.

[godlameroso]

Is everyone against having fully adjustable or active wings? Especially in combination with a flat floor, and a much improved KERS HERS combo. Imagine 780 h.p. 1.5 4 cylinder turbo engines running off bio-butanol getting 15-18 m.p.g. The cars would be able to finish the race with a full 22 gallon tank. Instead of the 40 gallon monstrosities we currently use.

[Ogami musashi]

Oh..a designeer explaining why IRL cars have difficulties overtaking:

The current Dallara Indy car loses much of its downforce when it swings through more than two and a half degrees in yaw angle. This is a key reason why it's so difficult for the drivers to be able to pass each other.

And

"We've also designed the aero package to run in traffic better than the current car. In fact, it's twice as good in terms of retaining the downforce when you're running a car length behind. This is critical because if the following car loses five, ten or twenty percent of its downforce there's no hope of getting through the corner. Even one percent loss of grip is a sufficient detriment that you can't get on terms with the car ahead of you. We worked very hard to disciplne ourselves to take aero solutions that didn't halve the aero performance of the following car and I think we've managed to do that to a very significant degree."


© Ben Bowlby The absence of traditional front and rear wings is another factor in the improved responsiveness and raceability of the Delta Wng concept.

"The removal of wings ahead of the front axle and behind the rear axle and their interaction with the underbody and the car and their wake characteristics all help to put all the performance in the underbody," Bowlby says. "This method of creating the downforce makes a very efficient and stable package with a very low yaw sensitivity to the downforce and very high efficiency from a lift-to-drag ratio standpoint. I think we're going to have a car that feels very light, is very nimble and can be taken to high slip and yaw angles without compromising the ability to control the car.

http://www.gordonkirby.com/categories/c ... no235.html


Gosh, that would mean the problem is not as simple as Level of DF??? Would it be geometry in addition to finess over wake strength like i posted before???


Oh my god...i'm not credible after all..sure this guys is not neither posting the same things i said..

[wesley123]

Wow, that message explains alot. There is actually mroe overtaking in IRL, those quotes actually prove that it is nmore drivers and racing rules then the cars itself

[WhiteBlue]

No you misunderstood the problem.
The will NEVER be 1,5G of drag for a car that would have a venturi worth of 11/1 ratio or even 8,5 L/D ratio.
First off, the figures quoted for F1 cars are 1g*, not 2G;
You logic is then fasle in many points:
-A car wouldn't have to be fitted with draggy wings; A simple venturi (like this is done on 599XX) would give even with let's say 7/1 @ 289 km/h (with 700kg of), 100kg of drag which would equal to 0.2G of deceleration.
-The example you've taken is irrealistic...you take a car at 300km/h...a road car would never do that; Even with a 3.5/1 ratio you would have 0.01g of deceleration...
-Even a F1 car with a wing of 3.5/1 ratio at 130km/h would have 0.3G of deceleration.

You completly get the problem wrong sorry... the venturi had 11 of ratio and the total car had 7.7/1 ratio..meaning that at @300km/H for 2000KG of DF you have
(20000/7.7)/620= 0,5g of deceleration...

There nothing complicated in those maths... a car that produces 2000KG of downforce and has a 7.7 L/D ratio produces 7.7 times less this amount, that is 2000/7.7 that is 258.7 kg.

Simple, practical calculations as you say...
*The 1G figures for F1 cars are because typical F1 wing has 3.5/1 L/D ratio.
for cars having 2000KG@ 300km/h than makes 2000/3.5= 571 kg: 5710/620= 0.93g's.

I havn't misunderstood anything my friend. The problem is that you keep putting up irrelevant numbers instead of giving one efficiency for a contemporary F1 car or one DF/drag ratio you quote separate figures that do not add up. The first time we have been talking hard numbers here was when I looked at the power consumption by the engine and the brakes. It is logical that at full song on a straight with 300 km/h all the engine does is overcoming the drag. This is the reason why we can identify the drag force by the pedal lift deceleration.

I have given you the break down of the 5.5 G of an F1 car at maximum speed of 1.35G for drag and 4.15 G for the breaks. I have also substantiated the split by showing that the power needed of 550 kW for the engine and 1800 kW for the breaks splits exactly at the same proportions. The drag is substantially higher than you believe, in fact it is 8035 N, which is 35% higher than you think.

When we apply this hard figure to the DF/drag ratio of the total car we see that we get 2.5 which is a lot worse than the artificial figures that your quote for single irrelevant devices.

I am quite prepared to revise my numbers if you show me that I have introduced wrong figures, but I'm quite sure that 550 kW for the engine, 1800 kW for the brakes and 5.5 G for total deceleration are pretty good. Until such time I will stick to my believe that we have too much downforce and particularly too much drag and turbulence with the current generation of F1 cars.

Back to the debate about DF for cars and trucks: The members here have clearly stated that they would do pretty much everything to get better fuel milage out of their vehicles. They certainly do not need to waste more fuel to get aerodynamic downforce except for the happy few who drive 200 mph super cars.

[Ogami musashi]

I havn't misunderstood anything my friend.

Yes you did, and i'm afraid you still do not get why.

YOU told me using downforce on a saloon car would cost a lot of drag;
I pointed to you that it is possible to design efficient aeros with very high numbers of L/D and for that sake i pointed at you at a COMPLETE CFD test series done by RDV with a generic F1 car were the venturis would have been not limited like they are now in F1 with the result of having very high (7.7/1) L/D for the entire car.

I took the example of the 599X to show you that in addition to that CFD, real cases active aeros (that is aerodynamics where DF is not necesserily a parabolic function of speed) exist and that of course a 599X doesn't have 1,5G of drag or it would be completely impracticable.

All to show you that technology exists, that an F1 could do that and i've supported the CFD example by the article on deltawing indy car that has HALF the drag for the same downforce (in fact the downforce is planned to be higher) all thanks to higher efficiency due to venturis.

And you keep talking about a F1 car with 1.35G of deceleration...which is not correct by the way (the actual cars do not have 1,35G of deceleration).

Now..coming from the simple calculations i've done and that i've mentionned from the start active aeros could be used to decrease DF at speed (and it exists too..) i don't see how you can still maintain that usage of DF in saloon cars would cost too much energy.



And to end up; on the subject of Wake..the article shows that real example of cars where loss of downforce is reduced by large proportions only by improving finess and geometry is possible meaning that both the wake intensity and its effects are not related to DF levels directly.

[WhiteBlue]

.. you keep talking about an F1 car with 1.35G of deceleration...which is not correct by the way (the actual cars do not have 1,35G of deceleration).

I have told you that I believe you are wrong there. I have given you the power figures to substantiate my claim. You have not even attempted to criticize my figures or methods of computing G levels for engine and brakes.

And to end up; on the subject of Wake..the article shows that real example of cars where loss of downforce is reduced by large proportions only by improving finess and geometry is possible meaning that both the wake intensity and its effects are not related to DF levels directly.

This thread is about future F1 specifications and regulations. I maintain my point of view that current rules create no incentive for F1 designers to reduce drag. They still have incentives to increase the downforce and in most cases this will also increase drag. Only if the downforce is legally fixed they will start to reduce the absolute drag because that will be the only way to use aero to make the car quicker. This is why F1 should fix the downforce.

[Ogami musashi]

I have told you that I believe you are wrong there. I have given you the power figures to substantiate my claim. You have not even attempted to criticize my figures or methods of computing G levels for engine and brakes.

I think we completly misunderstand each other; If you base your calculations on an actual F1 wing (With 3.5/1 LD ratio) your drag estimate is okay(it is lower than that; with 3.5/1 ratio you have 1G of drag but a wing ratio will change with AOA and since a car is not fixed it will change according to speed).

What i tell you is that, if you keep downforce as a possible road relevant technology there're means to make it far less draggy and i've given you concrete, hard data, examples and thus, with such a solution (either with venturis and/or more efficient wings) you can achieve that; HENCE why your 1.35G data in those cases aren't good.

The basic logic is that the higher the L/D ratio, the lower the deceleration.



To finish up, that there's no incentive in F1 to diminish drag is pretty evident.
But examples like LMP and Indy car projects shows that it is not impossible at all.

Even before that, the foruma nippon 09, car had a 50% increase in downforce with 20% reduction in total drag.

Conversly, you can cut downforce, but geometry and finess have to stay on par at least to have the good benefits of cutting downforce; else the wake will stay as damaging.

[domo777]

Did everyone miss this? It was mentioned by Ross Brawn in the BBC pre qualifying interview and I managed to find it here. You guys forced me to register!

...drivers will next year be able to adjust the angle - by a factor of 50mm - of the rear wings, meaning that straight-line speed can be dramatically increased when the cars are not negotiating corners.

The intriguing twist, designed exclusively to boost overtaking, is that only chasing drivers will be able to adjust their cars' wings.

A green light will shine in the cockpit when a car is close enough to the rear of his rival, thereby allowing the driver to trigger the rear wing button.

The systems will not be available to drivers during the first three laps of a race, but the wings may be triggered after a safety car period.

http://paddocktalk.com/news/html/story-137890.html

[WhiteBlue]

There is a dedicated thread just for this Gimmick.