34 replies to this topic

[Dolsum]

Hello all!

This is my first time to post at this forum.
I have a big questions regarding aero setting for top speed in a F3 car.

Let´s put in this words: I do not care at all about handling, just care about top speed.

I tried many different combinations: (ride heights at the end of straight)
1.- Rear higher than Front (that logically gave the worst results).
2.- Rear lower than Front , but ride height quite low (Rear around 12mm, Front around 16mm).
3.- Same as before but higher (Rear 18mm, Front 22 mm).

Combination 3 was the one that expect to get more speed, but 2 was better, I expected that leting the air flowing more freely under the car will reduce the drag.

All the time was same wing settings.

Does anyone has an opinion about this?

Thanks a lot and wonderful site.

Pace for everyone in this world!!

Dolsum

[ivanalesi]

no toe in/out front/rear, may be rear camber.

[Dolsum]

I have tried less camber and also toe in/out zero, but did not give me 1 km!, I thought also that this could give me something. Thanks

Dolsum

[red300zx99]

Screw messing with the diffuser, take some wing out

[Ben]

Originally posted by Dolsum
Hello all!

This is my first time to post at this forum.
I have a big questions regarding aero setting for top speed in a F3 car.

Let´s put in this words: I do not care at all about handling, just care about top speed.

I tried many different combinations: (ride heights at the end of straight)
1.- Rear higher than Front (that logically gave the worst results).
2.- Rear lower than Front , but ride height quite low (Rear around 12mm, Front around 16mm).
3.- Same as before but higher (Rear 18mm, Front 22 mm).

Combination 3 was the one that expect to get more speed, but 2 was better, I expected that leting the air flowing more freely under the car will reduce the drag.

All the time was same wing settings.

Does anyone has an opinion about this?

Thanks a lot and wonderful site.

Pace for everyone in this world!!

Dolsum

Why do you only care about top speed and not handling?

Ben

[Beamer]

Do you do a standing start or are you coming out of a corner onto the straight?

[swaction]

I don't have the source, but...

BAR-Honda is to send a car to the Bonneville Salt Flats in Utah in October to see what the top speed of an F1 car can be in an out-and-out burst of speed. The BAR-Honda 007 is expected to be driven by James Rossiter and will probably feature no wings and perhaps a cockpit canopy. The car will also be fitted with a rear parachute to slow it down after the run, which are being staged as a promotion for Lucky Strike.

Interesting - Will the car be able to put the power down to the ground? I don't expect this to be much more than a publicity stunt as the thing that strikes most people about a modern day F1 car is it's cornering and braking...

[Supercar]

Originally posted by Dolsum
I tried many different combinations: (ride heights at the end of straight)
1.- Rear higher than Front (that logically gave the worst results).
2.- Rear lower than Front , but ride height quite low (Rear around 12mm, Front around 16mm).
3.- Same as before but higher (Rear 18mm, Front 22 mm).

Combination 3 was the one that expect to get more speed, but 2 was better, I expected that leting the air flowing more freely under the car will reduce the drag.

All the time was same wing settings.

Does anyone has an opinion about this?

Generally, the lower the ride height, front or rear - the lower the drag, and the highter is the top speed.

If the car does not handle well in a turn, the driver may tend to do through the turn slower but he will start accelerating sooner. The top speeds will increase.

The higher top speed does not have much correlation with lower lap times. Actually, on tight handling courses the correlation is exactly opposite.

Philip

[Dolsum]

Thanks for your many opinions.

Handling was not a problem, actually was quite good and cornering speed was ok, so exit also was ok, but the car start to loose speed after 200 km/h (top speed around 260, Monza). Circuits like this, top speed turn to be more important (talking about F3 cars), of course that you have to have the balance in cornering speed so your exit specially is good to get a god top speed, for example PARABOLICA is a typical corner where some drivers (unexperienced) try to keep a lot of speed (with the coming US situation), so they screw up totally the exit and at the end of the main straight they are 10-15 km/h down.

I was thinking that higher the car less drag, lower more downforce.

Great forum!

Dolsum

[Paolo]

Welcome in the wonderful world of induced drag.
Combination 3 lets airflow pass more freely ,true.
It allows, infact, more high pressure air from the sides to pass in the low pressure area that the underbody and diffuser are trying to produce.
This produces bigger vortexes than in situation 2.
Vortexes consume (lots of ) energy.
That's where your horsepower went.
Drag is not necessarily related to downforce. If you had sideskirts, you would have a lot of downforce, since very littlle high pressure air would spill to the underbody, and very little drag, for the same reason.

[wegmann]

I don't know the shape of the body, but ride height equal front and rear usually gives the lowest drag. Lowest ride height possible is also best. What else?

Zero toe, higher tire pressures, no wings, close off the air to the radiator as much as possible (without overheating the engine!), close off brake ducts (be careful when you stop!).

[ivanalesi]

If it flies over the bumps on the straight with those low settings you may have to soften the springs, if toe in/out doesnt give any top speed, just better accel., it means the car is running for some time at this top speed, right?

[Dolsum]

Yes, the car travel quite a long distance at that speed. I agree that if the track is bumpy I have to softening the spring to transmit the power to the ground.

I will try some of your ideas this weekend, and I will tell you after how was it.

Thanks a lot.

Till next time!

Dolsum

[charlie64uk]

If you´re running an F3,why don´t yyou refer to the Dallara handbook as it gives you the best
wing setups for the various wing configorations i.e mainplane.
What sort of engine are you running and how is your gearing?
What topspeed do you wish to achieve and at which track?

[Antoine]

Did you try a Mercedes engine?

[dc21]

Presuming you are running a Dallara, then I have to agree with Charlie, the Dallara technical manual tells you everything you need to know. Remember, Dallara produce a low downforce front flap and a low downforce rear top element. On the 99-01 cars the rad exit duct, the front barge boards/turning vanes and the rear tyre ramps also affect drag. I'm not sure which add-ons the newer cars have.

Dave

[Spunout]

BAR-Honda is to send a car to the Bonneville Salt Flats in Utah in October to see what the top speed of an F1 car can be in an out-and-out burst of speed. The BAR-Honda 007 is expected to be driven by James Rossiter and will probably feature no wings and perhaps a cockpit canopy. The car will also be fitted with a rear parachute to slow it down after the run, which are being staged as a promotion for Lucky Strike.

I found this story from 3 sources, but unfortunately none of them can be considered fully reliable.

[Dolsum]

Thanks again for your ideas.

Dallara manual is good, but does not give you really parameters to setup the car for max speed. Because the series where the car race are open for another car manufacture, the info is very restricted, for example they do not give you any aero data from wind tunnel testing, however they do in supernissan because is one make series or GP2.

They put in the manual diferent configurations (flaps, etc) but not info about ride height, so you have to find it by yourself!. Here is a point where teams with high budget can go to wind tunnel test and/or straight line tests or even better to a proper test track for aero test like IDIADA in Spain.

Also, I think is important to know when the car start to be stall (I think that is the english term when the wings doen not create anymore down force and no more drag), so you can put the car in this condition in straight line so you win speed. There is directely related to the RH of the car.

See you soon.

Dolsum

[Antoine]

The max speed configuration is without wings! you put out the front flap and the rear too or you put it at 0°!
For the ride height it's what you said!

but it's difficult to see the result without a pitot!

good luck,

i suppose it was for the Norisring?

[Antoine]

What do the other F3 teams?
do you look at the british F3 at monza?

[wegmann]

Originally posted by Antoine
but it's difficult to see the result without a pitot!

Sorry, a pitot? Pilot?

[desmo]

http://www.grc.nasa....lane/pitot.html

[Antoine]

a pitot, to mesure the air pressure and to know the air speed see by the car!

[Dolsum]

Hello all!

Yes I was looking at MONZA and Norisring as well. But after lask weekend at Nürburgring, I found out that (what was already written in one of the post) having a MERCEDES engine make life much much easier!. I do not have any doubt of Hamilton skills, but I would like to see him driving the same car with another engine, let´s say a TOYOTA for example. Sure is in top 10, not so sure about top 5 and certainly not sure about top 3.

Also, HWA brings to all MERCEDES team a set of "special" parts develop by themselve at wind tunnel. Last year also different suspension geometry as well. So make life more complicate to those that do not run MERCEDES. I hope it will change soon, or F3 is in troubles..

Regards

Dolsum

[Ross Stonefeld]

Yeah id like to see F3 go the Formula Ford route and run a spec tire and a spec engine, and just make it a chassis field.

[Antoine]

I don't know what engine you run but certainly not a Mercedes...
In my opinion there's between 0.6 to 0.8s:lap between an Opel and a Mercedes!
It's very significant on racetrack, this différence is less in urban track or on wet track!

For hamilton still leader of the championship without a Mercedes but he couldn't win so many race!

I hope that one day someone will demonstrate the différence between the engine, because guys like Perera, Duval, Rossiter, van der garde and so one are very good driver too.

Imagine at the Nurburgring is the mercedes was 0.7s slower in qualify 1 their will be these gap:

Di Grassi 23.709
Hamilton 23.815
Di resta 23.834
Bonanomi 23.949
Perera 23.965
Franchi 24.006
Moreau 24.029
VDG 24.082
Vettel 24.161
Duval 24.186
Rossiter 24.209
Guerrieri 24.348
Watts 24.398
Sutil 24.408
Hirate 24.443
Nunez 24.668
Abreu 24.745
Carbone 24.881
Neuhauser 24.93
Salaquarda 25.056
Holzer 25.176
Jelley 25.377
Kuhn 26.376


For second qualify:

Di resta 23.163
Di Grassi 23.275
Hamilton 23.338
Hirate 23.387
VDG 23.391
Duval 23.519
Rossiter 23.554
Franchi 23.593
Moreau 23.663
Perera 23.665
Nunez 23.673
Guerrieri 23.851
Sutil 23.858
Neuhauser 23.858
Bonanomi 23.918
Carbone 23.975
Watts 23.977
Holzer 24.035
Jelley 24.165
Abreu 24.544
Salaquarda 24.578
Vettel 24.733
Kuhn 26.299


It will be a lot more exiting!

[charlie64uk]

I know the problem,the car i run has an Opel engine and there is no way we can match the Mercedes this year.
The Merc engine is a thoroughbred race engine specifically with F3 in mind,it being at least 15kg lighter than the Opel,and thats a lot of ballast that can be spread out around the bottom of the car.
Unfortunately reducing wing does not let us pick up top speed to make a noticable difference on the straights.
Nürburgring was particularly bad as there was a lot of understeer in the first section which necessitated a rather large amount of front wing to help combat this.The big drawback was a speed loss on the run down to the chicane.

[Antoine]

Charlie64uk, you can look at all the previous race, but each time there was a qualify in dry condition and on permanent track there was 0.6 to 0.7s difference between the Opel and the Mercedes!
Even if you considere that Hamilton is a super star, and you compare the time of the second Mercedes or the third Mercedes with the second or the third opel, it will be the same gap!

Sorry for the Opel, hope it will rain for the 3 last event!!!

[charlie64uk]

Antoine,i agree with you but there is nothing that can be done.At least last week i had a little luck and we only had two mercedes in front.

[Ross Stonefeld]

These past two years its been as much about ASM as Mercedes

[Antoine]

I don't think ASM is a lot more competitif than the other, they just make less mistake for me!
If you look at Nurburgring, it was Manor on the front row, but ASM win the 2 races
At Monaco, Manor was nowhere, why? like at Pau and so one!
and di resta made some good one too sorry!
but it's like that ASM is strong, and noone with a Mercedes is as strong! if you are but with an Opel you still 0.7s behind!

Hirate make 2 very good race, for sure! and we all hope for a crash in the first corner and for two first row

[chrisbeatty]

Originally posted by Spunout


I found this story from 3 sources, but unfortunately none of them can be considered fully reliable.

Here's some info, from a local source, it seems Alan van de Merwe is driving & the actual speed attempt will be in October

http://tinyurl.com/8vomt

[Dolsum]

Hello all.
I agree that Mercedes engines are faster, I do not know if 0,6 - 0,8 sec a lap, just faster.
Another interesting point at Nürburgring was that an unknown driver like Neuhauser, qualify 5th and finished 4th (of course Merc engines), so the question is: If he was able to be there, lapping very similar times like Sutil for example, then even if you are a meddium level driver, you look like a really good one just because you have the money-contact-etc to have a Merc engine?

But this is racing, and if Mercedes did a really good job in last years, investing a lot of money and time, is logical that they reach such a high level so quick, I hope Spiess can make an step..

Regards

Dolsum

[charlie64uk]

Sure the only way to go is use the Mercedes engine.
Neuhauser obviously benefitted from the qualifying engine mapping but was slow throughout the first section of the track and could only catch Hirate on the straight sections.
Hirate was setup to use a lot of downforce to get him through the first section but lacked top speed on the run down to the chicane.
Neuhauser was not able to catch up at all and the gap remained constant throughout the race.

[dc21]

Does anyone know why Mercedes won't allow their engine to be leased in the UK? The engines in the UK series seem to be pretty evenly matched, I'm sure the better funded teams would love to get their hands on one. Is the Spiess really that far behind? Their seems to be a close collaboration between Bosch and Spiess. Is the same true of Bosch and Merc?

Dave