31 replies to this topic

[Ali_G]

Just to clear this up guys. Martin Brundle seems to have drilled this into yer heads that its turbulence coming off of the back of the cars that is hindering passing. That really is and utterly wrong.

The real problem is that the cars have become aerodynamically efficeint so they are not giving off enough drag and enough of a slipstream.

If you want to blame anyone for lack of passing blame Ken Tyrrell

He intorduced the Splitter - Diffuser arangement which created a lot of downforce from the underside of the car. This meant that the car could create the same amount of downfoce with less drag.
So it mean that there was less of a slipstream coming off of the car.
Remember the 80's. All of the passing. Ever notice that passing became way less frequent in about 91 - 92 when everyone started introducing the Splitter - Diffuser arangment.


So there is one way to get passing back.

That is to ban splitters and diffusers and allow unlimited running of elements in wings and lower the front wing by 50 mm again.

Anyone else agree.

Niall

[Darren Galpin]

I agree and disagree. The problem is that the front wing generates far more downforce than it ever used to, so the front of the car is now much more sensitive to a lack of grip. The dirty turbulent air from a car in front means that you get less clean air over the following front wing, so it generates less downforce. Hence the following car cannot corner as quickly.

HOWEVER, the aerodynamics of the cars these days are so good that the amount of turbulent air behind a car is actually very small, so you need to be underneath the gearbox of the car in front to lose the downforce. On the straight, however, the turbulence is beneficial, as it is the turbulence which generates the suction effect we call a tow. So we have two competing problems: a front wing which is too sensitive to a lack of clean air, which hinders cornering closely, and a lack of turbulence to generate a tow. So what is needed is raised front wings with restricted elements to allow cars to follow closely in corners, and a door stuck to the back of the car to create huge amounts of turbulence to allow a decent tow on the straights,

[Clatter]

Many of us have been saying for years that they should ban the diffuser.

Several drivers (DH springs to mind) have said the same thing when asked what they would change. The only one who doesnt agree seems to be MM.

[baddog]

In a way you are wrong and right.

The older cars created a big hole in the air nehind them, which you rightly talk about generating the slipstream.. but it isnt so much there being less slipstream, as the air IN the slipstream (especially in the crucial ground area) being much more disrupted by the diffuser.

Of course if the cars werent so reliant on their front wings we might see this affecting slipstreaming less. in fact we are seeing this already.. anyone ELSE noticed the odd slipstream pass slipping into F1?

Shaun

[Ali_G]

Still though that Splitter Diffuser arangement creates a lot of downforce with a lack of Drag.

Niall

[Gruff]

Quote

Originally posted by Ali_G
Just to clear this up guys. Martin Brundle seems to have drilled this into yer heads that its turbulence coming off of the back of the cars that is hindering passing. That really is and utterly wrong.

Anyone else agree.

No. No I don't agree with this inaccuracy. Yes, the diffuser DOES make a huge contribution and all that other stuff people have mentioned, but as my University aerodynamicists, lecturers and demonstrators have 'proved' that turbulent air really affects aerodynamics, so Marting is correct when he says it hinders passing. It does, just maybe not as much as some people think.

[Ali_G]

Think about this though.

Pre splitters, there was a lot of passing. Yes the drivers then also complained about tons of turbulence. But the difference was that the extra slipstream coming off of the back of the car mae it possible to pass.

I make the example of the 89 Brazilian GP at Rio.

Mansell kept trying to pass Prost. But in every corner the turbulence stopped Mansell from getting past. Coming on to the back straight Manell was a distance behind due to the turbulence. Yet with such the drag off of the cars at the time he had passed him half way down the straight.

Niall

[Gemini]

Turbulence has one more effect on a car behind. I read somewhere that sometimes turbulence is so strong that it has impact on engine power output, because of less efficient air intake.

[Simioni]

I always got the impression that what really hurt overtaking more than anything else was lowering the rear wings in 95.

[Limey]

I agree with Ali_G. Take the case of a NASCAR stock car. The air flows over the car creating a 'hole' behind. The air flowing under the car is minimised by the front spoiler under the bumper. This enables a car following to 'slingshot' by using the 'hole'.

Also in CART when the Hanford wing was introduced to increase drag, the resultant effect was to create a 'hole' behind the car enabling a following car to do the same as the stock car.

One of the ways to increase grip on an F1 car was to design the underneath to accelerate the air flowing under the car. Regulations may have decreased this effect but it is still happening.

If the air on an F1 car flows from under the car as well as over, the 'hole' behind is a lot smaller. This will also unbalance the car following as this air from the difuser is trying to flow under the wing of the following car.

However it is probably very difficult to minimise air flowing under a formula car as the frontal area is a lot less than a stock car.

[desmo]

I disagree, the turbulent air behind a car reduces the effectiveness of the aero kit of the following car as far as producing downforce. The CART example is flawed by, among other things, the fact that the cars there in oval trim are MUCH less dependent on aero grip than F1 cars. Just look at the front wing of a CART car in oval trim. The NASCAR example is even less on point as they have no wings at all!

The difficulty of overtaking in F1 is largely down to the ratio of aero downforce "grip" to mechanical tire grip being biased too far in the direction of downforce. Niall's suggestion would not help at all. IMO, the best way to make overtaking more feasible in F1 would be to eliminate the groove tires (although it must be said that the current tire war has helped in this regard by enormously improving mechanical grip) and limiting the total plan area of the wings.

I actually think the combination of the tire war with it's grippier tires and the raising of front wings should make overtaking significantly easier this season than it has been the past couple. We shall see.

[Ali_G]

Simioni could also be on to something there with lower rear wings. To be honest this is the frist time I have heard of this.

FOr what purpose were the rear wings lowered anyway.

Niall

[Limey]

I don't agree that CART cars on ovals are MUCH less dependent on aero grip. The wings may be smaller but downforce increases at a rate that is proportional to the speed squared (or maybe cubed).

A wing on a car is designed to move the air over the car, the diffuser negates this effect. That was why skirts appeared on F1 cars to cut air under the car. When they were banned, the easiest way to overcome this was to accelerate the air under it.

[desmo]

It is velocity squared, as all aero effects including drag are. I cannot prove my hypothesis as actual downforce figures for both series are not divulged. Can we agree that on a small (~1 mile) oval that is the case anyway?

"A wing on a car is designed to move the air over the car, the diffuser negates this effect."

Actually a wing is designed to create a speed differential between the airflows above and beneath it to cause a static pressure differential and thus lift (downforce).

"That was why skirts appeared on F1 cars to cut air under the car. When they were banned, the easiest way to overcome this was to accelerate the air under it."

Actually the undercar aero works on the same principle as the wings creating a velocity differential and thus a static pressure differential between the undercar flow and the flow above the car. The skirts were simply to keep lower velocity and hence higher static pressure air from diluting the velocity of the undercar flow. The idea was always to accelerate the undercar flow, skirts or none.

[Eau Red]

Quote

Originally posted by Ali_G

FOr what purpose were the rear wings lowered anyway.

i think to make them less efficient, by not letting them use cleaner air above the rest of the car.

[Ali_G]

Ban all undercar downforce making parts.

Raise the rear wing. Let them use 4 elements in the rear wing.

Lower the front wing by 50 mm.

This should increase passing.

Niall

[Damop]

I agree with Desmo. The fact is that the cars are very sensitive to disruptions in the air flow. More turbulent air results in less downforce from the front wing, which increases understeer. Therefore passing a car is very difficult unless there is a large speed differential between the two (i.e. a Minardi and Ferrari).

To highlight just how crucial the airflow on the front wing is, ever notice in CART and F1 when a car is understeering they will dial in one or two more turns of wing? Well, that results in a minute adjustment in the wing that isn't even perceptible by eye, yet it can have a dramatic effect on lap times of several tenths a second, not to mention improving tire wear. We saw an example of that in Melbourne this past weekend.

[Ali_G]

Damop: Yes but the cars were stil having this problem 10 years ago. The only difference was that the cars were gving off a better slipstream. That is what they need now aswell.

Niall

[RJL]

1. Widen the wheel track back to how it used to be.
2. Give 'em slicks.
3. Limit wing size dramatically.
3. Mandate a completely flat bottom from nose to tail (no splitters, diffusers or venturis).
4. Raise them off the ground just a little bit.
5. Shake well.

[MattPete]

Quote

Originally posted by Ali_G
Ban all undercar downforce making parts.

Niall

I disagree with that, but more on that in a second.

One way to take a look at aerodynamics is to look at other series, such as CART, which have similar, but different, cars. Some people have done this, but I think some have them have drawn the wrong conclusions.

A good situation to look at are the oval races. Oval tracks have both long straight away and long sweeping turns, and allow us to look at aerodynamics in simpler situations. If you watch CART for a while, the first thing you'll notice is that the turbulance coming off the leading car has costs and benefits depending where they are on the track.

In the straights, the following car can use the hole punched through the area to slipstream/slingshot past. That's nothing new.

So what happens in the corners? In the corner, the turbulant air decreases downforce, which lowers the cornering grip of the following car. There are two reasons that this doesn't affect CART cars on the ovals as much as F1 cars on road courses: (1) Ovals have different lines, and the following driver can drive off line to get clear air over the front wings while cornering, and (2) underbody aerodynamics.

Champcars can still suffer from turbulance -- witness Fernandez crash at Michigan 2 years ago, when the turbulance from Tracy's car reportedly washed out his front end.

However, the reason they are less affected than F1 cars is because of their underbody aerodynamics. The sidepod tunnels not only produce downforce with little drag, but they are also less affected by turbulance. In addition, they also contribute to front end downforce. So if a Champcar loses half the downforce from the front wings, it's not that big of a deal because the sidepods are still providing some downforce on the front.

If an F1 car loses half of it's downforce on the front wings, it loses nearly half of it's front downforce (or at least closer to half than a Champcar). Sure, the flatbottom does provide some downforce, but it's got to be much less than a Champcar's tunnels. In addition, I would bet that the flat bottom would be a lot more suseptible [sp] to turbulance than the Champcar tunnels.

Of course, I could be completely wrong.

[Bex37]

As my signature has said for twelve months, impose control wings on the cars on front and back. The wings would be a standard design which are big, create high drag and very little downforce. The main purpose of the rear wing would be for sponsor signage!

The result is that there would be a big hole in the air to allow slipstreaming. Also the lack of any real downforce would mean that turbulence from a car in front would make no difference to the following car's corner speed. This adds up to the car following having a big advantage, even if it is much less powerful.

Further, since it is low downforce and high drag, it would reduce both top speeds and corner speeds. Isn't that what the FIA have been trying to do for the last 5 years without significant success? Even the FIA could predict the top speed of the cars knowing the drag and horsepower. If they are going to fast down the straight, give them a bigger wing with even more drag.

Once you've got the control wing, you can take away those stupid grooved tyres and they could race once again on real racing tyres.

[Isamu]

Control Wings would be GOOD.

That way engine grunt would be a lot easier to visualise.

As it is now u can't really tell a big difference in engines. It's all mostly aero which is ok but not as good as ENGINE GRUNT


:smoking:

[Darren Galpin]

Lowering the front wing makes it more efficient, as it then cleans up the air going beneath the car, and makes the car more sensitive to what happens at the front. Thus following a car around a corner is more difficult. Desmo is right - raising the front wing (making it less critical and less efficient) and better tyres this year mean that cars can follow each other more closely, and we will have more overtaking this year. Why not just give the cars the wings from a Formula Renault and have done with it? MattPete - well written piece.

[MrAerodynamicist]

Lower front wings are more efficient as it has strong ground effects. The closer to the ground a wing is, the more the airflow is restricted from going under the wing and more has to flow over the wing. Hence this increases the pressure above, decreases the pressure below and you get more downforce. Can't comment on if it tidies up the flow under the car nor not.

I'm with Desmo & co on this one - Turbulence does hunder passing. Turbulence affects following cars in different ways though corners and down straights and F1 has gone the wrong route with both!

[Manson]

Quote

Originally posted by Ali_G

Remember the 80's. All of the passing.

Niall

I think part of this was due to the wider cars and the wider tires. The rears were reduced in size at some point (can't remember the year). The big rears produced lots of grip but lots of drag also. Now you've got a lose/lose situation for slipstreaming. Less turbulence and drag off the leading car coupled with increased straightline speed (less time on the straights to grab a tow) from the aforementioned drag reduction. I think increasing the drag is the answer to more slipstreaming. Of course some purist don't like the idea of a drafting show.

[Amadeus]

So many points so little time!!!!!

1st - if I want to waych simplistic 'drafting' passing I'll watch CART (or the M25 on a clear day). I want to see drivers with ability attempting to pass each other. It's the old Basketball vs Football argument - basketball is 88-102, so each point is maningless and only the last seconds count. Footie has fewer scores, so they matter more - likewise in F1 - making overtaking difficult makes the passes that happen exciting - I have fallen asleep during NASCAR and CART races, never in an F1 race.

2nd - how can anyone with eyes say that a car with a huge dependenace on aero grip isn't disturbed by the turbulance of the car in front? Why are we debating the point???!!! It is obvious, and lets be honest, we may not like Martin Brundle, but the man does have a shrewd idea of what's what.

3rd - Every moron (apart from Max) knows that moving the balance back towards mech in the aero:mech equastion will result in better (not just more) passing and safer cars

meaningless threads......how much more work could I get done if not for meaningless threads

[Ali_G]

Right the following points are my guide to the FIA to help with passing.



1. Ban Barge Boards. These help stop turulence off of the fron ttyres and also help to push air around the sidepods more effectively. If these were banned teh car would produce more drag.

2. Limit the angle of attack that a team can use on the rear wing. Say that all elements can only run to about 10 degrees.

3. Limitless elements in rear wing in corespondance with my seond part of advice.

4. Raise the rear wing to its former height before 1995. This would add more drag.

5. Ban all splitters and diffusers. Put a rule in saying that the lenght of the car must be flat.

6. Re-intorduce slick tyres. There would also be widertyres to make up for the loss in aero grip and to add drag.

7. Put a limit on the height of tyres. ie: That they will have to be a certain height. This will also add to drag.

8. Raise the weight limit to 650 KG. At present it is 600. Slower braking and accel should help with passing. (note Yo_yo Effect)

9. Ban carbon braking and put a limit on the size of the braking disc. Say that it has to be larger than the present limit.

10. Widen the cars again. Have the external chassis dimensions increased to 2.2 meters but do not widen parameters of wings.

11. Have it so that all tyres must be outside of the external chassis. This would add drag even further and of course the cars would be more stable.

12. Put a limit on the lenght of cars. The shorter they are mena the more drag they will produce.



Niall

[Ali_G]

So what do ye guys think of my proposals.

Niall

[unrepentant lurker]

You seem to be on a drag kick this week.

1. I'm not entirely sure on this, but... I thought the purpose of barge boards was to improve airflow to the difuser. In doing this it produces more drag. So you sacrifice speed for driveability. There is the RS/Head anecdote(sp?) after the loss of the bargeboard. Head: Lap times were the same. RS: That's all fine, but the thing was impossible to drive.
Reguardless, it goes along with point 5 anyway.

2&3. Sure, you hang a drag shute on the back of the car, but you will swing the aero/mech pendulum way back to aero - which you don't want.

4. Same as 2&3.

7. Seems like this is done already. I know the FIA has clear regs on what tires you can run. I think the teams will always run as big as they can.

8. You are making crashes more dangerous. I thought we put your yo-yo garbage to bed months ago.

9. Larger brake discs will be more efficient brakes. Anyway, braking distances are determined by tire grip and not the braking power.

12. Your up against a wall here. I think that the cars are as short as they can be currently. The reg requiring the drivers feet to be behind the front axle mean to shorten the car the driver would have to sit more upright (bad for cg).

Anyway, all of your points taken as a whole look a bit like some sort of formula NASCAR. Speaking of which, I watched parts of a NASCAR road race last August, and I didn't see any passing there either. That despite all of the drafting, manual gearboxes, lowtech spec whatever and full course yellows every 10 laps.

[Ali_G]

Just to say that the Yo_yo effect does exist. This was backed u I think by Dave Martin who said that James hunt said it existed and explained it better than I ever could.

Niall

[FerrariFanInTexas]

Let me add a different note here: Haven't the changes to the TRACKS also contributed significantly to the processional racing we've witnessed the past ten years?

Every track that used to have long straights where drafting and slipstreaming might actually work now has an odd and unattractive assembalge of short straights and chicanes. The newest track, Indy, has an enormous straight with lots of room, and suddenly people could pass again.

More open tracks also allowed the teams with better engines to power past the chaff. Even with the long straight at Indy, MH couldn't pass a Minardi for what, five laps at Indy last year? The tight infield portion made him adopt a car set-up that couldn't take advantage of the slipstreaming opportunities the long straight and his more powerful Merc/Ilmor engine should have allowed.

Because of that, I'm sure the aero/mechanical grip issue plays into this directly, but it seems that the process of getting rid of longer straights and making the courses a bunch of short straights and sharp turns coincides with the lack of passing. I don't recall a lot of passing going on at the chicanes (except maybe Bustop at Spa), so I don't think you can argue that more turns provide more passing opportunities. Also, while I know the reason for changing the courses is to increase driver safety, as I recall the drivers were none too happy with the bastardization of Monza last year.

Maybe some of you Technical Forum-types can explain in fairly simple "lawyer-understandable" terms how the new "safer" course design plays into the passing issue.



Avanti Ferrari!

[Ali_G]

I personnally don't believe that its the circuits at all.

Back in the late 80's there was loads of passing. But all of the tracks were basically the same.

Hockenheim was the same, as was Monza and a number of other tracks.

Its just that the cars are now too aero efficient with the intordction of Under body downforce generation and barge boards.

Niall