F1 car vs LMP1 car - downforce levels

[Alastor]

The limit depends no just on the 'g' level but also the duration. The human body can survive higher g levels if the duration is shorter. That is why race car drivers can survive crashes where the peak g’s approaches a 100 g.

In the case of driving a car I would also guess that not only the duration of the acceleration would matter but also how long you have to recover between each corner.

[Matra et Alpine]

Commodore, I thnk the ground force, skirted cars were some of the prettiest and quite "clean".

In the real groudn effect days with side skirts then there was no need for any "clever" stuff, keeping the air flow clean over the top and clean underneath with the moveable side skirts gave HUGE forces

eg RE-20, BT-49

[Commodore GS/E]

ooops...i may have confused those with the winglets of the noughties... it may be a question of different tastes, but i really think all those little wings look ugly on that car.

[culver]

I definitely think the ground effects cars would be better looking. Look at the Champ cars from the early 1990s. They were high downforce and looked very clean. I think cars like the Penske PC17, PC21 and PC23 were some of the best looking modern race cars (F1 of the same time also had some great lookers).

[TheScrutineer]

This may be foolish...but isn't the maximum horizontal g a trained man could take around 40 g? Vertigal g is lower (14 g), maybe you confused that.

I am pretty positive it was some stupid figure that the human body could not handle lap after lap, I remember that paragraph quite vividly. Maybe they were referring to dropping the regulation tyres and putting slicks on? Saying that I was a complete stoner during this era so...

On the point of ground affect, can I ask... If F1 was to go 'ground affect' and drop big wings would we still get the same amount of 'dirty air' causing overtaking problems? I used to think no, but after reading a bit about diffusers and the dirty air from that I am not sure if I have been right to assume this?

[Matra et Alpine]

Commodore .... agreed, the winglet and add-on era was UGLY.

Scrutineer ... interesting Q. I reckon it would be possibly "cleaner" and also have less impact. The moveable side skirts pretty much allowed the front to "scoop" oodles of air and with having no "spill" the skirt cars would have less vortices and shitty air bleeding.

BUT, the exit from the rear coudl cause a massive area of very low pressure immediately behind the ar and potentially an area of pressure waves behind. Balancing that though I think the aero guys woudl be able to manage much cleaner "release" of the air pressure (negative) and possibly much MUCH cleaner. Without having to have big wings and wing elements then much less dirty air around.

Of course, we forget the problem THEN would be as it was then leading to bans ..... road surface, kerbs all leading to MASSIVE reduction if hit and in corner downforce going to 1G from LOTS-G very dangerous. ON top of that the moveable skirst wearing, sticking and in themselves wearing the track sruface were all contributory factors to their removal. We'll never see them back and thankful for that too. Those days were like watching Scalextric cars at times as they jsut always turned in and went round as if in a slot.

[TheScrutineer]

Of course, we forget the problem THEN would be as it was then leading to bans ..... road surface, kerbs all leading to MASSIVE reduction if hit and in corner downforce going to 1G from LOTS-G very dangerous. ON top of that the moveable skirst wearing, sticking and in themselves wearing the track sruface were all contributory factors to their removal. We'll never see them back and thankful for that too. Those days were like watching Scalextric cars at times as they jsut always turned in and went round as if in a slot.

Cheers for the info.

I understand the problem with 'stalling' when bottoming out. I read an interesting article in Autosport saying that the secret to Redbull's success is probably not ride height control, that because of their 'pullrod' rear suspension the diffuser is more simpler and less prone to stalling than other teams.

The thing is, ignoring this problem I think the boffins in F1 could develop a form of ground effect that is tuned for less dirty air and is restricted slightly to stop high cornering speeds. That will cost a lot to develop though I suppose.

[Matra et Alpine]

^ Kind of where we are
By banning side skirts then it's a more controllable "form of ground effect" ... but of course F1 designers being what they are will then take what they have to an extreme for a miniscule advantage and then screw the "racing" for us

[RacingManiac]

Cheers for the info.

I understand the problem with 'stalling' when bottoming out. I read an interesting article in Autosport saying that the secret to Redbull's success is probably not ride height control, that because of their 'pullrod' rear suspension the diffuser is more simpler and less prone to stalling than other teams.

Sounds like BS to me. The Pull or push rod the function is the same, and if anything pull rod takes up more real estate around where the diffuser sits. Journalists are just that, they look stuff to report where there was none. Same people also said Newey had a harder time to package double diffuser last year because of the same suspension....

Thats off topic though...


Its not just the wake thats making the car hard to follow though. Wings(in their various guise on a modern F1 car) needs clean flow to function, where as tunnel is less sensitive to flow. And with F1 car's grip is dependent on wings effectiveness(both front and rear), as soon as the air becomes turbulent the front wing becomes less effective, while the the rear may still be functioning ok due to the help of still-present ground effect and rear wing, the front is not, thus understeer becomes a problem and you are less able to follow the speed the car infront of you can do. On a tunnel car that is less of an issue as primarily the downforce comes from the tunnels, which I'd imagine sets the center of pressure closer to the CG(will shift as the car pitch and dive, biasing downforce distribution fore and aft).

I think going all out with skirts and such is not the answer simply because of the same reason they were banned. But looking at the current crop of LMP car with a fairly effective(yet is a spec design) tunnel, I think something akin to that approach might be good for F1...

[Matra et Alpine]

RM I don't see the conflict with last year the suspension being difficult for double diffuser and this season that it is simpler. Was that what you were proposing ?

Until you see WHERE they have located the pivot points and components and the angles and lengths for this year then we can't refute any claim that location matters
Same with pull rods One design doesn't mean others dont' exist or work.
WHich ones are you comparing ??

Was interesting to see the efforts RB team were going to so Brundle and the BBC grid crew could not see the rear suspension. Even "tempting" him to look at one point

[RacingManiac]

RBR(and by extension, STR) ran pull rod both 2009 and 2010. Lots of speculation from the same F1 journalist circus who claimed that RBR was late in showing up with DDD was due to the pullrod being obstructive to packaging DDD(due to the need for extra volume near the rear around where the gearbox sits, and where Pullrod also sits, as well as the bits under the gearbox). And the same people who claim before RB6 was shown that the 2010 car will not have pullrod due to the need to have an optimized chassis for DDD packaging. And now the same people(probably not the same people, but I am talking about F1 press in general) are saying that the same design that supposedly made their packaging more difficult is now making it simpler? I have designed FSAE suspension using both, and we have no aero. But you can make cases for both knowing how it needs to work. I thought the pullrod will make DDD more difficult to work KNOWING that when Adrian Newey designed the 2009 car without considering the need for such device(thus no provision was made in the design), but no reason he can't move the points around to make DDD work with pull rod. But the same case can just as easily be made the other way around.

Of course I know the ins and outs of how you can design the same bits differently. But F1 press likes to a)over simplify stuff they barely understand, then b)super sensationalize it by making baseless claim.

Again, a bit of off topic though...

[Matra et Alpine]

"Knowing how it needs to work" ... key point.
What you say is as valid as the F1 press comments.
"Possibly" true
As stated, comparisons without knowng all the variables are impossible.
AND we are talking about a DIFFERENT tub and upper body aero package thus the CG of the aero may be entoriely different requiring radically different airflow.

I'm not questioning your FASE experience.
Only pointing out that based on over 35 years of suspension setup for race/rally in many different chassis and teams it's NEVER as simple as it seems on any angle

It's the role of a journalist to present what little info they can find out and add conjecture --a s long as they dont' state it as fact. We have to live with that
Kind of the same way as engineers that we realise we can't make assumptions.

[RacingManiac]

Thats basically what I am saying, but having not read the original article, and reading the paraphrased quote as quoted from TheScrutineer's post, they might as well replaced that

"...the secret to Redbull's success is probably not ride height control, that because of their 'pullrod' rear suspension the diffuser is more simpler and less prone to stalling than other teams. "

with

".....the secret to Redbull's success is probably not ride height control, that because of their magical pixie dust the diffuser is more simpler and less prone to stalling than other teams. "

No more or less valid or having more or less information....

Personally, if Autosport has headline of "Redbull's Magic Pixie Dust Suspension is their secret to success" will probably sell more paper...

Besides, the did say prevent the diffusion from stalling, which is implying somehow that pullrod can deal with ride differently than pushrod, since for both, under the rule, can't be manipulating the aero components directly(can however, influence it through ride of the vehicle), which IS utter BS since there is NOTHING that you can do with pullrod that you can't with pushrod, given free reign on kinematics and placement as F1 cars are given.

Still OT, I know...

[TheScrutineer]

Mark Hughes is the guy, and he is pretty well respected and he seems knowledgeable. This below is not the article (I will have a look tonight) but some of his writing on the redbull Pullrod:

“But there’s compromise to be drawn in virtually every design decision of an F1 car and this is clearly where Newey’s team feel the optimum solution lies. The most radical aspect of the car is its pullrod rear suspension. Every other F1 car has pushrod rear suspension and has had for the last couple of decades. But Newey has reasoned that with upper body downforce so reduced – and the underbody downforce enhanced – by the new regulations, the point of compromise has changed. The pullrod layout allows the rocker that operates the spring to be sited much lower and there are none of the lumps and bumps in the bodywork seen on other cars needed to clear the upper rockers of the conventional pushrod layout. It has led to an incredibly tightly packaged rear end, leaving a massive space to channel airflow to the rear beam wing. The regulation rearward shift of the diffuser has created the room to do this, though the siting of lower rockers will have compromised the shape of the diffuser. An additional benefit of the pullrod layout is its lower centre of gravity.”

[Matra et Alpine]

Besides, the did say prevent the diffusion from stalling, which is implying somehow that pullrod can deal with ride differently than pushrod

Aha, now you se that's not how I read it and maybe this is a classic English-English versus american-grammar-meaning ?

I read that he was saying that because of the magic pixie dust the aero package meant it was less susceptible. Thus the suspension components arent' in the way of what they are doing underneath on aero.

They are where they are because it's RBs pullrod design.
If they had a pushrod design that resulted in the same benefits then that woudl also be true. IFF the suspension allowed the aero difference.

I sense you were reading a more "direct" influence, that I certainily dont' take from the words used.

utter BS since there is NOTHING that you can do with pullrod that you can't with pushrod, given free reign on kinematics and placement as F1 cars are given.

ONLY if you look at suspension in isolation.
Component placement differs in each.
So I refer back to what I was saying about each arm length and angle makes a huge variation in the physical packaging and influence in any pu**rod design.

I tihnk we've jsut hit one of those "common language" problems and as "native" readers we're not taking it the same way and causing the difference in interpretation. Hope so, as that's an even better excuse for the differences raised