Mercedes GP MGP W01

[mep]

This f-duct discussion keeps flaming up from time to time.

One thing I have in mind for a couple of days now:
It is said that McLaren tested the f-duct first time around Monaco GP 2009. During that time the switch over from Mercedes to Brawn GP was not in sight yet. McLaren was able to keep the f-duct very well hidden from the other teams and was able to surprise them in the beginning of 2010 season.
Now I wonder if they where also able to keep this system hidden within the same team. Some guys of Mercedes must have noticed that something is going on there especially because the system takes a significant amount of air volume from the engine. A reduced airbox size will raise questions. There are also guys in charge of actions. Yes Norbert Haug is not a technician and some of the other responsible persons there aren’t either but I think they should at least be aware of some things and give their blossom to it. Remember Mercedes was a big shareholder of McLaren they should be informed about the things going on there otherwise it is no surprise they did split up and creat their own team.

What I want to say by this is that I start to get the feeling that they actually did know about the f-duct long before any other team noticed anything. Think about the double deck diffuser and how the knowledge spread over some teams. I think in this case things went different. Mercedes is not a nameless employee that can walk out of a team with the latest Know How. Due to some contracts, how ever they might look like, it was not allowed for them to steal the idea.

Having that in mind and looking at the car it starts to look different. They actually did develop a car with a f-duct in mind. This very low airbox was made to put a f-duct on top of it. With this they would have the best f-duct of the field. Unfortunately they had to pull the plug of the design in the last minute. I guess they could not solve the conflict with McLaren and therefore end up with a half finished car. To much drag on the rear, misbalance of front wing, wrong weight balance etc...

The only solution they had is to make their own design which was different of the McLaren initial idea. That’s why they are the only car which has a very strange and inefficient f-duct even after their car would have been the best one to put on a f-duct.

[747heavy]

interesting theory Mep.

I think what McLaren has used in Monaco 2009 is a bit different to their current F-duct.
As there was no "shark fin" engine cover, and no connection from the airbox to the rear wing in 2009.
Funny enough, their rear wing in Monaco (similar to what Sauber used) is closer in principle to what MGP is using now.

Why I can follow your reasoning, it would/should still be possible to copy the system after McLaren has "shown it off", most other teams in pitlane just jumped onto the band wagon and had little qualms to copy it, as good as they could (with the limits of the homologated tub).

Another interesting observation from the Suzuka GP is/was that M.S. was the fastest car through the speed traps, and the fastest (top speed) in the first and second sector as well as 2nd in the 3rd sector.

http://fialive.fiacommunications.com/en ... e-trap.pdf
http://fialive.fiacommunications.com/en ... speeds.pdf

[lolzi]

Another interesting observation from the Suzuka GP is/was that M.S. was the fastest car through the speed traps, and the fastest (top speed) in the first and second sector as well as 2nd in the 3rd sector.

Looking at the time of day at the speedtraps, Rosberg and Schumacher was timed inside a second of each other as far as I can see. Because of that, I think Schumacher might have been slipstreaming Rosberg which would give "false" numbers.

[NewtonMeter]

Hmmm guys I do not follow completely here.
we have heard about the weight distribution issue but in the end it seems very unlikely that they were unable to shift enough weight -the only sound explanation would be ballast part of the homologated structure and not movable...seems not very likely .
So we come back to aero issues or a stiffness issue in their chassis .With them
being so quick on the straigt in Monza ..my guess is they underestimated the required stiffness for their chassis.
That in itself would not require to scrap the whole car concept.
Also we have to see that with kers the rearward weight bias might be inevitrable so any weight you might have had in excess at the front might be an advantage in 2011...After all Mercedes has the best starting point in their KERS ,where only Macs is in a better situation with actually having packaging and running experience with this very unit from 2009...RedBull has to hope for Renault having improved their system to the Mercedes level.And Ferraris unit (similar to Renault )was not really the hot ticket.
And of course you learn every time you go out .The point for Schumacher is:Not to go out with risky parts ,better make the most out of what you have in terms of proven components.And introduce new bits on friday and campaign them in the race when you are on top of them in terms of speed and reliability.
I feel the teams do not the best job with new parts,sending out both cars with the same parts.To me Friday FP has to be car 1 baseline normal programme ,car two development parts.This way around one of the two heros will work on optimisation ,the other is working on the future.and still has Saturday to adapt to the proper race car.

I think it's important to note that the weight distribution issue has many other repercussions. Yes, ofcourse they can simply add more weight here or there. The thing is, the weight distribution and "downforce distribution" (aero balance basically) needs to be within certain limits of each other otherwise the car will become unstable during heavy maneuvering.

So sure, they can change the weight distribution for the optimum tyre performance, but they can't change the aerodynamics correspondingly because that might lead to any number of aero related problems.

So what they are racing with, is a severe compromise. They really are between a rock and a hard place.

To add insult to injury, they can't do much about it because of the double whammy homologation rules and testing ban. So MGP are fighting this years championship with not even one, but BOTH hands behind their backs.

If anything, they should be applauded for their efforts considering the circumstances. Just my opinion though...

[JohnsonsEvilTwin]

For the benefit of the thread, I will quote Scarbs analysis of the W01.

Even from the cars early days in testing, Mercedes have had problems with the MGP W01 and Ross Brawn himself has been candid with the cars problems. Fundamentally the car has the wrong weight\aero bias, with it being too far to the front. Last year one of Brawns strengths was its extreme forward weight bias, typified by the large slab of ballast in the front splitter, when the wider front slicks rewarded a +49% bias towards the front. This year the tyres changed, the front tyres being 25mm narrower with a 20mm narrower tread, the rear tyres were also stiffened to cope with the heavy fuel loads. Most teams perceived the loss of grip from the rear tyre change would not offset to loss in front end grip from the narrower front tyre. Perhaps Mercedes (nee Brawn) felt the tyres would still favour a high percentage of weight towards the front, indeed the car still sports a significant slab of ballast in the front splitter. At the last race the cars inherent weaknesses were exhibited by Michael Schumacher, who had both understeer and a chronic lack of rear grip, leading to poor traction in the wet and overwork rear tyres in the dry. In Schumacher’s case his driving style tends to favour oversteer, while Rosberg is able to better cope with lack of turn-in and understeer the Bridgestone’s provide. This trait of the Bridgestone front tyres has been present since the shift to a single tyre supply, which has only worsened with the move to slicks and now narrower slicks.

Tyres work within a window of ideal vertical load. This load comes from weight distribution and downforce, simplistically the former affects low speed grip and the latter higher speed grip. Teams need to balance the static weight distribution and downforce front to rear to suit the tyres. A graph of load versus grip for a tyre will see significant drops either end of the scale as the tyre fails to work when either over or under loaded. It seem that Mercedes have too much load on the front tyres which will see them give up grip as the tyres gets too heavily loaded, this induces understeer. Conversely they have too little load at the rear which will compromise traction off the line and out of slow turns, but also induce oversteer. Having both ends of the car with incorrectly loaded tyres loads, will produce a car lacking in balance. The team could reduce grip at the rear to balance the car, but will then have a car lacking in grip.

Although drivers favour certain degrees of understeer or oversteer depending on their driving style, both prefer this to with consistent balance and grip. The differences in car set up between drivers are very subtle, its unlikely that one driver will have a significantly different weight\aero balance front to rear compared to another, certainly not to the level where one driver runs a different layout or wheelbase. the changes will be in small differences to; suspension, wing angle and\or ballast placement.

In Mercedes case, they have tried to shift weight rearwards; this is limited by the team’s ability to find areas to house the slabs of tungsten\densamet within the tight confines of the gearbox. An area now compromised due to the packaging of the double diffuser. To shift weight distribution 1% needs a shift of 10Kg from one axle to the other, obviously space at the axle line is limited, and so potential a greater weight within the wheelbase may be needed to achieve the same effect.

If ballast placement is not going to do the trick, which appears to be the case with the W01. Then the team are facing a layout change. Which means the front and\or rear axles will need to be shifted forwards relative to the chassis. Something that could be done either by new front suspension moving the front wheels forward, or the same at the rear. The rear option could also be achieved with a shorter gearbox. Gearbox lengths have extended in previous years to push weight forwards, thus there is scope to reduce their length without having to resort to all new gear and internals.

According to the informed rumours, Mercedes will opt for a blend of front suspension changes mated to a shorter gearbox. In the process extending the wheelbase. Many in the media have highlighted the changes as a wheelbase change as the solution to the balance problem, but the extended wheel base is largely a function of the shifting the axles. It is not in itself the primary solution to their problems.

Shifting weight also demands a shift in aero balance, for Mercedes this means more rear downforce. this cannot come purely from more rear wing angle as the drag that produces will slow straight lien speeds. So ideally greater diffuser development is needed. the team have been quick to get a passive F-duct running, this will certainly aid the ability to run more rear end downforce, but they must be careful its benefit is not eaten up by the need to run more rear wing or sales they will lose the advantage it gives other teams.

It now transpires that the F-duct rear wing on the W01 in China was passive device. There remains the development of the ducting towards the cockpit and a tip-off suggests this is tied to a reshape of the roll structure. How the ducting then reaches the rear wing may be either via a shark fin or up through the rear wing support. Although Brawn tested a sharkfin briefly in 2009 on the BGP001, the team have yet to race a version of it, making them somewhat behind the times and lacking experience in how the taller bodywork reacts on track.

At least one area not a concern for the team will be their mirrors, which are already cockpit mounted and not subject to the repositioning facing some of their rivals (RBR & Ferrari).

We can expect a very different W01 to appear for the next race, we will cover the developments as soon as the car breaks cover in the days preceding the race.

[mx_tifoso]

You couldn't just post a link?

What's the point in making such a dramatic suspension and gearbox change so late in the season? It's a pretty big gamble and chances are that it won't pay off, especially at a circuit where there is no past experience or data to rely on.

And how will the wheelbase be extended if the gearbox casing is shortened? Will the suspension change more than make up for that or was it a typo?

[feynman]

That quoted scarbs text is from April ... "next race" doesn't mean Korea, those modifications have already long since transpired.

[mx_tifoso]

I see.

No wonder I was doubting whether they would do this twice in a season.

[JohnsonsEvilTwin]

Sorry Mx, it is a wall of text I agree.

feynman,

Yes that is true. It is from the Spanish GP so from May onwards. The problems are still there though, so its just to give an understanding. The problems arent easily solvable when you mess up the way they did.

[marcush.]

tbh the shorter gearbox story got me thinking:
On one hand they do not find space to mount 10kg of tungsten inside the gearbox bellhousing ...think of a piece of 10ox100x28mm ....but on the other hand there is scope to shorten the gearbox housing to accomodate a shorter wheelbase moving mass rearwards...something is not fitting there..
You could quite easily mold a piece of tungsten(or densimet or whatever alloy they use) to be mated into the available space within the bellhousing then.
But as I understand the wheelbase shortening(by gearbox housing redeign) was for whatever reason cancelled...hinting at them realising they were hunting the wrong rabbit till Barcelona ,perhaps? And tbh where was the Merc competitive? Bad weather conditions,Monaco and in low grip situations (green track) So 747s theory (?) with the chassis stiffness issue has a point.

ONE important question: Would they be allowed to run a unhomologated W01b Tub in these three end of year testdays?
If they really know what their problem is ,why not beef up the chassis to check what they left on the table due to this majaor mishap..just an idea .What is the penalty for driving an unhomologated tub in a test session anyways?

[747heavy]

you make a good/interesting point, Marcus - IMHO
I don´t think there would be a problem in running an unhomologated chassis, but I could be wrong. Maybe they would be forced to crash test it for safety reasons.
Other then that, I can´t see too many problems doing it, and I would think it´s worthwhile to do so. (but I don´t know for sure, just my opinion)
Maybe we see some teams running an interrims car, possibly with single diffusor and without F-duct. Not sure what FOTA/FIA/PIRELLI have agreed for the tests.

Seeing that Lotus and Cosworth terminating their contract after the last race, maybe there is a chance we see a Lotus with and Renault Engine at one of these tests. Not sure we will, just a thought.

[marcush.]

If that was feasible ,I for sure would do this and if this was feasible compare with a std chassis with a back to back test.
If you are only allowed to campaign one tub ..it would of course necesitate a field imple´mentable solution ,but still a possibility...
And I think this would be the best solution anyways as I think nobody will scrutineer a tub twice a day...and you could hide your work a lot better stating you found something by putting on some new front wing or an improved floor design..
Just imagine you suddenly find the missing second.We will have to monitor MS and RBs faces during testing on these days very closely ..thats my guess.

[mep]

Has anybody read my above post
I expect some reactions on this.
When I write Alonso is a cheater I cause several pages of reactions and that even is a proven fact.

[747heavy]

sure mep. even commented on it.

[mep]

Yes and thanks for it but you are the only one.
I always think there is some secret agreement not to react on my posts.
Seems like this society has not contacted you yet.