High Nose cars fastest at SPA... Why?

[ISLAMATRON]

FIF1 surprisingly fast, Ferrari showing the best they have all season, BMW doing well in the middle of a terrible season and Red Bull reverting to their early season high slim nose... is the speed of the high/thin nose cars at SPA a coincidence?

Is there a proper explanation that the aero experts on here can provide for us?

And will it be similar at Monza?

[Scotracer]

Correlation doesn't imply causation.



That's the Sector 1 Speeds from Qualifying.

So we have the Ferrari, Force India and BMW all topping the speeds (however the Ferrari does have KERS...). I didn't use the Speed Trap results as they are at the top of Raidillon so not fully representative of the car's ultimate speed.

The Force India's have been fastest in the Speed Traps all year. The BMW's haven't really been at the top of the speed trap this year. I don't know if there's something in it but maybe we'll find out at Spa if more people go for a straighter nose.

[vasia]

Actually this isn't entirely correct. Badoer was very fast in the speed trap, but had useless actual race pace. FI most of the year topped the speed traps, and backed it up with useless race pace.

Just a clarification, Red Bull, Force India and Toyota are the cars that had the slimmest noses which were also high nose cars. The Ferrari is a medium height slim nose car, and the BMW is a wider nose car with a medium height.

The reason BMW and FI did so uncharacteristically well is because their cars are probably good in a low downforce configuration.

[xpensive]

A speed difference, for two identical cars, from 326 to 328 km/h correlates to roughly 13 Hp, when based on 700.

I wonder how much flat-out power can differ between today's engines, say between a Mercedes and a Toyota?

[ISLAMATRON]

Badoer was super fast thru the trap because he had no ideas to brake for the next corner... it will do wonders for trap speeds.

Red Bull did switch noses, that should tell us something... the only team I could see changing nose types for Monza is McLaren(and STR since they still have the old ones in the shed), the rest pretty much lack the resources or willingness.

xpensive; that could be the difference between a fresh lump and a used one of the same maker.

[Ray]

Actually this isn't entirely correct. Badoer was very fast in the speed trap, but had useless actual race pace. FI most of the year topped the speed traps, and backed it up with useless race pace.

Just a clarification, Red Bull, Force India and Toyota are the cars that had the slimmest noses which were also high nose cars. The Ferrari is a medium height slim nose car, and the BMW is a wider nose car with a medium height.

The reason BMW and FI did so uncharacteristically well is because their cars are probably good in a low downforce configuration.

Kubica claims that the BMW is good in low downforce configs. We'll see in Monza. I hope they are, maybe they'll end the final season with a bang that doesn't come from the engine.

[xpensive]

A speed difference, for two identical cars, from 326 to 328 km/h correlates to roughly 13 Hp, or two percent, when based on 700 Hp.

I wonder how much flat-out power can differ between today's engines, say between a Mercedes and a Toyota?

But obviously, if the same car can decrease it's cross-section area with the same two percent, still with the same Cv, speed will also jump from 326 to 328 km/h.

This is why I wonder about the Cv of the rear wing, when a Monza-style such seems to yield more speed than the reduction of cross-section suggests? In other words, how big is the difference in rear-wing Cv from track to track?

[Fil]

Peter Windsor was saying during the weekend that in layman terms, at initial design desicions teams decide whether they aim for a car strong at generating high downforce, or a car strong at aero efficiency.

The aero efficient cars were the ones shown to be strong at lower downforce tracks such as Spa, and soon Monza.

[xpensive]

I seriously doubt if Windsor knows much more about F1 engineering than Flavio?

Anyway:
So top speed at Spa was 328 km/h, that's 204 mph for you with English as your mother-tongue, by Adrian Sutil.

Given this is achieved with 530 kW (720 Hp), imagine that we add 60 kW KERS to that, speed would only jump to 340 km/h.

An xtra 12 km/h for 80 Hp, at these speeds you don't get much bang for the buck.

[megz]

Probably not even that given that aerodynamic drag increases exponentially to speed...

[xpensive]

No, exactly the above. Power has a cubic relation to speed.

[megz]

Ah apologies, forgive my ignorance.

[xpensive]

Not at all, I should have xplained what I did above;

(340/328)^3 = 1.114

1.114 * 720Hp = 800Hp

The difference in power is the 80Hp from KERS.

[BreezyRacer]

Red Bull did switch noses, that should tell us something... the only team I could see changing nose types for Monza is McLaren(and STR since they still have the old ones in the shed), the rest pretty much lack the resources or willingness.

To me this is really the interesting question .. the Red Bull nose change. I don't think they even appeared with it until Saturday for Qualli. Maybe they tested it in the P3 session. I don't know 'cause it's not televised here in the states.

I'm thinking they had more front DF than they needed so they may have elected to leave the wing alone, with the new flick ups, and reduce drag by going to the original nose. I'll just add that for a team that has Newey in their back pocket they haven't changed or tried too much lately. Maybe Horner and company got a little cocky??? OTOH, the Renault engine thing has left them maybe a bit off pace on these motor tracks, including the upcoming Monza.

I'm also wondering if the ultra low rear end is killing some of the possible benefits of a double decker diffuser design. They just aren't leaving as much of a wake as the other cars produce. I would like to see what the car would do if they were to stand up the lower wing element some more, or maybe even change it's mount height. They might find a more efficient diffuser package that way. Hey, I know you read these posts Newey .. get on it!!!

[PNSD]

In 2004 Mclaren turned up to Monza with a much fatter nose than the original on the 19B