Red Bull RB7 Renault

[hardingfv32]

Is there any chance that road car rake is all about styling or aero drag/fuel milage?

Brian

[Owen.C93]

You can't really measure rake on a car from a photo since you can't see the chassis. It could just have low body work on the front end etc. Luckily on F1 the floor has to be flat which helps.

[AbbaleRacing77]

AbbaleRacing77

Exactly how does the "super" diffuser use the exhaust flow to its benefit?

Brian

It uses the exhaust flow to create a much deeper/higher diffuser using the exhaust as an artificial barrier extending much lower to the track than what the regulations allow the actual diffuser extend to. The FIA only allows the diffuser to be confined to a very shallow dimension ( i dont know the dimensions off the top of my head) So lets say that the current diffuser is only 12cm high according to whatever the regulations are... the exhaust flow now extends the sides of the diffuser all the way to the ground/track adding additional volume to the diffuser as long as the exhaust is blowing through it.

I feel like this is hard to describe but im pretty sure that im onto somthing here. I think i need to photoshop a better graphic to describe this

[godlameroso]

Not only does it create a virtual skirt, the exhaust gases also increases the dynamic pressure over the diffuser, creating a bigger pressure gradient. I'm kind of bummed that they want to ban this, it's an area with a lot of development potential, in addition, aside from being somewhat time consuming, it's relatively a pretty cheap area to develop. I would have loved to see next years cars with the design optimized for their chariots.

[PlatinumZealot]

You can't really measure rake on a car from a photo since you can't see the chassis. It could just have low body work on the front end etc. Luckily on F1 the floor has to be flat which helps.

The M5 has a flat bottom made of plastic panels. It is interesting to me because not all supercars have a significant rake angle, some have leveled bottoms, like the Veyron. I guess it is just up to the designer of the car.

Here is a picture of the Mclaren 12C. It has some significant rake too.

[marcush.]

the bottom panels on modern production cars are for drag reduction and do not help downforce as I understand they even cause lift if i´m not totally wrong..rake or not.

[PlatinumZealot]

I disagree with that as the M5 doesn't have any wings so most of it's DF must come from it's front spliiter/floor combo. Yes the original purpose of the underbody panels was to reduce drag, but nowadays you can make significant down force from the floor on production cars, as seen on the Nissan GTR which makes about 180lbs of downforce at 180mph. The M5 makes good downforce too, Marcush.

But back to RedBull. I found this infographic on autosport forums, it mentions the pillars and the vortex that is made by the EBD:

[dren]

That's a good picture, explains everything well.

[AbbaleRacing77]

Heres what redbull is effectively doing to artificially create a diffuser thats almost twice as big as it should be. Ferrari and Mclaren are also effectively doing this yet they are still lacking downforce somewhere else. Ive already mentioned this before but the Red areas in the photo are the areas where the exhaust is getting blown in order to create a artificial barrier. This combined with super high rake creates one giant diffuser. Now... USUALLY general racing principals and common sense tells us that a high amount of rake is not beneficial because fundamentally you want the car to be designed and balanced with a rake that is level for CoG reasoning and a more harmonious suspension setup under motion changes. Normally a car with high rake like this is really badly design and using high rake to compensate for huge amounts of understeer but tends to be snappy mid corner. Red bull have designed there whole car around this super diffuser so that the car and aero are designed to be tilted way up in the air, making this whole crazy diffuser work well with there package. Kinda cool

I think BMW designs it's road cars with a heavy rake. Cadillac and Chevrolet as well. SO I guess those manaufacturers thought a COG raise of a cm or two is not so detrimental when you get such a benefit in high speed stability.




With a middle engine car the raise is COG height is gonna be a bit more as expected but hey Newey made it work! I want to see if this is the next "fad" for 2012.

First of all this has nothing to do with why the rb7 is running alot of rake.

And second no car designer designs there car with heavy rake.... Car designers design cars to be as well balanced as possible which is very hard to do when your designing something to be balanced at speed... Ive owned race cars that have had huge amounts of inherent understeer ( which i ran lots of rake to balance) and cars that are very well balanced (running minimal rake).

But... what im trying to get at here is that red bull is not running tons of rake to balance there car.... This is obvious because if they designed a car that was that far off balance wise they would not be dominating as they are... Their car was designed with this much rake from the get go for a very important reason... And that reason combined with an artificial skirt produced by exhaust gasses as shown in my edited photo is to increase the volume of there diffuser...

[spinmastermic]

Road cars are raked to account for extra loading. The rear axle takes most of the load from rear passengers and what goes in the boot/trunk. This has to be accounted for. Put 4 adults in that BMW and the rake angle will get smaller.

[marcush.]

How much ride height does the M5 have ?

I seriously doubt any of the clumsy diffusser thingies and underbody panelling has a countable positive effect on downforce.

but maybe someone can shed some numbers ...I have some Audi A8numbers but those are indicating that any of the downforce is derived from top body shaping(raising the bootlid for example and design separation areas at the rear quarter panels).

[Alexgtt]

It seems very logical to me that the increased rake makes the diffuser (actual and virtual) bigger in volume.

What's clever is that it's beautifully designed and integrated into the car from the drawing board and not easily replicated by the other teams until they design new cars.

[godlameroso]

That's a good picture, explains everything well.

It sounds like they're rehashing a watered down version of some of the conclusions we came up with in the EBD thread.

viewtopic.php?f=6&t=10098

[Owen.C93]

That fin infront of the rear tyres is new in that illustration. I can't imagine RB would tell him exactly what upgrades are coming.

[aral]

Road cars are raked to account for extra loading. The rear axle takes most of the load from rear passengers and what goes in the boot/trunk. This has to be accounted for. Put 4 adults in that BMW and the rake angle will get smaller.

Apart from that, designers automatically design in a lower stance at the front, as it makes the car appear to be going fast, even when standing still. It is basically a design trick, in road cars, where diffussers have little or no relevance. They are cosmetic, except for a few supercars.