Red Bull RB8 Renault

[kilcoo316]

@kilkoo: I think theta teams were for real toying with stalling of the diffuser under tha rule set till 2008.

I'd reckon toying was as far as they would go with it. Too much risk for marginal gains. It could well have been what led them to the stalling rear wing concept.

The diffuser has some induced drag, and influences the flow around the car - stalling it ould help with top speed.

The induced drag should be very small given proximity to the ground plane and the presence of the tyre wakes.

Tricky to get the flow to reattach under braking, though, as you have to develop tricks which are not that straightforward as carving a small v at the center of your rear flap.

I'd see it as nigh on impossible to ensure it rather than just tricky!

[Rikhart]

From the look of the rear suspension arm, i think its RB8 V1.0

It´s the latest package, look at the bargeboard wing.

[Shakeman]

I'd see it as nigh on impossible to ensure it rather than just tricky!

I am convinced RB are having a go at doing that nevertheless.

The slot at the front of the car screams of F-duct and the radiator tubes that disappear into the diffuser on the V2 spec rear points to stalling the diffuser.

Any amount of fuel not carried results in reduced lap-time.

[raymondu999]

The diffuser has some induced drag, and influences the flow around the car - stalling it ould help with top speed.

The induced drag should be very small given proximity to the ground plane and the presence of the tyre wakes.

There's always this old threadif you wanna discuss that: viewtopic.php?f=6&t=8368

[Coefficient]

Stalling the diffuser hey? Sounds like it would be frought with complications that would be very difficult to overcome.

I'm just guessing here but:

You would only want to stall the diffuser when trying to achieve high top speeds so there would need to be a pressure switch in the sidepod tubes that would open at certain level of velocity induced air pressure. Would this switch not create drag inside the sidepods when the switch was closed?

Also, due to the equal pressure above and below the diffuser deck how much drag would you actually get rid of? Not much is my guess. The diffuser is the most efficient downforce inducing device on the car. Are we saying that R8 is already so refined that the game of diminishing returns is hitting Red Bull hard this year so they're looking at areas with little scope for improvement just to get a tiny bit of performance?

[OO7]

The slot at the front of the car screams of F-duct and the radiator tubes that disappear into the diffuser on the V2 spec rear points to stalling the diffuser.

That radiator tube doesn't have an exit, so the F-duct theory doesn't work.

[Shakeman]

The slot at the front of the car screams of F-duct and the radiator tubes that disappear into the diffuser on the V2 spec rear points to stalling the diffuser.

That radiator tube doesn't have an exit, so the F-duct theory doesn't work.

So it's just an ungainly bulkhead?

[OO7]

So it's just an ungainly bulkhead?

The reason for it's design has already been described so I won't delve into that. However I believe the area in which this structure meets the floor, is outside the location in which legal cut-outs or holes are allowed in the floor and having seen numerous pictures of the rear floor and diffuser from multiple angles, there are no exits which would confirm ducted airflow to the diffuser, other than the 'undercut underpass' we already know of.

[Adrian Newby]

And also, it would be tuned to dump the great majority of the downforce when going just faster than the fastest turn.

That would be a bad, bad idea.


Fancy losing much of your diffuser downforce half way through 130R when 'tuning' it?


You'll absolutely wreck the car and lose at least 1 session.

... when going faster than the fastest turn.

[Rikhart]

So it's just an ungainly bulkhead?

The reason for it's design has already been described so I won't delve into that. However I believe the area in which this structure meets the floor, is outside the location in which legal cut-outs or holes are allowed in the floor and having seen numerous pictures of the rear floor and diffuser from multiple angles, there are no exits which would confirm ducted airflow to the diffuser, other than the 'undercut underpass' we already know of.

And yet there clearly is a groove on the floor, going from where the bridge attaches, to the back. Why is that there?

[e30ernest]

... when going faster than the fastest turn.

I think that may be a handful too. A lot of factors can affect the car's airspeed. Anything from following another car ahead to changes in wind directions might cause unwanted or unexpected changes on the car's handling.

[Adrian Newby]

Instead of "stalling" the diffuser, the easiest, and most effective, bang for the buck would be to simply have the exhaust get blown more straight aft at higher straightaway speeds (which it will want to do naturally), and away from where they are attempting to seal the diffuser. No seal -> less downforce -> less drag. For basically zero penalty.

[Crucial_Xtreme]

So it's just an ungainly bulkhead?

The reason for it's design has already been described so I won't delve into that. However I believe the area in which this structure meets the floor, is outside the location in which legal cut-outs or holes are allowed in the floor and having seen numerous pictures of the rear floor and diffuser from multiple angles, there are no exits which would confirm ducted airflow to the diffuser, other than the 'undercut underpass' we already know of.

And yet there clearly is a groove on the floor, going from where the bridge attaches, to the back. Why is that there?

Of course we won't know until we get better pictures but it doesn't look like there's any kind of duct leading to the back to me. In the picture below if you look at what you're talking about, heading the the rear of the car, you can see that on the side closest to the tyre, it transitions smooth to the floor yet on the other side no such transition exists. It looks like it drops straight off.
And then there's the actual size. Very small. You're not going to get much air flowing through something so small unless it's energized, and the claim is I believe it's heat from the sidepods.
I just don't see it but of course I could be very wrong.

[Adrian Newby]

... when going faster than the fastest turn.

I think that may be a handful too. A lot of factors can affect the car's airspeed. Anything from following another car ahead to changes in wind directions might cause unwanted or unexpected changes on the car's handling.

Just about all of those things decrease the airspeed though. And a headwind would of course be calculated in to the margin. None of this is difficult.

[kilcoo316]

... when going faster than the fastest turn.

Are you suggesting tuning it using CFD/tunnel only?!? Good luck with that!