DRS/ARW Speed & Chord Length

[ESPImperium]

There has been much discussion this weekend about the chord length of the Drag Reduction System/Adjustable Rear Wing/Rear Flap Adjust (what ever the teams call it) and chord length of the chord of the main flap that flips up for overtaking and top speed.

From what I've gleaned from commentary is that Mercedes have the most effective DRS with them getting as much as 20kph more from their DRS and McLaren are only getting between 8 and 12kph. This is al down to the length of chord that is in use, Mercedes using a shorter chord and McLaren using the longest available chord.

How can this be, i thought all DRS systems would provide a similar 'boost'.

[myurr]

There has been much discussion this weekend about the chord length of the Drag Reduction System/Adjustable Rear Wing/Rear Flap Adjust (what ever the teams call it) and chord length of the chord of the main flap that flips up for overtaking and top speed.

From what I've gleaned from commentary is that Mercedes have the most effective DRS with them getting as much as 20kph more from their DRS and McLaren are only getting between 8 and 12kph. This is al down to the length of chord that is in use, Mercedes using a shorter chord and McLaren using the longest available chord.

How can this be, i thought all DRS systems would provide a similar 'boost'.

Red Bull are also only getting 8 - 12 kph so it's not all about chord length.

[raymondu999]

Well if you look at the Merc system etc, they have a much shorter flap which almost goes horizontal when you activate the DRS. McLaren are still using an old style flap which has a much longer chord length. I think in terms of the flap in isolation the DRS would provide similar amounts of boost. BUT, I think that a large part of what is key is how it changes the flow about the main plane too. Which seems to be the primary differentiator for the DRS

[myurr]

In fact are you sure about that. Both Jenson and Lewis are just ahead of schumacher and similar to Rosberg in the speed trap. On the BBC coverage it was Red Bull that were rumoured to have the least effective DRS of the top teams, with 12 kmph of speed gained.

Please note that Red Bull also have the shorter flap, so it's not just about this design being superior so we can all bash McLaren for being stupid again.

[ESPImperium]

Thats something id like to be explained propperly to me, how does the flow get reattached to the DRS. I know how it worked using the F-Duct of last year, but it seems diffrent with the DRS somehow.

[nacho]

Sauber's are fastest at the speed trap:



That's a small flap and I think their actuator is very fast.


DRS or James Key making slippery cars like the FIs before?

[tc9604]

From Qualifying this morning the Mclaren flap was noticeable for the fact that it didn't seem to travel much. In contrast the Merc, as has been mentioned, appeared to move to almost horizontal.

[nacho]

From Qualifying this morning the Mclaren flap was noticeable for the fact that it didn't seem to travel much. In contrast the Merc, as has been mentioned, appeared to move to almost horizontal.

That is because the rule is about the gap between the planes not about the angle.

[myurr]

Sauber's are fastest at the speed trap:

That's a small flap and I think their actuator is very fast.


DRS or James Key making slippery cars like the FIs before?

And McLaren are only 1.4 kmph behind compared to Red Bull that are 5.9 kmph behind. So we're not talking about night and day advantage to the small flap gang, only Sauber and Rosberg are faster in a straight line and the margins are tight between all the cars.

[raymondu999]

Does anyone have speedtrap data with/without the DRS, including the differences and percentage increases?

[michl420]

In a normel race I´d expect the DRS will be used 2 to 4 times. So it will be open for maybe 20 - 40 seconds. For all other times it is closed. So it is a much bigger point how much downforce you like to lose for maybe 3 kph more high speed. I think this is the difference about the chord lenght.

[myurr]

Does anyone have speedtrap data with/without the DRS, including the differences and percentage increases?

I don't have any data but the commentators said it was worth 12kph to Red Bull, 20 kph for Mercedes and that these were the teams that gained the most and the least.

[raymondu999]

One factor i think some people have ignored is how much downforce you have without DRS. Some cars are more confident than others, and can deploy DRS earlier.

[myurr]

One factor i think some people have ignored is how much downforce you have without DRS. Some cars are more confident than others, and can deploy DRS earlier.

I presume you're referring to how early Red Bull deploy their DRS, as I haven't seen much difference in the others. Yes they have more downforce than the others so can deploy their flap earlier, but at the same time their DRS appears to be less effective at shedding that downforce which also means that they can deploy it earlier.

I think Red Bull probably gain a little on corner exit (another reason they maybe don't want to run KERS in quali but would in the race), but then they lose it down the straight.

As with everything in F1 it's another compromise.

[raymondu999]

I think Michael Schumacher was particularly afraid to let the DRS on on the exit of certain corners. Martin Brundle certainly mentioned that.