FEBRUARY 2, 2011
Interview: Williams technical director Sam Michael
Q: Rubens says there are concerns about so many cockpit buttons?
It's quite busy in the cockpit, that's for sure. We saw that over the winter in the simulator. It's pretty hard work but they'll get used to it!
Q: Have you changed the design of the steering wheel much?
The wheel is the same all we have is a button there for the moveable wing. This one you are using every lap so you need to have a button you don't have to look for, like the radio button. In a qualifying situation as soon as the driver comes out of a corner he's going to be full throttle and on that button to reduce the drag.
Q: How quickly does the wing all get back to full downforce?
We're down to a few milliseconds. Ours system is hydraulic, I don't know if everyone is using hydraulic. We couldn't see how you could do it electrically. Well, you can do it but it's going to take a hundred milliseconds to move whereas if you are doing it hydraulically it's 10 to 20 milliseconds. So when a driver comes off the button it's back in 20 milliseconds or it comes off as soon as he applies brake pressure. We did some work in the simulator and said, right, keep your finger on the button and when you press the brakes allow the system to automatically bring it back. You lost out in that first few metres of braking so it became pretty clear that you always want a driver to lift off the button just as he touches the brakes. It's working okay aerodynamically, which is good, and it's very quick -- moving 50mm in 20 milliseconds is very fast. The mechanics want to put a tennis ball in there to see how far it would go!
Q: How was it in terms of a first day?
Pretty good actually. We had a problem with KERS in the morning, with what we call the MGU (Motor Generator Unit) that cost us two and a half hours mid morning. We just disconnected it because we didn't want to cost any more time. We didn't run KERS in the afternoon. That's the only problem we really had. There were no problems with temperature or with parts rubbing or breaking or anything like that. We still got 77 laps in which, considering we lost that time, is not bad. The car seems to be working like it should and all the loads measured like we predicted they should. We can now start working on set-up. Today we just did some very basic mechanical tests and some aero mapping in the pit lane to scan the front and rear wings just to make sure the car does what it's meant to aerodynamically. We wanted to do a full size wind tunnel test before we came here but ran out of time and we'll probably do that before the Jerez test.
Q: How much of the Williams KERS unit is proprietory?
There's three main parts to it - the battery pack, which is completely designed and assembled at Williams. The little cells that go into that pack we don't make, we buy those. Anyone can buy them , we don't own the intellectual property to them.
Q: So where would you buy them?
Can't say! They come from a faraway land. Very far east. We buy the cells in and assemble them in-house. It's an amazing difference in cost, I'd say a cost factor of designing and building your own battery pack is probably 30-fold versus going to a company and asking, can you make us this? We went through that experiment and thought there was no way we could afford to do KERS on that basis, so we employed a couple of technicians and did it in-house.
The second part is the MGU, which is completely a Williams part developed within the F1 group, with the help of the university. The electronic control unit, most of it comes from a standard ECU anyway but any control electronics are ours as well. The inverters are all made inside Williams and the last bit is the mechanical drive on the engine, to feed the power into the crankshaft, which is Cosworths.
Q: By University do you mean Qatar?
Q: So which one?
Q: How did you find the Pirellis?
It's early days. They don't look too bad, they're not falling apart, there's no graining or anything but our set-up is not there in terms of using them. You can see that from the way the drivers are talking and are not happy with the balance. We haven't done much yet so we need to get into sorting our aero map, weight distribution and the general mechanical set-up, not that you can do much on weight distribution these days.
Q: Rubens said he thought that the medium compound tyre was a bit stiff?
Yeah. To be honest they do look like that because you're not seeing massive temperature but you probably wouldn't in these conditions anyway.
Q: Can you speak about the gearbox casing and differential?
The main target was to clear all the area to the rear lower wing because it's a performance differentiator now. You've got to have the underside of the rear lower wing completely free, so we took the decision to lift the top wishbone and the track rod and went to a Z-bone layout which was commonly used in the early nineties to get that all above the underside so that all the weight is all inline with the trailing edge of the legality box, so you are nowhere near the underside of the rear lower wing and it's completely free airflow.
The pull rod was a no-brainer because it doesn't matter what you do with a pushrod, even if it's swept forwards or backwards you've got a load going into the rear lower wing, whereas a pull rod is completely out of the rear lower wing. That was an easy decision. Then the other thing was to clear the centre of it by lowering the gearbox. We dropped the top section as much as we could and so it's the smallest box we've ever made. We took that decision in March last year and we've done quite a few thousand kilometres on the dyno with that rear end. That was quite a big step on driveshaft angle, definitely the most extreme I've seen. The people we did the driveshaft design with had never done anything that extreme before. It was quite a big programme.
Q: Is there no performance loss with that degree of angularity in the joint?
It's pretty small with the tricks they've got nowadays, pretty impressive stuff.
Q: Have you had a peek at anything else in the pitlane and seen anything trick?
Everyone has really pushed little bits and pieces, whether it's lowering the final drive more like Red Bull or Renault have done or getting tighter coke bottle rear ends or more elements on front wings, all the normal things you're trying to do. The only different thing is this Renault blown exhaust out of the front and the Toro Rosso double floor thing. We tested that a couple of times in the past and it didn't do anything for us, but Renault blowing out the front is interesting.
Q: What's that about?
I don't know yet. We'll let you know when we do! I'll have a look in CFD. We didn't think of it.
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