Indianapolis - the engineers view 23 Sep 2003
Willy Rampf, Technical Director, Sauber:
"Indianapolis Motor Speedway has two main characteristics that make it a medium to low downforce circuit: the banked final corner that combines with the main straight to make the longest high-speed run in Formula One, and the tight infield section. Ideally you need low downforce for the former, but plenty of grip in the latter, and these are mutually exclusive. The compromise on downforce you choose thus has a critical effect on the car's performance over the course of the lap, and this year that will be even more important because of the rule that you have to race in the same trim that you qualify. I think most teams will opt for low downforce, because it is always very difficult to make up any places that you lose on top speed down the straight once you get to the twisting part of the circuit. In qualifying I think everyone is going to be right on the edge. The tight right, left, right first corner also demands very good stability under braking if the drivers are to have a chance of overtaking there. There are plenty of different lines that you can take there, so it's a prime passing opportunity.
"Like Monza, the track places a high premium on engine performance and reliability, but the C-spec Petronas V10 went well in Italy and we are also optimistic that our latest aerodynamic configuration will prove competitive in
Geoffrey Willis, Technical Director, BAR:
"The Indianapolis F1 circuit is a circuit of two halves. Part of the circuit consists of the famous Indy 500 oval speedway incorporating Turn one and the pit straight, but run in the reverse direction, the other part of the circuit is a series of tight infield loops with similar characteristics to Hungary, in that it is slow and difficult to overtake, but with even less grip. The last turn is flat-out, so exiting the previous corner well is important to avoid being caught on the long oval section, which allows a good opportunity for slipstreaming and the possibility for passing under braking at Turn one. The set-up of the cars has to be a compromise between the requirements of the two sections with a level of downforce on the low end of intermediate. This and the low-grip infield mean that the teams will have to find the right compound between high-grip soft compounds and tyre wear and blistering. The Indy track is reasonably easy on the chassis, suspension and brakes, with its smooth surface and shallow kerbs. However, the long straight at this track can cause particular problems for the engine, which stays on full power for a longer single period than any other track in the calendar. This, followed by the sudden heavy braking to an extended period of slow-speed running, can lead to reliability problems."
Sam Michael, Chief Operations Engineer, Williams:
"Indianapolis is a unique circuit with a slow speed infield section followed by a long straight that goes through the oval - something that takes 22 seconds of full throttle. It is interesting for the driver and the engineers as most of the lap requires maximum downforce, while for the straight you want to run as little wing as possible.
"As the championship battle is so tight, any small error by the team will really hurt the title hopes. Points scored at the first Grand Prix are worth as much as the ones scored at the final races, however, at this time of the season there is not enough time for recovery.
"Strategy should be interesting at Indy as it has turned into a game of how little fuel you dare run. This is amplified when the cars and drivers are so close in terms of performance. We will be taking some new mechanical and aero components to help squeeze the last bit of performance out of the FW25 for these two vital final races."
Norbert Haug, Vice President, Mercedes-Benz Motorsport:
"The US Grand Prix will be a crucial race for the outcome of the World Championship with the top three drivers covered by just seven points and a maximum of 20 points still at stake for each of them. The combination of the 1.7 kilometres long oval section with the slow and tricky infield makes the Indianapolis Grand Prix circuit a real challenge for the chassis, the engine and the tyres. One unique feature of the circuit layout is its long high speed part of 23 seconds of uninterrupted full throttle. In total 55 percent of the lap are run on full throttle. To race at Indianapolis is something very special for Formula One. Indy is the 'Capital of Motor Racing' as it calls itself, and we are looking forward to an exciting race in front of a huge crowd and hundreds of millions of television viewers worldwide who keep their fingers crossed for at least one of the three championship contenders, Michael, Juan Pablo and Kimi."
Denis Chevrier, Engine Operations Manager, Renault:
"The principal feature of the circuit is of course the main straight, which, at 22 seconds, provides us with the longest continuous full throttle period of the year: in spite of the severity of Monza, for example, the longest uninterrupted acceleration at the Italian circuit is only fifteen seconds long.
"The main straight itself poses the additional problem of slipstreaming, and this can potentially cause over-revving unless the final drive ratios are adapted to take account of it. Furthermore, the widely varying characteristics of the circuit, with speeds from over 330 kph to under 80, place demands on the engine throughout its operating range. While providing a progressive, driveable engine is always an objective for the engineers, it is of particular importance at this circuit.
"The baseline specification of the race engines is the same as that which was raced in Monza. They will feature the cylinder head which made its race debut in Italy. Some small developments have also been undertaken which should allow us to increase engine revs."
Mike Gascoyne, Technical Director, Renault:
(Q: After a slightly downbeat weekend in Monza, do you expect things to pick up again in Indy?) "Monza was disappointing because Jarno (Trulli) especially looked set to have a very good run. However, I think Indy will suit our car better, and that we will be very strong there. The engine upgrades we introduced in Italy will be run at Indy, which will help us down the straight, and I think we need to be looking to finish on the podium."
(Q: What are the key factors for having a quick car at Indianapolis?) "Although the downforce levels used at Indy are not as low as those we saw in Monza, there is still one very long straight for which we need to tune the top speed. The length of the straight makes aerodynamic efficiency into one of the key factors, and that is a strong point of the R23B. In terms of our aerodynamic performance, we are still at the very top level relative to our competitors, and that gives me confidence for the race."
(Q: And once more, Friday testing should prove an asset...) "The facts are simple: we tested as much as the other teams last week at Barcelona, and had a very productive session. On top of that, we will have the benefit of added running on a circuit where nobody is able to test. Even on the dirtiest circuits this season, we have obtained extremely useful data, and I believe that will be the case once again this weekend."
Pat Symonds, Director of Engineering, Renault:
"Recent weeks have seen a number of debates over tyres and they will undoubtedly be key: we fully expect to see a more aggressive tyre choice than was the case (here) last year. It might be thought that the banking alone makes Indianapolis a hard place for tyres, but this is not the case: while the loads are of course high on the banking, owing to the high speeds in this part of the circuit, the forces are no higher than those we encounter at other venues. Indeed, the load on the tyres is reasonably well balanced between the front and rear of the car at Indianapolis, so much so that a particular set-up will determine whether the front or rear tyres require the more careful management.
"Wear rates, blistering and indeed any graining, will largely be a function of how aggressive the teams are in their tyre choice but generally speaking, for the Michelin runners, we expect quite low wear and little or no graining. Equally, we are not concerned by the prospect of blistering at this circuit. Degradation (the rate at which the tyre loses performance) was quite low here last year, and although we expect it to increase slightly this weekend owing to different compound choices, it is not expected to cause any concern.
"In 2002, tyres dictated that half the field made two pit-stops, while the other half did a one stop race; for 2003, I expect strategies to be slightly more interesting than usual. Under the new rules, we have generally seen all the races have one more stop than last year, but the length of the pit-lane in Indianapolis, coupled with the high-speed nature of the circuit alongside, perhaps make it unlikely that anyone will go for three stops. The effect of the fuel load on lap-times is slightly lower at Indy than at the average of circuits, and while fuel consumption is average, this may lead to slightly longer first stints than usual; overall, though, I think we can expect most teams to be on what we might now term a conventional two-stop strategy."
Hisao Suganuma, Technical Manager, Bridgestone Motorsport:
"Indianapolis is quite a challenge for a tyre manufacturer. It is a conflicting combination of long, fast straights where cars reach speeds in the region of 320-330 kph and a much slower infield section. These two characteristics mean we need to provide our teams with tyres from the softer end of our compound range in order to provide competitive high grip levels in the infield section but we also need those compounds to have good heat durability on the high speed sections. This is no easy task to achieve but we will have several new specifications in the US all of which we expect to be competitive on this circuit."
Gary Anderson, Director of Race and Test Engineering, Jordan:
"Indianapolis is a very different type of track and it's really enjoyable to race at a circuit with so much history. In F1 we usually do things a bit differently, here it's the same and we go the opposite way round the track to everyone else that uses it. The track has a very slow, smooth infield, with a high-speed straight down the brickyard section. It makes grip level at the infield very low because we run low downforce levels, meaning there have to be fairly big compromises in terms of set-up. With qualifying and the race now, where you can't adjust the car in between, it makes it double-difficult. Normally you could get a better lap time by running slightly higher downforce, but in the race that would mean being overtaken down the straight - so we could see some excitement in qualifying with a few mistakes down to the cars running with such low downforce.
"We're going into the last two races fighting, intending to drag more points from a taxing season. It's a shame to be at this point in the season with lack of development hurting our chances, but we won't give up! You never know what is going to happen and hopefully we'll be able to take advantage of whatever drops in front of us and reap the benefits of other people's mistakes."
Pascal Vasselon, F1 Programme Manager, Michelin:
"Indianapolis is pretty much two tracks in one. The banked section accounts for about one third of the circuit's length and features the season's longest stretch of flat-out driving. The infield section, meanwhile, is very slow and incorporates sequences of tight corners that wouldn't look out of place in Monaco.
"These two distinct facets compel us and our partners to focus as much on aerodynamics as we do on tyre compounds. The fastest part of the circuit generates a great deal of heat, particularly where the left-hand tyres are concerned. The banking offsets some of the centrifugal force by increasing the vertical load and this places a massive strain on tyres. It tests our rubber to the limit and our tyre compounds are principally designed to cope with this, the circuit's most challenging element.
"We will be bringing just two different types of dry-weather tyre to Indianapolis. They are based on new constructions that were developed prior to Monza.
"The nature of this track obliges us to compromise and opt for tyres from the medium sector of our range. If we brought tyres that were too soft, they would be ill suited to the banking. Hard tyres would struggle to generate adequate grip through the tighter sections of the track and would slide around too much. The surface on the banked area of the circuit is very abrasive. The infield, on the other hand, is fairly smooth; and this is the most significant contrast between the two different parts of the track.
"A two-stop strategy will probably be the favoured tactic here, given that the fuel weight penalty is relatively slight; less than 0.3s seconds per lap for every extra 10kg; and pit stops are relatively swift, at about 28 seconds per visit."