This month, Indianapolis Motor Speedway hosts the 84th Indy 500. Fans of auto racing's premier event will see changes everywhere. Engines and chassis have been redesigned to be safer and more reliable, the cars ride only on Firestone tires, and the Indy track boasts new fan amenities. Indy racing even has a new name — Indy Racing Northern Light Series.
This year's big event will also see what many hope are the seeds of reunification between two rival open-wheel-racing groups. Spectators will hear changes, too, as a new crankshaft provides a higher, more exotic pitch.
Indy's new look arose from various factors. Safety is driving many alterations. Also, the Indy Racing League is mandating changes to keep long-term team manufacturing and maintenance costs down. And IRL adds other bells and whistles this year to increase TV ratings and boost attendee excitement.
This file type includes high resolution graphics and schematics when applicable.
ENGINEERING A WINNING FORMULA
Fans in the grandstand may think IRL's biggest change for 2000 is engine sound. IRL's engine formula through 2004 calls for smaller engines cut from 4.0 to 3.5 liters. New crankshafts and the resulting change in firing order alter engine pitch and tone significantly. The IRL engine need no longer be based on a production model. That opens the door for more engine makers to produce IRL machines. Two manufacturers will provide racing engines this year — Oldsmobile and Nissan.
IRL's engine program lets teams own their engines, maintain and repair them, and rebuild the engines as needed. The engines must meet minimum weight and size requirements and fit all Indy racing chassis. The league, through a mandatory rev limiter, will again control engine speed. If engine rpm rises above the rev limit, electronic controls will make the engine misfire briefly. Momentary misfiring is a safe way to slow down without compromising car handling, say IRL officials. Rev limiting is a 5-min programming job for an IRL technician. Once set in an engine's electronic control unit, the limits can't be tweaked by pit crews.
Nissan and Oldsmobile worked overtime during the off-season to produce race-worthy engines that meet the specs.
For this season, Oldsmobile has had to tinker with success. The IRL Aurora V8 powerplant, built by GM Racing, stood undefeated as of March, winning 31 consecutive IRL races. A quick glance at the new 3.5-liter IRL Aurora V8 gives nothing away. Externally it's identical to the old design. But inside it carries a new short-stroke 180° crankshaft design, new camshafts, and new tapered-beam connecting rods that are 0.180-in. longer than those used in the 4.0-liter version.
"We maintained the IRL Aurora V8's 93-mm cylinder bore diameter and 8.1-in. deck height, allowing builders to use the same block, cylinder heads, and many other components in our previous 4.0-liter engine package," explains Joe Negri, GM Racing IRL/Road Racing Group manager. "The IRL Aurora V8 already met the IRL's maximum bore size, minimum block height dimension, and 340-lb minimum weight, so there was no need to produce an entirely new engine package for the new formula."
IRL's main objective in instituting smaller engines was to cut speeds and increase safety.
"I think the 3.5-liter package will meet the league's objective which was to cut horsepower about 50, 60, or 70, to slow down the cars," Negri says. "Based on the results of the Delphi Indy 200 in January, it's a good thing we went down in displacement because the cars are brand new and better, and the speeds aren't down as much as I think the IRL may have wanted them."
Negri says an IRL Aurora V8 produces approximately 3 hp/in. 3 So reducing displacement by 0.5 liter, or about 30 in. 3 , is expected to cut output by 90 hp. But faster engine speeds — 10,700 rpm maximum, up from 10,000 rpm in 1999 — and higher efficiency offset reduced piston displacement somewhat. Piston speed is a major factor in engine reliability. Because the 3.5-liter engines have a shorter crankshaft stroke, piston speed drops by more than 150 ft/min, improving overall durability.
And what about that new Indy-car sound? Thanks to the 180° crankshafts, race engines no longer have that big American throaty V8 sound, but instead have a high-pitched Indy car shriek. Here's why. The older 90° crankshaft configuration had two cylinders on each bank firing in succession, and two cylinders had longer intervals between firings. These irregular intervals between exhaust pulses produced a low rumbling sound. With the 180° crank, cylinders fire alternately from bank to bank in even intervals. Evenly spaced exhaust pulses, in conjunction with higher rpms, come out at a higher pitch and tone.
The new crank is called flat because its necting rod pins are at 180° intervals that are in a single plane and produce a flat "two dimensional" configuration. Both the 4.0 and 3.5-liter versions of the IRL Aurora V8 are "90° V8 engines" in that the included angle between the cylinder banks is 90°. Also, the interval in degrees of crankshaft rotation between cylinder firings is 90° with a conventional 90° crankshaft or a 180° flat crankshaft.
The 180° cranks are optional so racing teams can consider advantages and disadvantages of using the new design. Oldsmobile's lead design engineer for the IRL Aurora V8 program, Roger Allen, says the 180° crankshaft can be lighter and stiffer than a 90° version. This helps cut crankshaft inertia which boosts acceleration on a short track. Allen says the 180° design can also improve engine output by optimizing exhaust tuning. In other words, by adjusting the diameter and length of the header pipes, scavenging is improved. This can be done by tuning the acoustical waves in the exhaust pipe so that pressure pulses help remove the exhaust gases.
Several different firing orders are possible with a 180° crankshaft. GM Racing engineers initially selected the 1-8-5-4-7-2-3-6 sequence because it works with the same camshafts for the right and left cylinder heads while still producing as much power as other firing orders.
As is the case with most new designs, there are some hurdles to overcome. For example, the 180° crankshaft is inherently unbalanced, say Oldsmobile officials. A V8 with a 180° crank is essentially two four-cylinder motors conjoined by a common crankcase and has a reputation for vibrating.
Negri says Oldsmobile's been designing compensating measures such as timing chains to handle increased vibration and higher rpms. Indeed, the undefeated Oldsmobile team seems to cope with such occasional problems quite well. Negri credits the engine's success to an extensive support system and talented builders.
"It is important to develop a support system for our engine builders so we can get them the parts and technology they need," Negri points out. "We've aligned ourselves with excellent OEM engine builders. When we run into problems, we have seven or eight of them looking at the problems and solutions."
Challenging Oldsmobile's success is the Nissan Infiniti Indy team, whose motto is "head down, work hard." Its plan of attack this year is simple — win races. Infiniti began supplying a racing version of its Q45 performance luxury sedan V8 engine to Indy racing teams in 1997, but has yet to win an IRL race. The goose egg is not for lack of trying, but most likely from being far outnumbered: Infiniti powers just one car that belongs to veteran race-car driver and 1998 Indy 500 champion, Eddie Cheever Jr.
The new season and new regulations have renewed Nissan's hopes for getting to the finish line first. In fact, it looked as if Infiniti would claim its first victory in the Delphi Indy 200 at the Walt Disney World Speedway last January. With nine laps to go, Eddie Cheever Jr. overtook Buddy Lazier for the lead in the 200-mile race. But two laps from the finish, Cheever tried to put a car between them but got caught up in slower traffic. Close followers Robbie Buhl and Lazier got a chance to sneak by and dropped Cheever to a third-place finish.
"The engine was very strong that day," Cheever says, "and it kept getting stronger and stronger. Believe me, I did everything I could to break it. I pushed it to its limit and it just kept giving.
"That race was a great example of the competition in this league. There is a lot of blocking going on now. You need to get a lot of momentum to pass people. The 3.5-liter engine is going to make it a game of momentum. It's going to get even more exciting."
Cheever ran the Delphi Indy 200 on last year's 4.0-liter Infiniti Indy engine converted to a smaller capacity by changing the stroke, pistons, and connecting rods. However, an all new Infiniti Indy engine, the 35A, has been under development since 1998 and is expected to compete in the 500. The lighter, more compact package will have a lower center of gravity than the earlier version. Interest-ingly enough, the 35A comes from the 5.0-liter engine Nissan entered in last year's Le Mans. The new 35A design comes courtesy of the U.S. design team and Nissan's Motor-sports group in Japan.
Frank Honosowetz, Infiniti Motorsports manager, says switching to the smaller, faster-revving 3.5-liter engine brought several advantages.
"Theoretically, the 3.5-liter engine should be more reliable," he explains. "One of the issues with the 4.0-liter engine formula was piston speed — in particular, the jerk, or the rate at which the piston decelerates, stops, and accelerates from top and bottom dead center in the cylinder bar.
The reduced stroke slows the mean piston speed and the rate of deceleration and reacceleration, so parts have it easier. And engine speed is only modestly higher — we went from 10,000 to 10,700 rpm maximum."
The 35A incorporates the new 180° crankshaft and a piston firing order of 1, 4, 5, 2, 7, 6, 3, 8.
"It will be interesting to see what happens at Indy because there will probably be about a 50/50 mix between the 90 and 180° cranks," says Honosowetz.
Of course, in the end all that really matters is going fast and going long. As Cheever points out, "The worst sounding engine that wins a race is all of a sudden the best sounding engine."
A SAFER RIDE
The souped-up powerplants will rest in redesigned chassis produced by Dallara Automobili Sal (Italy), G-Force Precision Engineering Ltd. (Great Britain), and Riley & Scott Inc. (Indianapolis). Safety is the driving factor in chassis changes for 2000.
Last May, three spectators were killed during an IRL race in Concord, N.C., when a wheel was deflected into the stands. Working together, all three chassis makers helped speed development of restraint devices known as suspension wheel energy management systems (SWEMS). The system consists basically of small cables that keep parts from flying off in a crash. The cables are wound from high-performance fiber Zylon and have a breaking strength of 5 tons. The system was in place and mandatory in the 1999 Indy 500.
"Our race cars spend more time above 200 mph than any other type of race car in any other series," says retired IRL Executive Director and Indianapolis Motor Speedway Vice President, Leo Mehl. "The energy created in crashes at these speeds is hard to comprehend. Data has shown these impacts can generate up to 60 to 80 gs. Knowing this, it was important for us to develop a system that would provide the most opportunities to retain wheel assemblies in crashes."
This year, a stronger SWEMS with better cable attachment points is in place on the all new chassis. Sam Garrett, U.S. technical representative for Dallara, explains.
"For 2000, we changed the way that some of the cables mount to the main part of the chassis and to the hub upright assembly," he says. "There are two cables for each wheel, one at the top and one at the bottom, and we made the lower cable stronger than it was last year."
This, however, is just one of many enhancements boosting safety for drivers and fans alike. For example, the cockpit opening is wider at 19 in.
"The wider cockpit opening was done for two reasons," explains Riley & Scott's chief designer, Carl Seaburg. "There's a deformable structure that forms a collar around the driver's helmet and bridges the space between his helmet and the new wider cockpit side, providing more crush area. That makes it easier to remove a driver who might possibly have a neck or a back injury. The IRL has done a very good job from the start specifying some of the considerations that are important, such as the crush structures on the side of the car and mandatory crash testing and roll hoop testing. None of that is new but is a very big part of the safety package."
Garrett agrees. "When it comes to safety we all want to do what we can," he says. "Racing is not necessarily a safe sport. There are inherent dangers in going that fast. But when there is a problem of the magnitude that we had last year after the fatal accident, we need to do something. It's impossible to make a system that guarantees absolute safety in every possible racing accident, but we will keep evolving as we learn more about what works and what doesn't."
One chassis component that will not return, according to IRL officials, is a vertical appendage known as the "fan fin" mounted on the engine cover.
"We're confident that the changes made for the new Indy Racing chassis will not only make the car safer for the drivers, but will thrill the race fans," says IRL's Director of Racing Operations, Brian Barnhart. "These new designs, combined with the sound produced by the 3.5-liter engines, have resulted in an exciting package."
Seaburg is certainly excited about the new Riley & Scott Mark VII. When compared to the old Mark V that ran between 1997 and 1999, the biggest change is in aerodynamics.
The new aerodynamics are based on more than 40 days of wind-tunnel testing at Renard's Automotive Research Center (ARC) in Indianapolis, run by Riley & Scott's project engineer, Chris Finch. The Mark VII chassis was designed and produced in collaboration with Reynard Motorsport, which owns Riley & Scott. Computational fluid dynamics and FEA were also used in the design.
Wind-tunnel tests took place on a scaled-down version of the car — a 40%-sized model, in fact, accurate down to the suspension, wheels, tires, and structure. The model even has removable body parts and wings to more accurately represent the actual car.
"The data reduction system at ARC is really quite sophisticated," says Seaburg, "and our aerodynamicists can select any number of ways to look at the data."
Dallara engineers also spent a lot of time in the wind tunnels trying to make a car that had the same amount of downforce — which translates into grip — but less drag. "The last three years we've basically run the same car," says Garrett. "We were able to make small changes to the bolt-on body work, which for an Indy car consists of undertray, side pods, and engine cover. For 2000 we built a completely new car from scratch, still following many of the same rules but with significant changes geared toward safety."
So, how do IRL chassis manufacturers gain a competitive advantage in the face of strict mandated design specifications?
"There are still opportunities to gain an advantage even though the cars are dimensionally similar," says Seaburg. "If you expend your wind-tunnel resources carefully, and have a good program, you'll find your advantages."
FIRESTONE IN AT INDY
The exciting and hard-fought battle between Goodyear and Firestone for top race tire at Indy is on hold. The big news this year is the switch to a sole tire supplier.
Last October, Goodyear announced it will not supply race tires to CART or the IRL series citing difficulty justifying the significant cost and resources such a commitment entails.
The decision left IRL's Mehl, who spent more than 30 years in Goodyear's racing division, both surprised and disappointed. "After being a Goodyear employee for so long, the first thing I think about is the thousands of dedicated employees who worked so hard to design, build, and service race tires for the Indianapolis 500 since 1964."
Mehl characterizes the competition between Goodyear and Firestone in the IRL as healthy and exciting. Both have won 17 races and two Indianapolis 500s since the league began in 1996.
But, says Mehl, "Since Firestone returned to Indy Racing, it has provided excellent tires, support, and enthusiasm to the teams and drivers."
That sentiment is echoed throughout IRL. "Being with Firestone will equalize things," says team owner Dick Simon, Dick Simon Racing. "I've worked with both Goodyear and Firestone and felt that the Goodyears were better for qualifying but Firestones are better for the whole race. We haven't had any problems with the Firestone tires."
Simon used Firestones last year for two sessions because tire wear and adherence didn't change.
"We started a race and within just a few laps, when the tires were hot, they would stay almost the same for two sessions before we actually started to loose the grip," Simon explains. "When you take the tire off its still got rubber on it and good adhesion. I think this will level the playing field."
Two-time Indy 500 champion Al Unser Jr. agrees. "The Firestones are lasting longer than the Goodyears did. The initial tire grip is very close between the two, but Firestone definitely has consistency over Goodyear."
Despite compliments like these, don't think Firestone is resting on its laurels. Its engineers are challenged by other factors such as different road surfaces, changes in weather, and the race itself.
Says Al Speyer, motorsports director for Bridgestone/ Firestone, "It's a significant challenge preparing for the different road surfaces and the constant changes to the car, engines, wing, and aerodynamics. It boils down to a large ingredient of experience, having been there and having done it."
And experience is one thing Firestone has with 50 Indy 500 victories under its belt. The 2000 IRL race tire is Fire-stone's Firehawk.
Designing a winning race tire is quite different than designing other components, according to Speyer.
"It's an evolutionary process of going out and trying changes to current designs," he says. "Unlike some other industries that are fairly well advanced in computer modeling, we use actual on-track, ambient conditions that are crucial to tire performance. We actually put a set of tires on a car and run it around the track. Sensors on the car measure air pressures, temperature, and performance qualities."
In planning for different tracks, engineers pay particular attention to the surface, degree of banking, corner angles, straightaway lengths, elevation changes, and bumps or irregularities in the pavement. They also must consider the race itself — length, speed, and g-forces that can affect lateral traction, braking, and steering. And of course the weather. Fluctuating temperatures can change ability to grip, as well as inflation pressure. Because the IRL uses only slick, nontreaded tires for its oval track races, teams can't switch to different tires for wet or dry conditions as they do in CART competition. Another element to consider is driving style.
"There's a significant art in race-tire engineering," Speyer explains. "Not every driver drives the same way. Some like a car that understeers a little bit, and some might like a little bit more oversteer. It's a challenge for us to make tires that will perform under such a wide variety of conditions, even at one racetrack."
Firestone race tires for IRL fall into three basic categories: those for one-mile ovals, for 1.5-mile ovals, and for Indy-caliber superspeedways. Each race tire is bar coded for tracking everything from the car on which it ran to ambient and track temperatures and operating speeds. After a race, tires get dissected and studied, then destroyed and used as fuel in cement kilns.
According to Speyer, Firestone's design philosophy hasn't changed much as the sole tire supplier.
"We always shoot for carcass durability and structural integrity; safety-wise, it's our top priority," he says. "The tread compound and how the tire holds up is a secondary priority but is still very important to us. We're not as focused on ultimate grip level since we aren't racing for ultimate lap speed. That's one thing we are willing to give up a little. Hopefully that provides a longerwearing tire. Because everybody runs the same tires, its not a competitive advantage or disadvantage."
QUEST FOR THE CHECKERED FLAG
Once the green flag waves, this year's race will offer something not seen recently: CART teams in an IRL race.
CART left a large gap in its racing schedule to accommodate teams hoping to race at Indy, and a couple will do just that.
Widely considered to have open-wheel racing's most well-known drivers, CART has seen one of its stars defect to IRL for the 2000 season. Al Unser Jr. has had success in CART and at Indy, winning the 500 twice before CART quit racing at the brick-yard. "Little Al," as fans call him, is more than a little happy to be back.
"Well, heck yeah I'm excited. I'm gonna be 38 and I'm a rookie," he says. "The only thing on my mind about the Indy 500 is making the show. If we qualify, then we'll talk about the race."
Finally, this year's big race will also feature something else not seen in quite awhile: a female driver, 19-year-old Sarah Fisher driving for Walker Racing.
Engines and chassis aren't the only things sporting a new look in 2000. The Indianapolis Motor Speedway (IMS) has undergone a multimillion dollar reconstruction to not only gear up for the 84th Indy 500 but also to make room for Formula One's return to the U.S.
Debuting this fall at IMS, the Formula One U.S. Grand Prix returns in what will be its first appearance here since 1991. Revving up for the event has IMS constructing a 2.6-mile road course incorporating the front straightaway, part of Turn 2, and Turn 1 of the 2.5-mile oval.
But the improvements don't stop there. As many as 36 new Formula One garages and 12 suites were added along with a new Pagoda control tower, a state-of-the-art media center, and a widened tunnel running under the track that serves as a passageway for fans.
A new timing and scoring system called a "multiloop system," comes from the Netherlands-based developer AMB i.t. It is fully digital and uses multiple detection points around the oval to track time, speed, and scoring data of many cars.
The system enables turn speed, straightaway speed, and pit-road speed all to be tracked at timed intervals. This data is then processed and displayed through scoring monitors, track scoreboards, video monitors, and television feeds. Timing is claimed to be accurate to 0.0003 sec.
Perhaps the most important feature at the speedway — the Polyethylene Energy Dissipating System barrier (PEDS) — was new last May, but has been improved for 2000. The new PEDS-2 system runs along the inside wall of Turn 4 and consists of overlap-ping polyethylene impact plates fastened to 16-in. cylinders. However, a new 12-in. secondary polyethylene cylinder now sits inside each existing 16-in. cylinder in each barrier module. The impact plate upper portion is folded over the top of the cylinders, and every module anchors to the concrete wall via steel cables and new horizontal cables.
"The new cylinders will provide more progressive energy dissipation during impact," explains designer John Pierce, retired GM Motorsports engineer who serves as a safety consultant to the IRL. " The wall now better accommodates the safety needs of all the vehicles competing at the Indianapolis Motor Speedway, from light IRL cars to heavier NASCAR Winston Cup and IROC stock cars."
Engineers at the Midwest Roadside Safety Facility at the University of Nebraska-Lincoln helped the IRL safety committee redesign the system.
GEARING UP FOR RACE DAY
Adding to the list of chassis improvements is a new gear-box with a sequential shift pattern from Xtrac Ltd., Berkshire, England. It has a layout similar to last year's H-pattern design in that it is a conventional single-seater with a cluster of gears mounted longitudinally behind the axle line, but the Xtrac gearbox requires that drivers change gears in order. Rather than using an H-Gate system to select a gear, the Xtrac shifter only moves backwards and forwards to change up and down respectively. The gear lever returns to its central position after each shift and there are two neutral positions at each end of the sequential sequence.
According to Jon Marsh, Xtrac's senior design engineer, last year's transmission could be awkward when changing gears for several reasons.
"Because the cars only race on oval tracks there are minimal gear changes. In qualifying trim, drivers can run flat out without needing to change gear, however, in a race situation, the driver needs a close spread of ratios available to allow for traffic or a change in track conditions. Shifting is now easier and quicker and allows the drivers to gain peak performance from their race cars."
Xtrac used Unigraphics 3D CAD software in designing the new gearbox.
Explains Marsh, "It's great to be able to work in 3D. It not only improves the design, but can also simplify manufacture. When we made the casting patterns, we simply downloaded the 3D models straight to the milling machine, negating the need for handmade wooden fabrications. We get a much more accurate product at the end of the day."
Servicing the gearbox is said to be much easier with the new design. A cassette-style ratio change allows rapid gear removal and there is separate drop gear access to adjust the terminal speed of the race car — all without disturbing the gearchange or rear suspension. It also features a dry sump lubrication system with an external plug-in oil cooler, with no external oil lines.
"We've radically improved servicing the gearbox compared to last year," Marsh says. "Even though the teams aren't changing gears much while they're driving, in testing they're coming into the pits a lot and fine-tuning the ratio for the track and differing conditions. We've cut the labor dramatically."
Each gearbox leaves the factory ready to install, having been tested using a spin rig/dyno to check gearchange quality and lubrication flow and pressures. The rig can be articulated to replicate acceleration and cornering G-forces.
Out with the old, in with the new
3.5-liter V8 engines
4.0-liter V8 engines
10,700-rpm rev limit
10,000-rpm rev limit
Gearbox with sequential shifter