The 89th installment of the Pikes Peak International Hill Climb opens this weekend, which means that now seems like an appropriate time to provide a preview of what is arguably the world's most famous hill climbing competition.

Represented by drivers and racers from ten different countries - France, Italy, Japan, Spain, New Zealand, Sweden, Mexico, Australia, Great Britain and the USA - the 2011 Pikes Peak International Hill Climb will feature 194 different racers, all of which are looking to win their respective classes and break some records in the process.

The festivities start on June 24th in downtown Colorado with the Fan Fest, a free event that is expected to gather about 35,000 fans from 5:00-10:00 pm. As part of the festivities, fans will get the chance to see all the participants with their racers, as well as enjoy live music, motorcycle jumps, the Denver Broncos cheerleaders, and, of course, a chili cook-off.

Even Hollywood star and car aficionado, Paul Walker, will be on-hand for the event as he was tapped to be the driver of the Porsche 911 Pace Car. Riding shotgun beside Walker for the ceremonial lap will be Colorado Springs, Mayor Steve Bach.

Check out our preview of the 2011 Pikes Peak International Hill Climb after the jump.

Mayhem in the Unlimited Class

The unquestioned crown jewel event of the annual Pikes Peak International Hill Climb has always been the Unlimited Class where some of the fastest machines on the planet are put to the test to see which one can go up the mountain faster, with the unwritten goal being who could crack the 10-minute barrier first.

The Contenders

Nobuhiro "Monster" Tajima/Suzuki SX4 Climb Special

The closest racer to achieve that mark was five-time champion and record-holder Nobuhiro "Monster" Tajima who set the current record back in 2007 at just a shave over ten minutes - 10:01.408, to be exact. This year, Monster Tajima and his 910-horsepower Suzuki SX4 Climb Special will once again lead a group of hopefuls, all of which have the same goal mind: posting the very first sub 10-minute mark in Pikes Peak history.

Rhys Millen/RMR Hyundai PM580

For this year, Rhys Millen will be bringing back his RMR Hyundai PM580 for another go-around at Pikes Peak. Last year, Millen wanted to bring the overall record back to the family - his dad, Rod Millen, held the record for 13 years before it was broken by Monster Tajima in 2007 - and while he didn't exactly accomplish his goal, he returns for 2011 more determined than ever to break Tajima's four-year stranglehold on the record books. Expect some fireworks when Rhys brings out the PM580 and its heavily modified 4.1-liter Hyundai Lambda V6 engine with 775 horsepower and 750 lb/ft of torque.

Paul Dallenbach/Banks Power 1,307-horsepower race car

Another individual determined to etch his name in Pikes Peak lore is Paul Dallenbach, the head of Dallenbach Racing. Together with its partner, turbocharging extraordinaire Banks Power, Dallenbach will be fielding a monstrous 1,307-horsepower rocket, making it the most powerful car - as far as output is concerned - amongst the entrants in the Unlimited Class. Will all those ponies prove enough to topple the mighty Japanese? Well, if there's one way to do it, adding some much-needed juice to your car is certainly not a bad idea.

Jean-Philippe Dayraut/850-horsepower Dacia Duster "No Limits" race car

Another contender is Jean-Philippe Dayraut and his fully tuned Dacia Duster "No Limits". As the name of the racer clearly suggests, Dayraut is going no limits for the race and to help him in his quest of winning this year's Unlimited Class, he's bringing along the Nissan GT-R-powered Dacia Duster that produces a staggering 850 horsepower.

Dave Carapetyan/Specially modified Mitsubishi Evolution

Then there's Dave Carapetyan - the three-time Pikes Peak Open Class champion who is taking his talents over to the Unlimited Class - and his boys over at Rally Ready Motorsports. These guys have been busy preparing Carapetyan's Pikes Peak racer, a specially constructed Mitsubishi Evolution 959 that carries a 2.3-liter 4G63 inline-four engine.

Who takes home the title this year, and who has the best shot in breaking the 10-minute mark? All that will be answered when the 2011 Pikes Peak International Hill Climb opens on June 26.

Plenty of Racers, Plenty of Classes

In addition to the Unlimited Class, the 2011 Pikes Peak International Hill Climb also offers plenty of other class-competitions. A total of 194 racers have signed up for this year's event and all the classes are expected to get some pulse-pounding action, including the return of all the defending champions in each class. Check out all the classes, together with a brief description for each and the names of the defending champs.

Super Stock Car

Looking a lot like stock cars, the competitors in this class are driven by the need to be the best in their group, for obvious reasons. Cars here are similar to NASCAR racers for their emphasis on speed and safety with the engines more often moved backward to give the cars better handling than all other stock car counterparts.

Defending Champ: Clint Vahsoltz

Open Wheel

One of the oldest and quirkiest classes on Pikes Peak, the Open Wheel Class has been around since the first installment of the event back in 1916. Cars here are usually not reserved for a particular type, hence the 'open wheel' designation. Over the years, there have even been Indy car-style race cars and dune buggies competing for the Open Wheel record, which, by the way stands at 10:05:85 set by Robby Usner back in 1994.

Defending Champ: Spencer Steele

Vintage Race Cars

Don't be fooled by the 'classic' nature of these cars, because despite their age, they still run pretty good. Good enough, in fact, to complete a whole lap of the "Race to the Clouds". As part of the eligibility, only cars that are "manufactured in 1980 - with a pre-1981 powerplant or drivetrain - or earlier and carry a body, frame, and chassis that are correct for the date of manufacture" are allowed to compete in this class.

Even then, it must also be noted that "automobiles with pre-1981 racing history shall be admitted preferentially to those without this history".

Defending Champ: Keith Davidson

Time Attack

This division is one of the more popular classes in Pikes Peak, in part because a lot of popular drivers have taken to racing in them. It's divided into two classes for production based two and four wheel drive vehicles with some of the notable participants including Jeff Zwart and the legendary Rod Millen.

Defending Champ (2WD): Jeff Zwart

Defending Champ (AWD): Jeff Denmeade

Motorcycle 250 CC

It may be the smallest motorcycle engine class on Pikes Peak, but these 250cc riders are as fast as they are competitive. Bikes participating in this class are usually factory built for racing with two-stroke single-cylinder engines and four-stroke single-cylinder.

Defending Champ: Davey Durelle

Motorcycle 450 CC

It's the Class A popular class for motorcycle riders that involves two-stroke and four-stroke engines. Single and twin-cylinder engines are likewise allowed, with no strict compliance on model year. Older bikes all the way to those that just came from showrooms are eligible.

Defending Champ: Joe Prussiano

Motorcycle 450 CC Supermoto

This class is similar to the 450 CC Class except that it's limited to four-stroke, single-cylinder motorcycles with a maximum of 17" wheels. If you wanted to be technical and matter-of-fact about it, the bikes allowed in this class are almost as powerful as that participating in the 750 CC Class.

Defending Champ: Leeland Sinclair

Motorcycle 750 CC

For bikes that have engine that creates excellent power-to-weight ratio, the 750 CC Class is the way to go. Riders competing in this category usually choose lightweight, single-cylinder, four-stroke 700cc engines with an option to choose twin-cylinder 750cc engines.

Defending Champ: Gary Trachy

Motorcycle 1,205 CC

The biggest and most powerful motorcycle class in Pikes Peak features over 900cc twin-cylinder off-road motorcycles, giving the event more than enough of these thundering machines to make it one of the more popular and memorable bike classes in Pikes Peak.

Defending Champ: Greg Tracy

Motorcycle Quad Modified

Mostly featuring ATVs, or four-wheeled motorcycles, eligible machines are limited to the tread width of the tires and the use of engines that carry 500 cc or less. For this particular class, added emphasis is placed on stability to account for the rapid shifts in weight by the riders.

Defending Champ: Michael Coburn

Motorcycle Sidecar

A tag-team effort in Pikes Peak, if there ever was one. The Motorcycle Sidecar Class features two riders in one sidecar. One serves the purpose of being the driver whereas the passenger, otherwise known as 'the monkey', is responsible for balancing the weight of the sidecar in steep corners. It's one of the most popular classes in all of Pikes Peak.

Defending Champ: David Hennessy

Electric Auto Exhibition Powersport

This particular class is reserved for those vehicles that "demonstrate advancements in the practical application of motor sports technology". It's pretty much a free-for-all in terms of eligible cars, as long as it doesn't fit into any of the regular divisions.

Defending Champ: Ikuo Hanawa

Pikes Peak Open

Another popular class that with cars that take the form of stock cars from the outside, except that they've undergone a lot of modifications on their engines, transmissions and suspension, among other things. Sometimes, racers who participate in this class move up to the Unlimited Class afterwards.

Defending Champ: Dave Carapetyan*

* Carapetyan has moved up to the Unlimited Class so you can expect a new champion crowned in the Pikes Peak Open Class.

Unlimited Class

As what we've already mentioned, two words best describe the Unlimited Class: anything goes.

Defending Champ: Nbuhiro "Monster" Tajima

The Return of the Legend

Another interesting element of the 2011 Pikes Peak International Hill Climb is the return of the 'King of the Peak', none other than Rhys Millen's father, Rod Millen. Having been absent from Pikes Peak competition since 1999, the elder Millen is nevertheless considered as one of the most famous participants of the event, having won the Unlimited Class title five times and holding the overall record for 13 years before Tajima broke it in 2007. This year, Rod Millen will not be participating in the Unlimited Class - Rhys will do the honors there - but he will instead get behind the wheel of his son's Hyundai Genesis in the 2WD Time Attack against defending champion, and good friend, Jeff Zwart.