Autocross 101

It’s a sign of the times when you see more and more people interested in something different from the norm. In some cases interest can be gained through a resurgence of an old sport or hobby, which in turn cements the theory of what is old is new again.

 

Autocross

In the automotive world the pro-touring movement has gaining a huge fan base, where high-end builds are being lead towards high performance use. This movement has been seen mostly in the Muscle car circles for close to the last decade or so, and owners of these vehicles, thrive on building their old Camaro, or Mustang to out perform some of the greatest super cars that have ever been build. This has all been made possible through the latest technology from aftermarket manufactures, where it’s never been easier to accomplish.

 

Trucks also have been involved in this movement as well in fact surprising many hardcore muscle car aficionados who don’t believe that a truck can perform as well as a car. We all know that a truck was designed to haul weight in the back, thus by design truck’s are at a disadvantage from their inception as far as navigating thought corners. Car guys love to remind us truck guys of this handicap, so it’s great to see a fast truck give them a run for their money, which in turn the sport has seen a number of resent upsets.

 

In an effort to legitimize the Pro Touring movement have turned to a competition style called Autocross which by no means is anything new, as the sports roots can be traced back to the early proving ground days of automotive manufacturing. If this sounds familiar to you it probably is as one of the longest running automobile clubs in the United States (SCCA, or the Sports Car Club of America) holds monthly events throughout the U.S. at local tracks and sometimes even in parking lots.

 

So what is Autocross you might ask? According to Wikipedia the definition is a timed competition where drivers navigate one at a time through a defined course on either sealed or unsealed surfaces. They go on to add that autocross differs from road racing or oval racing that generally there is only one car on the track racing against the clock rather than a head to head contest. Seen as entry level motorsport, it tends to place more emphasis on car handling and driver skill rather than sheer horsepower. Courses may be temporary, marked by traffic cones where speeds usually don’t exceed highway speeds, but the activity level (measured in discrete turns per minute) can be more diffcult than Formula One racing due to the large number of elements packed into each course.

 

Interest in these events has been on the rise as more and more SCCA event locations have been added, as well as some other sanctioning bodies such as the Goodguys Autocross Challenge, the American Street Car Series events, and many other local level events seen at most car and truck shows.

 

Sounds fun right? So how do you get involved in something like this and can my truck be competitive? We asked the same questions and looked into how to get in on the action. Take it look at what we found and see if you too can join in on the fun.

 

Autocross

Tip 1: SAFETY FIRST

 

 

Seats

Seats:

 

A seat that contains the occupant is the best suited to actully help the driver with his or her driving. Such an example is MasterCraft Safety’s model 3G which is ideal for the track however if the truck is to be used as a daily driver as well as for track use, the higher seat bolster can be cumbersome and may block some of your rear vision while backing out of a parking space so take this into consideration. However, hands down, the benefit of using a seat like the 3G provides excellent shoulder protection, hip containment, and the seat belt slots for the lap and anti-sub belts. Most experienced drivers will agree that the best place for your seat to be located to ensure you the best control is positioned far enough forward to have your leg slightly bent when its on the clutch or brake pedal while the seat-back is reclined or upright to a position that allows you to rest your wrists on the steering wheel while you shoulders are firmly against the seat.

 

Seat Belts

Restraints (Seat Belts):

 

It’s recommend by most sanctioning bodies that a minimum of a five point belt system, manufacturer certified to the SFI 16.1 specification should be used however, it depends on the series rules and requirements and every series is just a little different. For most sanctions, either fastening mechanism (latch and link or cam–lock) should be acceptable for auto-cross.

 

When it comes to hardware, the adjuster mechanism on the shoulder harnesses can be the traditional style or something new like Mastercrafts’ QSR style (quick safety release). The benefits of Mastercrafts’ QSR series is the ease of adjustment which is handy when multiple drivers are in and out of the vehicle. Another fearture is the webbing where some companies use nylon and others use polyester. There are benefits and drawbacks to both materials but most manufacturers nowadays are using exclusively polyester because there is less stretching during an event (aka crash).

 

Restraint mounting points are VERY VERY important, and if your not sure how to install restraints the right way, MasterCaft’s website contains detailed instuctions on how to mount all the belts into your vehicle. The biggest mistake most installers make is where they mount the shoulder harnesses, as they should not be mounted lower than 10 degrees below the shoulder line. Any further down and in a roll-over situation, you could break your collar bones, ouch!

 

 

Helmet

Helmet:

 

You may need to check with the sanctioning body first to see what helmets are on their approved list as all helmets have an expiration date for safety purposes. If you’ve never owned a helmet before, a helmet like the 1320 from Impact is the answer for the racer looking for an entry-level helmet without sacrificing any safety whatsoever. The 1320 is affordable but does not cut any corners on quality or safety. It’s maunufactured by hand with the same exact standards as the rest of their elite lines of helmets and features all of the high quality options including their fire-retardant, variable density, single-piece Gray Matter helmet liner, plus interchangeable sizing cheekpads, along with a fire-retardant Kevlar chinstrap with dual D-Ring closure and a 1/8 polycarbonate shield with three-position detent.

 

Autocross

TIRES

Tip 2: TIRES

 

Most of us have heard Robert Duvall tell Tom Criuse in the movie Days of Thunner that tires win races which he preachs the truth, so worn out, old tires will get you no where. Just about every tire manufacture makes a tire suited for autocross or for that matter, high performance driving. One key thing to look for before you purchase new rubber are the rules that apply from the sanctioning body that are approved to run at the event(s) that you plan to compete in. In most cases, the tread wear rating is the deciding factor as this rating determines the compound of the tire. In most cases, a 200 tread wear or above rated tire is acceptable, however a higher rating usally means a harder compound that can lead to less grip of the road. Another thing to remember is that a softer compound tire means a shorter mileage lifespan, so be selective in your choice based on yout racing to cruising ratio.

 

Tires can be helpful in judging camber and proper inflation by running a few laps and heating the rubber up and then using an infrared tempurature gun on the edges and center of the tire, using pre run temps as a baseline. An overly hot center temp means too much friction caused by over inflation. To high of temps on the edges show the need for camber adjustments. The same can be said by the opposite of too low temps. Make the adjustments and test again.

 

Street Truck

Street Truck

Street Truck

Tip: 3 SUSPENSION / BRAKES / CHASSIS

 

 

Street Truck

Street Truck

Street Truck

Suspension:

 

If this seems like it my be fun to you and you want to try it out then the best advice we can give you is to make sure that your suspenison and brakes are in good working order before going to the track. Belive it or not, even some stock suspension parts and or brake systems are good enough for the beginner, if they are in good working order. It’s only obvious though, as you progess your trucks suspenison and brake system will need upgrades. Areas in which will need improvements are shocks, springs, steering parts, and anti sway bars. Depending on your model you may need to add or convert to a different type of suspenison such as the case with rear end handling where adding a rear anti sway bar, or a different type or the addition of a link-style suspension will help cure a trucks’ handicap.

 

Street Truck

Chassis stiffness will make a difference in performance driving, however for street use and track use stiffer is not always better as the stiffer the chassis the harder the ride so try to find a balance if you plan to continue to cruise it as a daily.

 

 

Street Truck

One of the most overlooked conponents that one makes the mistake of not addressing is body mounts including the cab and bed mounts. Take for example, you would play basketball in a pair of wing tip shoes compared to a pair of basketball hightops? The same goes for body mounts. Body roll, or cab sway can be conquered by replacing the factory rubber mounts with polyurethane bushings. Also don’t forget about your suspension bushings, where polyurethane bushing will reduce compontent flex rebounding the forces back to the tires.

 

Street Truck

As far as brakes are concerned more clamping force, and better cooling are some obvious factors, however, the ability to control the amount of force applied to the front or rear tires is called brake bias which can prevent not only the tires from locking up and skidding, but can be used in conjunction with performance suspension parts for tunning purposes.

 

If you plan on adding a roll cage, be sure to tie it into the chassis and triangulate as many mounting points as possible. The strongest structure is the triagle where as energy chases it around the shape when stressted. This not only will ensure more safety, but add some rigidity to your chassis as well.

 

Street Truck

Street Truck

Tip 4: VEHICLE BALANCE & WEIGHT

 

Knowing how much your truck weights is an important part of setting up your suspenison. Knowing where the weight is or where it needs to be moved is the first step in tunning your suspenison. It’s common knowledge that all trucks are at a disadvantge when it comes to weight balance. I’m sure all of us have experienced the back end of the truck -bed trying to swing around us while cornnering in the rain. To combat the terrible traction problems that a truck is born with, we need to foucs on it’s weight balance ratio. Again we know that a truck is front end heavy that makes most people think about adding weight to the back, which is only half true. In reality, one should look at the weight of all vehicles at all four corners, thus the term corner balance. Why is this important you ask? Corner balancing neutralizes the effects of weight shift by equalizing the weight between the opposing corners.

 

Street Truck

The closer to 50/50 front to back weight ratio the better it will transfer weight during a turn. This also helps in straight line traction as well, as the truck will launch forword rather than spin the tires if the weight can be transfer forward. So how do you find out and change the weight in all the corners? The use of a four corner scale system, will give you the lowdown on what your truck weighs in the corners. After your armed with that info, you can begin by moving some items in the vehicle to the area that need more weight, like moving the battery behind the passenger side of the rear tire, or can even help you tune adjustable suspenison parts such as coil over shocks, and even pre-loading items including anti-sway bars, or adjustable link bars.

 

Street Truck

Street Truck

Street Truck

Street Truck

Street Truck

Tip 5: TOOLS

 

Every form of motorsports has a set of specailized tools that are required to help you succeed. Autocross is no exception to this rule and while it’s important to have your truck running the best it can, at the track you’ll need to foucs and the chassis more than the drive-train. A few must haves for the beginner are a good tire gauge, a stop watch, some chalk, an infrared thermometer gun for measuring tire temperatures, and something to fill the tires with (i.e. a supply tank, or a small compressor.) Oh and don’t forget, a pen and a notebook to keep notes! These are the essentuals to running at any event, and will help you to progress.

 

As you get more confident, a few measuring items need to become your traveling buddies, as a caster/camber gauge, (either a stand style, or hub mounted), a pack of alignment shims, and a measuring tape, will get the job done. Before the track, a set of computer scales will award you with a wealth of knowledge for your setup. If you’re running coil over shocks, then a spanner wrench will be a purchace as well. A video camera on your truck such as a Go Pro or Replay will allow you to review the last run from the drivers perspective, however, someone videoing your run will give you a better idea of what your doing right, and what your doing wrong. Mophie has recently introduced their Outride iPhone mount system allowing you to use your phone to capture video safely giving you instant review and sharing capibilities track side! Most imporant though is your brain, pay attenion to other drivers, and remember to keep notes that will help you the next time that you’re out.

 

Street Truck

Street Truck

Street Truck

Street Truck

Tip 6: DRIVING

 

Yes it’s cool to watch a professional driver guide a vehicle anywhere that he or she wants, and I know that we all think that we can to the same thing but in reality we can’t. Practice or seat- time is the best way to get fast, and most of us think that sitting in traffic means that we have done our fair share. The most important thing to remember is to focus on the coruse. Look ahead, and be aware of the next turn before you enter the one right ahead of you. If possible, walk the course or even help set it up in the morning and try to draw a mental picture of it in your mind. Last but not least slow down, don’t try to over-run the course! You’ll be surprised by your time if you just relax and drive the course calmly, try to remember that smooth is fast. Plus ask questions, or even for a ride as a passenger (usally to a driver who is not in direct competition with you) or watch others run the course and take mental notes.

 

Sources:

 

MasterCraft safety: www.mastercraftsafety.com

Impact Safety: www.impactraceproducts.com

Nitto Tires: www.nittotire.com

No Limit engineering: www.nolimit.net

Ride Tech: www.ridetech.com

Hotckis Performance: www.hotchkis.net

Wilwood Brakes: www.wilwood.com

SSBC: www.ssbrakes.com

Hellwig: www.hellwigproducts.com

Longacre Racing: www.longacreracing.com

SPC Perf: www.specprod.com

Viair: www.viaircorp.com

Energy Suspension: www.energysuspension.com

Go Pro: www.gopro.com

Replay: www.replayxd.com

Mophie: www.mophie.com

 

Events:

 

American Street Car Series americanstreetcarseries.com

Goodguys www.goodguys.com

Optima Ultimate Street Car Invitational www.optimainvitational.com

SCCA www.scca.com

Silver State Classic Challenge www.sscc.us

So Cal Challenge www.socalchallenge.com

 

Text By Marcel Venable

Photos by ST Staff

 

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