Go Karts and Karting, Cheap Track Day Alternative
By Mike Kojima
What do guys like Billy Johnson, Dai Yoshihara, Joon Maeng, Tyler McQuarrie and other Pro Drivers do to keep sharp in between events and during the off season? Karting. We know that most of you like track time, however track time is a precious commodity that is getting harder to come by in this sluggish economy. As we get older, family and career commitments take away more and more time that used to go to race car maintenance and prep. Some of us move out of family garage space and have less room in apartments and condos. All of these factors make owning a race car more and more difficult.
|Our Intrepid Silverstone TAG kart was updated with 2010 bodywork. The Silverstone was a 2008 model that we purchased used on craigslist. The Silverstone chassis is made of tig welded 32mm chrome molly. The larger diameter 32mm tubing is better suited toward lower grip American tracks and stouter (Fatter) American drivers. European spec karts are usually designed for more flex and stickier more groomed European tracks with jockey like Euro drivers. Karting is a serious business in Europe, the top drivers make six figures and factory teams race for TV and lots of spectators. Many F1 drivers got their start in karting.
|Even though our kart is an older 2008 model, it would still be competitive in racing as the main difference between it and the 2010 model is that the side pod bumper tubes are not floating on teflon bushings and the camber/caster adjustment is only 4 way vs the newer karts being 6 way. At our level this is probably not even a feelable difference. Christa and I disassembled the kart after buying it used. The frame was powdercoated by Embee Performance. Embee also did the high temp coating on the exhaust system. Christa spent a lot of time cleaning and polishing all of the CNC billet parts that this kart has. The wiring and plumbing were also redone for a cleaner look and greater reliability.
If you have the will but not the means, all is not lost. A lot of us are discovering that Karting is a really good and economical alternative to automotive motorsports. Karts are fast, really fast and probably more challenging than racing sedans to get around the track quickly. They are capable of pulling over 3 lateral g’s in cornering and can reach speeds of over 100 mph on some courses.
|The two stroke 125cc Parilla Leopard engine was freshened with new rings and given WPC treatment on the piston, cylinder, wristpin and rings. The expansion chamber exhaust was treated with Embee thermal coating which widened the powerband noticeably. The engine produces around 28-30 hp and is watercooled. It uses a spec clutch which saves a lot on the expense of clutch tuning. Clutch tuning is a major factor in some classes and for TAG, the rules take this out the equation which eliminates a lot of fiddling. It is not legal to modify the engine or any of its systems. Only rebuilding and some blueprinting is permitted. The engine is run on VP 98 race fuel and Motul synthetic Kart engine oil is pre-mixed at a 30:1 ratio. The Motul is smokeless and burns extra clean.
|Late model karts have 50mm rear axles and three bearings supporting the axle. 50mm axles work better for finding traction with heavier more powerful karts. In karts the axle is an important tuning element of the chassis and it is available in several different stiffness levels. The stiffer the axle, the more rear grip you have. Too stiff of an axle and the differential less rear end will scrub and cost you speed. The water pump is driven off of the axle. The axle is adjustable for ride height and track width. The higher the ride height, the greater the bite, the more narrow the track, the greater the bite as well. Too high and too narrow you get corner exit drag and hop in mid corner. The axle carriers are CNC billet and all mounting hardware has been upgraded to hard to find metric stainless from Baller Bolts. We were getting tired of keeping our black oxide and chromate bolts oiled and clean. Stainless really reduces maintenance and the bolts are never rusted or seized like they sometimes do in aluminum due to the different galvanic conditions of the two dissimilar metals. We also cleaned up and simplified the wiring and plumbing. The previous owner was not so neat at this.
Karts are compact and easy to store, they are also much easier to work on than a car. The costs of maintenance are much lower and the cost of entry can be lower as well. If you pick the right class, or if you are a casual driver, you can nurse a $160 set of tires for a season and engine servicing for a couple of seasons. A professional engine blueprint/rebuild is often less than $1000. If you want to race competitively, then you must change tires and service the motor more frequently but the prices are a fraction of what the same costs would be on a race car.
|A KG Cobra Head ram air box was used. The black velocity stacks are the class mandated restrictors that act to limit power. The Cobra Head intake uses ram air to get the most air past the restrictors at speed.
|The rules require a chain deflector to protect the driver from a broken chain. We used a Noonan Racing carbon fiber deflector. We also used a Reginia O-ring chain. O-ring chains are a lot stronger but can suck a little power. That’s why they are usually only used for the more powerful classes. Motul synthetic grease was used to repack the bearings. Motul Protect is used to keep raw parts like the rear axle from rusting. The third bearing set screws are not run to allow more axle flex in our application to free up the chassis on corner exit.
A new state of the art racing kart can cost from $5000-$10000 depending on what class you choose but that is a fraction of the cost of constructing a race car. Used but still very serviceable karts can be found for as little as a few hundred dollars with good used and competitive examples going for about half the price of a new kart.
|The Tilllotson Diaphragm carb uses crank case pressure pulses to move fuel from the tank to the carb. The Parilla engine is notorious for breaking throttle cables due to a funky cable routing in stock condition. We cured this with a Burris cable relocation kit.
|The spec pipe cannot be modified but we gave it the Embee thermo barrier coating treatment which seemed to actually broaden our powerband. Keeping the heat in the pipe makes the scavenging pulses stronger. The hydraulic brake uses a vented and fully floating rotor on a CNC billet hat, just like a big car!
|A TAG kart is self starting with an electrical system and a battery. Starting is push button convenient, one of the reasons why we love TAG karts. Other people do too, TAG karts are now probably one of the most popular karts for senior classes. The cool thing is that this is making used HPV, KT100 and even shifter karts cheap and plentiful on the market. You can also see the frame’s adjustable third rail which tunes bending stiffness. This affects the amount of wheel lift and drag on corner exit. Lighter drivers usually prefer to leave it out or with very little tension. We prefer it in with a slight amount of tension.