HARLEY
RACING 101PT2 NITRO VS PRO GAS BIKES By : Billy Doherty
Everyone likes to hear the roar of a Nitromethane Harley starting up and especially going down the track . Watching the driver moving around on the bike to keep it straight going down the track . The driver looks like he has his hands full and is crazy diving that monster down the track . The nitro bike is truly a fire breathing monster .
Top Fuel Harley are close to a 1,000 horsepower out of 2 cylinders . The front wheel is carried almost the full length of the track . The driver is moving their weight around on the bike to help steer the bike because the front wheel is up and the bike is on the rear wheel and wheelie bar . Six seconds later the parachute is deployed at over 200mph . Not really to slow the bike down but to help keep the bike straight while not under power .
Top Fuel has fuel injection and can have 2 speed transmission or high gear only . It also has computers that collect data and help adjust when the bike leans out and how much going down the track . You will need several people to help .
Pro Fuel Nitro Harley are over 500 horsepower and will carry the front wheel to just past 1 / 8 mile and set it down . It is less violent through the whole ride . Pro Fuel has a carburetor on it and has timers on it to lean it out going down the track . It has high gear only . It does not have a parachute on it because it only reaches speeds of 170 mph in seven seconds . The computer on this bike is for data . You can get away with the rider and one other person working on this bike .
Both bikes have no clutch lever . The levers up on the handlebars is front and rear brakes . They both have similar clutch set up that have weights and springs to act like timers for the clutch so that it will not go to full lock up right off the launch . Most of the racers have a clutch grinder because the steels in the clutch have to be changed or reground between every round . The oil has to be changed ever round . Most of the engines can be rebuilt between each round if need be . The bikes are basically at idle at launch and the driver has to react with his throttle hand to launch the bike . Both have a lot of maintenance between each round . There is usually a hour and a half between each round to get it all done .
Basically Nitro Harley ’ s you crack the throttle wide open , hold on , do your best to steer the beast down the track . Sometimes they have a big fire explosion at the beginning of the race to not far after the launch .
Pro Gas Harley ’ s starts up but are not as loud . The driver of the bike has to be precise on the start . Letting the clutch out and not letting your hand fall off from the launch . The wheel is up in the air till you shift gears and then it comes back up again on each shift . You will have to shift the bike four times when the shift light comes on . You are trying to be precise on each shift while trying to see where you are at on the track . The whole time trying to shrink yourself so that you will have as much of your body behind the fairing to stop wind drag to go faster .
Pro Gas Harleys are 250 to 350 horsepower and are mostly carbureted and some fuel injected . The bikes will weight with rider about 650 pounds . The clutch on these are similar to nitro but different . They usually will last several races to a full season . The clutch has springs and weights so that you can adjust the launch and how the clutch comes in for each track . The bikes have computers mainly for data . Usually not a whole bunch of maintenance on the bikes between rounds just fine tuning to get the most out of the bike at that race . Some pro gas classes have a 10 ” or a 7 ” rear wheel . You can get away with just one extra person to help with this bike .
Nitro and Pro Gas classes are expensive to run and keep the maintenance up . Neither are for the faint of heart . You better be on your game or you will get in trouble .
Always remember the bigger the bomb the shorter the fuse !
4 Thunder Roads Magazine Louisiana / Mississippi | August 2018 | www . thunderroadslams . com