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  • Writer's pictureSatvik Khuntia

The car with 11000 HPs

Updated: Apr 1

The National Hot Rod Association (NHRA) like every year brought its iconic Flav-R-Pac under the majestic shadow of Mt. Rainer at Pacific Raceway in Kent, WA. What caught my eye was a flyer that read “Nitros Funny Car, 11000 HP”. 11,000 Horsepower. After rubbing my eyes and pinching myself I knew I was not reading it wrong. I knew I had to go see it. I ended up not just experiencing the shudders from the straight piped hot rods launching 50 feet away filling your heart with exuberance and lungs with carbon monoxide but also gave me a peak into the world of drag racing.


Before I start talking about all the different drag races I got to see for myself, I want to address the elephant in the room. 11,000 Horsepower. To put things in perspective, the most sold car in the US in 2022 is a Toyota Camry, in India it's the Maruti WagonR and in Europe, it's Peugeot 208. The top trim of all these vehicles can produce a maximum horsepower of 301, 88.5 and 130 respectively. This is the amount of power most people in the US, India and Europe are using. An F1 engine in 2023 produces 1050 horsepower and the crazy supercar Koenigsegg Gemera produces 2300 horsepower (1400 from the inline 3). So where does this insane 11000 hp come from?


The key contributing factor to this insanity is fuel. It is 90% Nitromethane (or Nitro - CH3NO2) and 10% Methanol (CH3OH) which has its O2 from the chemical formula and doesn’t depend on air for the necessary O2. This helps in reducing the air-fuel mixture from 14:1 for gasoline engines to nearly 2.5:1.  This means you would need a lot less air to produce the same horsepower or about 8 times the power with an equivalent supercharged gasoline engine. Speaking with an engineer from one of the teams, I found out that if the same engine is built for gasoline, it could make 1800 hp. Which is impressive by itself.

The 8.2L V8 Chrysler engine as a single aluminium block comes without a cooling system. The cooling properties of the fuel as well as the one-time 10-second operation of the engine eliminates the need for a water jacket. To give a taste of the intricacies of what goes on before a 10-minute race - the thickness of the copper head gasket on the engine is decided only a few hours before the race and is based on the day's weather forecast. The reason to care about this is because the gasket dictates the compression ratio and hence the power during the race.


Now that we have established that the air-fuel ratio is rather low, which means, a lot more fuel will be needed for every combustion. To supply the fuel that is needed, the fuel is injected continuously at the rate of nearly 78 Liter per minute Which is why 1 race can consume nearly 15 gallons of fuel which is equal to 1 tank of fuel on a regular daily driver's car. That is all for a quarter-mile race where they reach a max speed of more than 300 mph within 4 minutes.


The pressure inside the cylinders due to the combustion is so high that it is enough to cause the pistons and the connecting rods to shrink up in a couple of runs. Hence sometimes they last only for a couple of races. The combustion doesn’t end inside the cylinder either. This is due to the slow-burning nature of nitro fuel. This is the reason why you would see fire at the exit of the exhaust pipes. The unburnt fuel gets in contact with the oxygen in the outside air and combusts. The funky upward-facing exhaust while looking cool solves another purpose. It provides an additional 1000 pounds of downforce AND a bit of boost. But this is not enough to keep the car grounded. It the rear spoilers that add 12000 pounds of downforce along with the front wings adding 2500 pounds. Crazy.


But how is the 11000HP measured? Typically measurements are done on a dyno for a traditional engine. But this engine is not cooled and operates at high power generating high heat and hence has a short life of operation of 10 seconds. Not enough for a dyno to measure. Power is instead calculated using torque sensors, speed sensors and road conditions.


The power produced by the engine is no good without the right tyres. Goodyear officially sponsors these top fuel dragsters with what are called rippled wall tyres. These are soft compounds bolted with a rim with 24 bolts. The 17-inch wide, thin and 15-inch wide sidewalls and 10 psi pressure in the tyres, help create a contact patch of almost 250 square inches as compared to nearly 130 square inches for a regular 4000-pound car. The twisting of the tire also impacts the final drive ratio as the diameter reduces while delivering the torque. At high speeds, these tyres expand increasing the final drive ratio again due to centrifugal force delivering an even higher speed. Because of the unique operation of these vehicles, they do not have a transmission but a single use multi-plate clutch for direct drive and a reverse gear which is good for 2-3 runs.


Race Day


On the race day, you want to make sure everything goes right with the car. The engine is built on the site for most teams since a lot of race day weather conditions impact the tolerances for the supercharger intake and head cover gasket thickness. Likewise, at the end of the race, the complete engine is torn down, and each element is inspected. At the first start-up of the day, the engine is started on Gasoline to get the engine up to temperature following which the engine is started and run only on nitro fuel. Each morning when the engine is assembled, the cam timing and mag phasing are adjusted. Getting the engine calibrated, it is ready for the race.


A lot of the locations provide day/night testing. The vehicles before the race are subjected to technical inspection on any leaks/ secured battery/ seat belt/ safety gear. Passing the inspection the vehicles are given a competition number. The race batches are divided into class/ types of wheels (slicks vs street) / type of tree (sportsman or pro) and the vehicles are placed accordingly on the lanes. On getting to the tracks drivers are advised to turn off the AC to avoid water on the track. The tyre pressure is lowered by 4-5 psi to increase the contact patch on the drag strip. This is also why you see the bending of the tyre wall at launch.


At the start of the race, the drivers do a burnout. There is always the risk of overdoing a burnout which can be different for the different vehicle classes. This is mainly to clean the tyre surface and get it up to temperature for optimal traction at the launch.


After the run, the engine is torn down, the head is cleaned, and inspected for any damage to the spark plugs clean the head. In each race, the heat at the spark plug is equivalent to the heat produced during welding. Spark plugs usually last not more than a couple of runs. The pistons and piston heads are subjected to high pressures that they shrink in length and size after every race. Before the engine is used again, this change in the dimensions of the engine components is taken into consideration while calibrating the engine. The clutch is also inspected. The clutch plates usually last for not more than 1 run, maybe 2 on a perfect day. The casing, however, stays longer than a few races. The tyres are also subjected to inspection after races. The engineer looks for thread-like pieces coming out or holes which usually are heat marks causing inconsistent surfaces. At the end of the day, typically not more than 3 or 4 races, the entire vehicle is stripped down and fully torn down for a chassis inspection for any cracks.


Types of drag races:


NHRA identifies 4 categories of drag races as professional categories. These are Top Fuel, Funny Car, Pro Stock and Pro Stock motorcycles.


Top Fuel



These are the absolute giants in the game chugging 15 gallons of Nitromethane to produce 11000 hp to cover a quarter-mile drag strip in under 4 minutes. Top Fuel dragsters weigh about 2300 pounds and are 25 feet long and rear spoilers that sit 4.5 feet high.


Funny Car



Put a carbon fibre production car-looking body on a shorter wheelbase compromising just 0.1 or 0.2 seconds of a quarter-mile drag strip you would get a beauty called Funny car.


Pro Stock



These are production automobiles on steroids. A huge identifier for this class is that the chassis is a four link rear suspension, and the engine and body should be manufactured by the same company. These don’t have any form of forced induction through turbocharging/supercharging or Nitro fuel. They are run on race-grade octane. They are made to produce about 1400 hp to cover a quarter-mile drag strip in about 6-7 seconds.


Pro Stock Motorcycles



Similar concept and HP as the pro stock, these are highly modified vehicles that can run northwards of 200 mph covering a quarter mile in under 7 seconds. They feature in line 4s from Kawasaki and Suzuki models and V twins from Harley Davidson to name a few. This insane speed and acceleration are owed to its lightweight and aerodynamic design.


There are other categories like Top Alcohol - which runs on dominant Methanol-based fuel with slight flexibility in choosing between a small proportion of nitromethane in the fuel supercharging the engine; Pro Mod – which features Mustangs, Vipers and Corvettes; Top Sportsman – which are full-bodied vehicles making the quarter-mile drag strip within 8 seconds.


References




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