How Dragster Tyres Accelerate to 335 MPH in 3.6 Seconds

top fuel dragsters have the same power as 12 f1 cars drink as much fuel as the 747 at takeoff and their drivers experience the same g-force as astronauts did on the space shuttle all that power means the tyres have to be pretty special to get the car from zero to almost 320 miles an hour in under four seconds but how do these specialized tyres help the dragsters pull four and a half g under acceleration why do they wrinkle like this and how did draxes reach such incredible speeds all of that coming up we know the standard recipe for going really fast plenty of power minimal weight and a lot of grip the top fuel dragsters are the fastest class in drag racing and so take each of these factors to the extremes and that's why top fuel dragsters are the fastest accelerating machines in the world they use chrysler hemi 500 cubic inch blocks with some extreme modifications working out at over eight liters of displacement they are also heavily supercharged use specialized drag fuel and have spark plugs that are so powerful you could use them as arc welders this all means they can produce around 11 000 horsepower and drink 11 gallons that's 50 liters of fuel in a single run burning all that fuel produces so much noise that two cars were once measured at 2.3 on the richter scale the engines are under such huge stress that the teams have to completely rebuild them for each run replacing things like pistons rods rod bearings and the crank incredibly the crews managed to do all of this in under two hours between rounds so why do the tyres crinkle at launch they are called ripple wall slicks and run at very low pressures to maximize grip by having the tyres at about 7.5 psi around half a bar the tyre squats when applying the engine's torque at launch this flattens the bottom of the tyre increasing the size of the tyre's contact patch improving grip and providing a better launch the crinkling actually reduces the instantaneous torque off the line but means the driving force is applied more gradually leading to reduced wheel spin applying the force more gently provides better traction similar to how a smoother throttle application in a race car can lead to better acceleration out of corner when compared to smashing the throttle and causing wheel spin the crimpling is a side effect of the huge reduction in the tyre's diameter it's often called folding of the tyre and needs a very specific tyre pressure to achieve optimal grip the governing body for the sport the nhra actually regulates the minimum pressure teams can run this is after some teams began using less than 5 psi about 0.3 of a bar which provides a larger contact patch and more grip but can cause a tie to explode or simply be ripped off the rim at higher speed the squat of the tyre serves another purpose as it reduces the overall drive ratio of the car as the diameter of the tire gets smaller the effective gear ratio is reduced a bit like changing down a gear this provides better drive and acceleration at launch the tyres can compress by up to 8 inches in diameter reducing the gear ratio by about 20 percent what's even more impressive is how the tyre stretches under centrifugal force at high speed you can see this best when the drivers do burn out before the run it's called ballooning and serves a couple of purposes opposite to the squat effect is when the tyre stretches out at higher rpm this increases the drive ratio of the car and leads to better top end performance when at high speed the squat and the balloon effect means that most top fuel dragsters use a single drive gear and don't require gearboxes the drivers describe it as being up on the tyre and it's like changing gears the tyre's ballooning also leads to the contact patch the area of the tyre touching the surface narrowing and reducing the roll and resistance of the tyre thanks to their size and extremely sticky soft compound this can have a big effect at high speed so what compound is used for the tyre dragsters used an extremely soft compound fast softer than even the softest f1 compound this means they produce more grip than a harder tyre and get up to temperature much faster for a mother race series we know that a softer compound leads to more grip and more performance but why while tyres produce grip through adhesion in simple terms this is the force needed to overcome the sticky chemical interactions between the tyre and the road rubber is used in tyres because the compound can conform to the surface of the road getting into the rough surface this increases the surface area of the tire that is in contact with the asphalt and allows more force to be applied without sliding however it does mean rubber can shear off when in these cracks this is why softer tyres don't last as long because more rubber is removed when applying force through the tyre this stretching of the rubber creates heating effects as the rubber molecules rub against each other explaining why softer tyres heat up faster on the flip side this leads to tire degradation where the rubber can get too hot and shears off much easier leading to rapid tyre wear this explains why dragster tire manufacturers use compounds that are far softer than other motorsports tires are only used for a quarter mile at a time and only in a straight line so it can be extremely soft for optimal grip and therefore acceleration if you're still watching please take a second to subscribe to the drive 61 channel dragsters complete burnouts to get the tyre up to temperature but also to lay a hot sticky layer of rubber down onto the track surface unsurprisingly the tyres are expensive they cost around 900 each and only last eight runs meaning they'll only cover a couple of miles before being replaced top fuel dragster engines produce up to 10 000 newton meters of torque about 10 times the power of the crazy 919 evo we spoke about in an earlier video all that torque means tires have to be clamped to the room to avoid the tyre simply being ripped off the wheel when accelerating top fuel dragsters since the early days have been rear-wheel drive and rear-engined this puts the majority of the weight over the rear axle giving it more grip they also have large and high rear wings to further increase the downward pressure at high speed in the first half second of a run the majority of the downforce doesn't come from the wings the draxes use the open exhaust headers as they are angled upwards and due to the speed and volume of the air being expelled push the car into the road they can produce as much as 500 kilograms of downforce enabling more grip for launch as the speed increases further through the run the rear wing begins to produce more and more downfalls up to about 3.5 tonnes of downforce at top speed which is about double what an f1 car produces the front wing is mainly used to stop the car from pulling a wheelie and rendering the steering useless this is also why draxes are so long the longer they are the more leverage the front wing has to counteract the torque from the rear wheels if the front wing has a larger lever effect the team can run the car with less wing angle and reduce drag while still keeping the front wheels planted there is a fine balance between the need for downforce and the drag it produces this balance is decided by the teams based on the conditions of the day a huge factor in the pace off the line is the clutch system draxers use an automated system for releasing the clutch in several stages the rate at which the power is deployed is pre-programmed by the teams based on the conditions at the moment of the run due to the changing nature of the strip teams hold off until seconds before the run to select the chosen clutch program small changes in the humidity or the track temperature can vary the grip massively if the grip is less the engineers select a program to release the clutch slower and reduce wheel spin the same goes in reverse if the track is grippier the teams can be more aggressive with the clutch system and put more power down into the track however the skill in a good launch is the timing one tenth of a second slower to release the brakes can mean massive time difference at the end of the run the car is launched using the brake which is a paddle behind the wheel the paddle holds the car still while the driver holds a specific throttle input when the lights go out the driver releases the brake pedal and masses the throttle so how do they make the engines produce so much power top fuel dragsters produce up to 11 000 horsepower and do this using nitro methane fuel it's used thanks to its ability to release more energy than regular race fuel it also doesn't require mixing with air to combust and it's extremely volatile it's normally mixed with about 10 methanol to stabilize the fuel and reduce the likelihood of engine explosions the dual magnetos are used to light the fuel which as mentioned earlier produce enough power to be used as arc welders this extremely powerful spark is needed to ensure the fuel is lit if it doesn't light unburnt fuel can build up and result in an explosion powerful enough to crack the engine block the engine is also supercharged and has a fuel pump powerful enough to supply 10 gallons of fuel about 50 liters every second thank you very much for watching if you enjoyed this you'll also enjoy these videos where i break down famous f1 drivers techniques or our other videos where i take a look at beautiful formula one engineering thanks and see you next time you

Channel: Driver61

Views: 9,334,987

Rating: 4.9228539 out of 5

Keywords: Dragsters, Racing, Motorsport, Tyre, Tyres, Top Fuel, Top Fuel Dragster, Engine, Drag Racing, Slow Motion, Slow Mo

Id: 8HsCB8gdV3c

Length: 9min 9sec (549 seconds)

Published: Sat Aug 01 2020