Dragsters Read this slowly and try to comprehend the amount of force produced in just under 4 seconds!
There are no rockets or airplanes built by any government in the world that can accelerate from a standing start as fast as a Top Fuel Dragster or Funny Car!
DEFINITION OF ACCELERATION
One top fuel dragster 500 cubic inch Hemi engine makes more horsepower than the first 4 rows of stock cars at the Daytona 500.
It takes just 15/100ths of a second for all 6,000+ horsepower of an NHRA Top Fuel dragster engine to reach the rear wheels.
Under full throttle, a dragster engine consumes 1-1/2 gallons of nitro methane per second; a fully loaded 747 consumes jet fuel at the same rate with 25% less energy being produced.
A stock Dodge Hemi V8 engine cannot produce enough power to drive the dragster's supercharger.
With 3,000 CFM of air being rammed in by the supercharger on overdrive, the fuel mixture is compressed into a near-solid form before ignition.
Cylinders run on the verge of hydraulic lock at full throttle.
At the stoichiometric (stoichiometry: methodology and technology by which quantities of reactants and products in chemical reactions are determined) 1.7:1 air/fuel mixture of nitro methane, the flame front temperature measures 7,050 deg F.
Nitro methane burns yellow... The spectacular white flame seen above the stacks at night is raw burning hydrogen, dissociated from atmospheric water vapor by the searing exhaust gases.
Dual magnetos supply 44 amps to each spark plug. This is the output of an arc welder in each cylinder.
Spark plug electrodes are totally consumed during a pass. After halfway, the engine is dieseling from compression, plus the glow of exhaust valves at 1,400 deg F. The engine can only be shut down by cutting the fuel flow.
If spark momentarily fails early in the run, unburned nitro builds up in the affected cylinders and then explodes with sufficient force to blow cylinder heads off the block in pieces or split the block in half.
In order to exceed 300 mph in 4. 5 seconds, dragsters must accelerate an average of over 4G's. In order to reach 200 mph (well before half-track), the launch acceleration approaches 8G's.
Dragsters reach over 300 miles per hour before you have completed reading this sentence.
Top fuel engines turn approximately 540 revolutions from light to light! Including the burnout, the engine must only survive 900 revolutions under load.
The redline is actually quite high at 9,500 rpm.
Assuming all the equipment is paid off, the crew worked for free, and for once NOTHING BLOWS UP, each run costs an estimate $1,000.00 per second.
The current top fuel dragster elapsed time record is 4.428 seconds for the quarter mile (11/12/06, Tony Schumacher, at Pomona , CA ). The top speed record is 336.15 mph as measured over the last 66' of the run (05/25/05 Tony Schumacher, at Hebron , OH ).
Putting all of this into perspective:
You are driving the average $140,000 Lingenfelter 'twin-turbo' powered Corvette Z06. Over a mile up the road, a top fuel dragster is staged and ready to launch down a quarter mile strip as you pass. You have the advantage of a flying start. You run the 'Vette hard up through the gears and blast across the starting line and pass the dragster at an honest 200 mph. The 'tree' goes green for both of you at that moment.
The dragster launches and starts after you. You keep your foot down hard, but you hear an incredibly brutal whine that sears your eardrums and within 3 seconds, the dragster catches and passes you. He beats you to the finish line, a quarter mile away from where you just passed him.
Think about it, from a standing start, the dragster had spotted you 200 mph and not only caught, but nearly blasted you off the road when he passed you within a mere 1,320 foot long race course.
...... and that my friend, is ACCELERATION!
There is a fine line between "Hobby" and "Madness"
Have been to many a drag meet, in Sydney, Ipswich and Perth...
Have mates that drag in many classes.... with pretty much home builds.
2 door LJ Torana with 2300hp... is one powerful rollerskate..... yes, that is what twin turbos the size of soccer balls does to a V8...
But.... Top Fuelers... are so far removed from the real world its not even funny!!!
Dragsters are another type of car altogether..... very much a lesser car.
I've been fortunate enough to be standing around when the engine builder for Lamatinna (a Melbourne chap, Theo.. look up Pavtek) decided how the Top Fueler should be built for the nights run.... based on air temp, air density, track grip (measured by walking on it and having his shoes sucked off his feet.... the track was that sticky)... most of the time they are tuning the car to take power out, not make more.
Then on first start after building, they run the engine on Alcohol... making a mere 3000Hp... shut it down once the tune has been set.... then fill it with Nitro!!! The next start, its making 6000Hp and everyone is wearing breathing apparatus and face masks..... yep, that shit burns ya eyes like nothing else...
Then its time to roll him out to the Christmas Tree.....
One big burn out... back up..... and i have heard drivers describe the launch the closest thing they have experienced to stomping their right foot on a landmine!!!
It is pretty much just a type of controlled explosion...
Thus... so far removed for anything anyone can buy, or drive.... its almost pointless.
Stand on it and steer!!!
Last edited by oceanboy; 18-08-12 at 08:48 PM.
I had read some where that a full dragster motor lasts approx 20 mins, have been curious to know if this is true?
There is a fine line between "Hobby" and "Madness"
20 minutes.... it Top Fueler, thats ancient... like anything... push it far enough...
A Top Fueler engine lasts about 10 seconds.... at full power.... you can add another perhaps 20 seconds in the pits at idle
The engine starts to detonate by half track..... spark plugs are gone....melted... history.
The massive burnout you see is done at no more than 1/4 throttle.... watch the butterflies
The total life expectancy of a Top Fuel engine is no more than 2 minutes!!!!
Thats if it doesn't hydraulic in the mean time.... Nitro burns slow, but expands dramatically, one misfire generally means the head blows off or the piston and conrod breaks... Blower belt breaking gives the same out come.. as does the Mag failing or a simple misfire.
Remember, to get a Nitro car down the track at record speeds, means HEAPS of fuel pressure, Nitro does not ignite easy.. but once lit.... its a whole lot safer... until a valve drops, then a back fire that destroys an entire engine!!!! in a heart beat .
They hand out or sell, Pistons with conrods after each run.... At the cost .... or risk of engine failure, why would they rebuild with used parts
Ironically, its actually one of the cheapest parts of the sport
Last edited by oceanboy; 18-08-12 at 10:55 PM.
Godzilla (18-08-12)
The fuel in a single cylinder.... yes, thats one single cylinder.... Gives you an idea what is needed to ignite that!!!
Let alone Fuel Pump pressure....
Pavtec, now theirs a familiar name from down the road, as is Bresiani, Rajab and Barry from Edge motorworks, and many others, all good engine builders.
Yes a top fuel lasts in seconds...everything is on the ragged edge, every run is ended with a tear down and rebuild in a tent on the track, amazing to watch them work, rebuilds done in less than an hour and ready to run again.
The biggest variable is the clutch, and how they get it to hook up, the RPM power band is only a few 100 rpm, the clutch is used to engage the drive instead of the rpm of the motor, hook up the clutch too fast and its smoke all the way with no traction, hook up too slowly and your loosing time.
9500rpm is not a big number today, our GTR did it daily however when talking 1000's of horsepower the harmonics and what it does to the steel is incredible, the steel literally is like plastic with the forces against it.
I still have my Bill Jenkins Chev drag engine building book from the early 80's, still today i read it (my bed time book), his pro stock Chev engines were turning 12000rpm in the 70's.......
In our case with our RB30 build we are grouting about 1/3 of the water jackets (read concreting) to strengthen the block to stop it splitting in half under the harmonics of less than 1000Hp, in the case of top fuelers the whole water jacket area is grouted for maximum strength, the run is too short to get it too hot so cooling is not a issue.
Dont know about the part where they only turn 500 revolutions light to light though, that does not sound right.
oceanboy (18-08-12),VroomVroom (19-08-12)
Thats is the funniest thing about any drag car.... the faster you get it to go down the track, the more money and time you spend for the engine to be on less
It all starts with a guy and his V8 that runs all day, then the more you modify it, the faster it gets and less its on for...
Until such point as it lasts 6 seconds
Last edited by oceanboy; 18-08-12 at 11:22 PM.
Thats what im trying to explain to my son all the time.
Do you build 1000Hp on the ragged edge, on the verge of self destruct thats life span is measured in how many 1/4 mile runs it lasts or do you build 800hp that will last a couple of years of 2 nights a week or do you build 600hp that can be daily driven for a few years or 400-500Hp that might see 100,000Km.
The harmonics that occur inside a engine as the power is cranked up is incredible.
Steel rods can only take so much HP but are reliable, the weight of them limits the RPM range, RPM can help build power, Aluminum rods can lift the RPM limit however due to their plastic soft nature and ease to soften and crack need to be changed regularly, talk Titanium rods and better have a good bank manager....
Those professional race engine builders have untold levels of understanding of whats going on inside a engine, many failures of engines are needed to understand whats right and whats wrong, studying wear patterns, cracks appearing, failures and improvements takes years of tear downs and research.
Its knowledge you cant be given, its all self taught the hard way.
Yep... spot on.... thats why i've always said Top Fuelers are almost not worth watching... from an engine builders perspective anyway.... As a spectacle, they are awesome!!
Then you look at common D@#g selling types that run Mr. Mad... a very old car now...
But in its day, used to turn heads... 1/4 mile wheel stands from a street car... hell yeah!!!
Now after you watched that... realise that car used to be outside the Pub on a Friday night... the owner used to drive it home, parachutes and all... hey, i never siad those Western Sydney boys were smart... but heck they were fun!!!
Last edited by oceanboy; 18-08-12 at 11:57 PM.
that is sick really sick.
Tagg
Godzilla (21-08-12)
Did i hear manual gear changes?
There is a fine line between "Hobby" and "Madness"
2000Hp.... Manual Gear box????Originally Posted by allover
Clutch pack???
Please explain!
There is a fine line between "Hobby" and "Madness"
The gear box wil be a strengthened 2 speed powerglide.
2 gears, Big Skid and Little Skid
V8 Supercars run about 800Hp and have a very special manual gear box.
You can pretty much forget a manual gearbox at high horsepower...
Godzilla would be the one to ask... i'm sure he has seen some 1000Hp + GTR's with a manual box.
allover, when these people build a drag car, its bottom up... everything from the wheels back to the crankshaft is built to hold and with stand the power their plan on building.
If you build a 2000Hp engine, you need a 2000Hp diff, drive shaft, auto, and so on....
Autos also allow a lot of other tweaks and settings.... and can handle a lot of power...
meshing gears at 2000Hp is not a good idea
If you want to watch a manual gear box drag car, the Pro Stock is awesome to watch.
Set engine size (5litre) and normally aspirated and 5 manual forward gears, all pushed into gear manually... and with in 100rpm of the optimal time...
Here is another angle.........
Last edited by oceanboy; 19-08-12 at 02:37 PM.
allover (19-08-12)
Drag racing transmissions.....so many variations.....auto with torque converter, manual clutches, transbrakes, manual bodies...list goes on
The guts of it.
The RPM power band on Drag engines tends to be quite high so the car needs to be launched at a relatively medium/ high RPM, as you know a family cars launch if you hold the car in drive with the brake pedal down is only around 1200-1400 rpm, drag racers are upwards of 5000Rpm.
The torque converter is what operates as the clutch in a auto, standard cars run large ones with large fans internally to transmit the fluid force while providing drive.
To increase the RPM on stage launch a smaller torque converter is used, this has smaller blades and can also have less blades allowing a greater amount of slip to the fluid, therefore providing a higher RPM when holding the brake to help produce a harder launch at the desired RPM.
Family car automatics are designed to shift gently, on race transmission the auto valve bodies where the fluid flows are modified, there are various levels of shift harshness from a crisper shift, right through to where you operate the shift lever like a manual and the gear changes are violent, transmitting a incredible amount of shock through the drive train, these are called full manual bodied automatics.
The 2 speed powerglide with full manual body is one of the most widely used automatic transmissions in drag racing, 1 gear change so minimal time lost but you need big torque to drive a car with only 2 speeds.
There are also transbrakes which hold the vehicles transmission in one spot while the driver just floors it without need to hold the brakes, release the transbrake and the car is launched.
Full manuals.....
GTR's have third gear issues when pushing big numbers, without a Dog box conversion and straight cut gears your pretty well screwed, we have no option but to go this way.
Clutch is then used for launch, gear changes dont need the clutch.
How to drive a dog box.....
V8 supercars use dog boxes, difference is they stay hard on the power when shifting and dont lift, their gear knobs have a micro switch inside which temporarily kill the engine power allowing the gear stick to be moved.
You can't think of the Hollinger in the V8's as having anything but a passing similarity with your average passenger car box, it's available in either h pattern or sequential shift, has to a recommended rebuild interval of every 1000 km's, and the last second hand one I saw for sale with a bell housing that would fit my engine was $20,000. You would have to need it badly at that price, the standard Tremec box in mine sells new at around $2500, (up to $4500 for some of the stronger versions) and they still have mostly helical cut gears.
Thats a sequential dog box and different again in the way it operates, there are normal H pattern dog box conversions for standard certain boxes with straight cut gears to take the strain off the case available, helical gears are quieter but strain the box casing limiting the total power that can go through them.
$20K is not a big number for a ready sequential box, most stock box straight cut gears conversion kits cost between $6K to $12K and thats only gears and shafts, you supply the working box and add the gears in yourself and its still a H pattern.
The manufacturer in the youtube link has many cars with high mileage running around without rebuilds, we know a few GTR owners that have done over 60,000Km without rebuilding the box.
Last edited by Godzilla; 19-08-12 at 06:59 PM.
Not far off though when you do the maths.
Redline: 9500RPM divide by 60 gives 158.33RPS (revolutions per second)
ET: 4.5 seconds
4.5 x 158.33= 712.48 revolutions. (thats the maximum revolutions the motor can turn in the time provided)
Considering that the Top fuel dragster would not be at redline for 100% of the run 500 to 600 revolutions from light to light would be a fair estimate.
Cheers,
Tiny
You can lead a person to knowledge,but you can't make them think
If you're not part of the solution, you're part of the problem.
Godzilla (21-08-12)
Ah that sounds logical now.
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