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Acceleration explained

RPM

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I know this has been posted before, but thought some of you might enjoy reading it again.


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 for, 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!​
 
How many of you have run at National Trail (Hebron)?

336.15 MPH at that track is absolutely insane. The Sarge likely had to have a cooler of ice water poured into his lap, to release the bite he had on the seat.

There is a county road that runs past the end of the track (and I mean on the other side of the fence). When the Pros ran, the police would close the road and they had a gate down there they would open up. The sand trap was on the other side of that road. The people that lived on that side of the road used to plant a garden in that area, every year. And it was not unusual for someone to go through the fence and end up in that garden.

The track is really pretty marginal for the quicker Comp cars, so it came as no surprise when the gods in Glendora moved that race to Norwalk.
 
I hope I did't miss it in the read.
A car that goes 300 in the quarter is probably going 250 at the eigth mile.
Yet, somewhere in my collection of little grey cells, I recall they toss aircraft off the front end of a carrier even faster than that.
 
I hope I did't miss it in the read.
A car that goes 300 in the quarter is probably going 250 at the eigth mile.
Yet, somewhere in my collection of little grey cells, I recall they toss aircraft off the front end of a carrier even faster than that.
I think you are right. A long long time ago. Garlits did some stuff with the Navy (if I remember right) and the jet fighter was faster than the dragster with the catapult, but the dragster was faster than the fighter by itself. That was about 35 years ago. So all that may have changed now.

I have a good friend that ran Top Fuel for awhile and it was amazing to look at those time slips and how fast the car was. They go from 0-100 mph in about 1 second. The hilight of this friends carrer in Top Fuel was he beat Bernstien in the first round. Bernstien qualified #1 and my friend #16..........Bernstien was not happy at all.
 
Bernstien qualified #1 and my friend #16..........Bernstien was not happy at all.

When I helped "Sneaky" Pete Robinson at a match race against "TV" Tommy Ivo and we beat him 3 out of 3, we did not make his Christmas card list that year!
 
This totally steam-driven system can rocket a 45,000-pound plane from 0 to 165 miles per hour in two seconds!

Quite a push. F/A-18 Super Hornet's carrier takeoff is computer controlled. The pilot has one hand on the throttles and the other is holding a grab bar on the side of the canopy frame. The deck officer won't signal for catapault shoot until he sees the pilot holding that grip. Those guys have to have a lot of trust in that computer.
 
This totally steam-driven system can rocket a 45,000-pound plane from 0 to 165 miles per hour in two seconds!

Quite a push. F/A-18 Super Hornet's carrier takeoff is computer controlled. The pilot has one hand on the throttles and the other is holding a grab bar on the side of the canopy frame. The deck officer won't signal for catapault shoot until he sees the pilot holding that grip. Those guys have to have a lot of trust in that computer.


That has got to be a lot of G's.
 
There's one thing in there I disagree with

"Top fuel engines turn approximately 540 revolutions from light to light! Including the burnout, the engine must only survive 900 revolutions under load."

That might be true if it was under full load from start to finish. But with todays slipper clutches and staggered pneumatic switches and all, you will get massive slipping until full engagement at 3/4 track or so.

I'm I right?
 
An aircraft carrier launch is about 3.75 G's. All of that happens in about 250 feet. Carriers are huge ships but when you stand on the deck and realize what happens there, you quickly conclude that it's a very short runway. Scarey short. Way too short for any sane person to ever want to use for any airplane; let alone a big jet. Believe me, F18's are not small jets. I see them every day at work.
 
I would think there is a fair amount of load over the whole run, not just at total lock-up.



Depending on how they have the timers and clutch fingers set to lockup, you will get a large amount of slippage at the the start and progressively get closer to lockup the further down the track you go until full lockup around 3/4 track or so. With the amount of HP they are putting out, if they had lockup at the start it would just immediately go up in smoke. I betcha at the start you are getting atleast 50% slippage off the line which would blow the 540 rpms out the window.
 
Someone has been playing with a calculator to determine that number. They're figuring something around an average of 7,500 RPM for 4.5 seconds or something to that effect. Cannon positioning and counterweight are going to play a part in how much the discs are slipping at any given point on the track.
 
Yes, I remember both. I remember being at a race and Fuzzy was amazed we were running a McKinney car in Comp Eliminator. He was familiar with the big cars McKinney built, from the years he had worked for Eddie and Ercie Hill. Fuzzy and Jana were good, hard-working people. It's hard to believe he's been gone 10 years.

Actually, I think a buddy of mine worked for Mullins for a brief period. He had worked for Bill Barney, Walt Austin and Brad Anderson, before retiring somewhere in the Oak Ridge area. He was living on a houseboat down that way, somewhere. He came out of the woodwork and spent some time with Mike Thomas' Pro Stock team and then I think he spent a few races with Mullins. After that, I lost all track of him. If you ever hear the name Mike Cooper getting tossed around in those circles, see if you can sort what he's up to, these days. Coop used to come back to town every year to visit his mother at Christmas, but she must have passed as I haven't seen him in 4-5 years.
 
Small world time...well, kinda. A buddy (David Scheelk) and I used to make and sell a clutch grinder for the alcohol racers primarily and our first customer for one was Mike Cooper when he was helping John Constanza along with Mike Troxel. David probably knew Mike Cooper from his (David) being crew chief for Randy Smith after he bought Bill Barneys Castrol dragster. David later tuned Tate Branch to several division 4 Alcohol Funny Car crowns as well as building a new car for him here in my shop.

You might have seen a few of the grinders around. They went by the name Pro-Surf. Of course this goes back to 1997 when we started building them.

Just before I started to type this, David called and I asked him if he had heard anything of Mike Cooper recently and he hadn't.

Pro-SurfClutchGrinder.jpg
 
George, you're absolutely right. It is a small world. Yes, I've seen several of those grinders in use. I was never aware of who made them, however.

We always used a Ray Franks grinder, which was actually more of a cutter than it was a grinder.

profiler.jpg


I remember at one point, Jenkins was trying to convince us it was time for a new car, to run A/D. He wanted us to run his 500" Pro Stock stuff, because he said we were about the only ones he knew that understood the clutch had to be serviced after every pass and we weren't afraid of the work it took to do it. And back then, he was right. Other teams would come back and service valve springs and make clutch adjustments or convertor swaps. At the time, we rarely ever had the valve covers off (you didn't need to change springs when you ran good ones, right Ron? :winkn:), but the clutch came out of the car after every run. If I saw anything unusual on the computer graphs, we might cool the clutch so we could measure for wear, but then it came out. Pop off the body panels, pull the pedal linkage off the bellcrank, loosen the motor mount clamps and slide everything ahead. Then we would take the bellhousing trans and all, in one, fell swoop. I watch people pull the trans and then the can and wonder why they're wasting their time, instead of yanking it all at once. Toss the lanyard around the stands to preserve heights, yank off the hat and one disc would go into the cutter. We would sand the floater, cut the other disc and throw it back together. Set heights for the new disc thicknesses, toss the can and trans back in and slide it all back and tie it down. I would hook up the linkage as Brian was getting in the car so I could set air gap and then we were done. There were times I didn't think was ever going to be able to scrub all the clutch dust out of my pores and from under my fingernails. :no:

If we were at a national event, I could always rely on either Jenkins or Lanny Miglizzi to provide me track information, so I would know what I needed to do with counterweight on the clutch. I first met Lanny and his dad, Tony (R.I.P., my friend), when we ran their clutches (L & T Clutches) back in the late 80's and early 90's. Tony is absolutely fanatical when it comes to track conditions. I've seen him show up at tracks on tech days and then take his cameras out and crawl down both lanes of the track. He would then map out every single high spot and low spot in each lane.

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In this 2nd video, you'll see Lanny come into the screen at about 5 seconds and he certainly didn't care for the way the starting line crew were cleaning the track!

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