Please discuss here all your remarks and pose your questions about all racing series, except Formula One. Both technical and other questions about GP2, Touring cars, IRL, LMS, ...
strad wrote:They have revised the estimated horsepower from 8000 to 9500-10,000.
It is a little odd, the HP numbers have been climbing at about 500 HP per season over the last few years while almost nothing has change. The nitro % has been fixed for many years. The engine is very restricted by the rules. You can not introduce a new part without sanction body approval.
I think the HP numbers are BS fed to the viewing audience.
Brian
What part of my original statement implies that you had anything to do with the new HP number. You were just reporting the same kind of numbers I had also heard recently.
I use the term 'unknown' in-regard to the latest HP statement because I had heard the new inflated figures earlier this year. I would assume from one of the announcers.
So where in my statement did I remotely imply ANYTHING about you. I would be happy to learn if I made a mistake.
What are the chances that anything that broadcasters provide for the normal non-technical broadcast viewer is going to be any value to those posting on this form? It will be of as much value as the numbers posted above.... something on the order of +/- 2k HP if you are lucky. Of what value is that? If that is good enough for you, then you are in great shape.
flynfrog wrote:You accept the math from 10 years ago with 8000 hp figure correct? But not now that it is 10,000.
So you don't think the engine can manage to use 12% of the energy pumped to it?
I never said that 8k from 10 years ago was valid or that I accepted it, only that is 'what was said' then by unknown sources. Today the unknown sources claim 10K, but there has been no 'favorable' changes with the engine's performance. Completely logical to challenge the latest HP statements as being inconsistent.
Still not interested in doing the calculations myself.
I find your calculation worthless. A 12% efficiency gets you 10k hp. So then 24% is good for 20k hp! All sounds a little farcical and just more fodder for those claiming yearly HP gains.
Brian
I was simply showing that it is not an unrealistic number. It makes much more sense than trying to use aerodynamic numbers on a traction limited car in an acceleration race. Fuel flow rates are easy to measure and the energy density of the fuel is know.
Well, I have to thank you for the 'discussion'! Here is a paper that is almost directly on point. It defines some of the issues in determining a T/F dragster hp number.
NEW DESIGN OF A TOP-FUEL DRAGSTER REAR WING
citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.155.2434
Ok Brian..Let me explain.. I tell you that they showed the formula and how they arrived at that figure..not that they simply said it was that much,,,they showed it with formulas and numbers...What have you got? Oh yeah simply..."I don't believe you."
To achieve anything, you must be prepared to dabble on the boundary of disaster.”
Sir Stirling Moss
"Using measured torque and computer calculations, fuel-engine power is no longer a guess
For years, people have tossed around the figure of 6,000 as the amount of horsepower produced by supercharged, nitro-burning engines in Top Fuel dragsters and Funny Cars. And whenever that figure is mentioned, it is invariably followed by the caveat that it is an inexact number because no dynamometer can handle the output of such engines. So who needs a dynamometer? Using calculations and physical measurements, the overwhelming horsepower of fuel cars has finally been accurately determined to be a tick under 8,000.
Horsepower has been calculated using software and simple math formulas over the years, and, 10 years ago, 6,000 horsepower was an accurate figure. Racer Patrick Hale - mechanical engineer, president of Racing Systems Analysis, author of computer programs Quarter Jr. and Engine Jr., and consultant for race-car data analysis - has calculated horsepower in several National DRAGSTER articles in the past. In 1988 (one month before Eddie Hill ran the first four-second Top Fuel e.t.), Hale analyzed Hill's 5.066 record e.t. at the Gatornationals using the figures of car weight, tire rollout, wheelbase, and incremental times recorded by the track's clocks. Hale determined that Hill's engine produced 4,014 horsepower.
In late 1993, Hale used incremental times and other data from Cory McClenathan's 4.762 Top Fuel e.t. record, Pat Austin's 303.64-mph speed record, and Scott Kalitta's fastest-ever 308.64 in Topeka that fall to calculate the horsepower at 6,185. The e.t. decrease in those five years was a whopping three-tenths of a second. Speed, a reliable indicator of horsepower, jumped 22 mph, from 286 to 308. The increase in horsepower was 2,171.
Today, 10 years after McClenathan's 4.76 and Kalitta's 308-mph runs, the quickest e.t. has again decreased almost exactly three-tenths of a second and the fastest speed has increased 25 mph; 4.477 seconds and 333.91 mph are the best times ever turned by a piston-engine-powered car.
Hale crunched the numbers from Doug Kalitta's 4.486, 333.91-mph Houston run in April and determined the maximum horsepower to be 7,900, an increase of 1,715 over 10 years. Actual torque numbers that were recorded on Kalitta's hustling run and the calculated horsepower verify the accuracy of Hale's software-derived numbers.
Measuring for horsepower
Torque is measured; horsepower is calculated. Torque multiplied by rpm divided by 5,252 equals horsepower. The torque, or twisting motion, in this case is the output shaft that fits between the reverser and the pinion gear.
In addition to dynamometers, a transducer, or torque sensor in this application, can also measure torque. Torque sensors have been fitted to at least three fuel cars over the years: the Top Fuel dragsters owned by Connie Kalitta and Bill Miller and John Force's Funny Car.
Torque sensors are made of an almost impenetrable steel that can be designed in different shapes for different applications, but they all work the same way. Inside the torque sensor is a strain gauge with an output wire attached. A mechanical force applied to the torque sensor causes a subtle deflection of the strain gauge and a corresponding and linear change in the electrical resistance of the strain gauge."
Copyright National Hot Rod Association May 30, 2003
yep,,,I understand...
. The figures in you article is straight acceleration math and doesn't allow for the things that require additional HP to be calculated in.
Their straight math came up with 6500.. then they added the other things that had to be added into the calculation and came up with 9500, and the way they explained and showed it it seemed right.
BUT If you want to think it's only the 4 to 5000 I grew up with I dont give a rats ass.
To achieve anything, you must be prepared to dabble on the boundary of disaster.”
Sir Stirling Moss
"Using measured torque and computer calculations, fuel-engine power is no longer a guess
For years, people have tossed around the figure of 6,000 as the amount of horsepower produced by supercharged, nitro-burning engines in Top Fuel dragsters and Funny Cars. And whenever that figure is mentioned, it is invariably followed by the caveat that it is an inexact number because no dynamometer can handle the output of such engines. So who needs a dynamometer? Using calculations and physical measurements, the overwhelming horsepower of fuel cars has finally been accurately determined to be a tick under 8,000.
Horsepower has been calculated using software and simple math formulas over the years, and, 10 years ago, 6,000 horsepower was an accurate figure. Racer Patrick Hale - mechanical engineer, president of Racing Systems Analysis, author of computer programs Quarter Jr. and Engine Jr., and consultant for race-car data analysis - has calculated horsepower in several National DRAGSTER articles in the past. In 1988 (one month before Eddie Hill ran the first four-second Top Fuel e.t.), Hale analyzed Hill's 5.066 record e.t. at the Gatornationals using the figures of car weight, tire rollout, wheelbase, and incremental times recorded by the track's clocks. Hale determined that Hill's engine produced 4,014 horsepower.
In late 1993, Hale used incremental times and other data from Cory McClenathan's 4.762 Top Fuel e.t. record, Pat Austin's 303.64-mph speed record, and Scott Kalitta's fastest-ever 308.64 in Topeka that fall to calculate the horsepower at 6,185. The e.t. decrease in those five years was a whopping three-tenths of a second. Speed, a reliable indicator of horsepower, jumped 22 mph, from 286 to 308. The increase in horsepower was 2,171.
Today, 10 years after McClenathan's 4.76 and Kalitta's 308-mph runs, the quickest e.t. has again decreased almost exactly three-tenths of a second and the fastest speed has increased 25 mph; 4.477 seconds and 333.91 mph are the best times ever turned by a piston-engine-powered car.
Hale crunched the numbers from Doug Kalitta's 4.486, 333.91-mph Houston run in April and determined the maximum horsepower to be 7,900, an increase of 1,715 over 10 years. Actual torque numbers that were recorded on Kalitta's hustling run and the calculated horsepower verify the accuracy of Hale's software-derived numbers.
Measuring for horsepower
Torque is measured; horsepower is calculated. Torque multiplied by rpm divided by 5,252 equals horsepower. The torque, or twisting motion, in this case is the output shaft that fits between the reverser and the pinion gear.
In addition to dynamometers, a transducer, or torque sensor in this application, can also measure torque. Torque sensors have been fitted to at least three fuel cars over the years: the Top Fuel dragsters owned by Connie Kalitta and Bill Miller and John Force's Funny Car.
Torque sensors are made of an almost impenetrable steel that can be designed in different shapes for different applications, but they all work the same way. Inside the torque sensor is a strain gauge with an output wire attached. A mechanical force applied to the torque sensor causes a subtle deflection of the strain gauge and a corresponding and linear change in the electrical resistance of the strain gauge."
Copyright National Hot Rod Association May 30, 2003
Brian
From 2003? Feels like there should be more accurate calculations now.
What also feels strange is that the increase in hp was above 2k for a cut of .3 seconds 88-93, and then from 93-03 "only" 1.7k hp for a cut of the same .3 seconds even tho it had higher top speed. More speed->more drag->more hp required for a given increase of speed. Yes I understand tires and wings etc are better nowadays, but still.
hammarby88 wrote:Yes I understand tires and wings etc are better nowadays, but still.
No, the wings are not better performance wise. Until the last few years there was only one wing manufacture. The newest wing manufacture, Aerodine, had to produce a wing with equal performance to the old one before it was approved for use.
The tires have changed for various safety reasons, but they were never faster than the tire being replaced. The new tires were always introduce while some of the old tires were in use, so it was easy to judge the performance.
Tommy Cookers wrote:there's nothing difficult about making measurements as outlined in the 2003 article shown by Brian
this has been off-the-shelf equipment for the last 40 years and more
or the loads could easily be measured eg at the engine mount position etc
I had never considered the possibility of measuring torque through the drive shaft in a Fuel car. Well, this certainly takes some of the difficulty out of tuning for various track conditions. The crew chiefs should have accurate baselines, a 'book', for all the tuning variables. They should have an engine output model that predicts what a change of one of the variables will do. Some of the aura surrounding the T/F crew chiefs just evaporated for me.
Feels like there should be more accurate calculations now.