Top Fuel Pics

[hardingfv32]

I heard 10K the first time this season. The cars are not much faster this year. Nothing new technically. I know NHRA is not going to allow ANYTHING that increases performance. They have been increasing the penalties for blowing up (oil downs) so the teams are getting less aggressive with their race setups. It does not add up.

It rubbed me wrong when I heard the 10k HP statement on TV, so that is why I challenge the statement. So unless you can present some reason for the increase in HP, I will contend it just BS for ignorant fans. Since this is a technical forum I though a more accurate view of the HP numbers was required.

I'd be happy to learn about something new in the Fuel class engines.

I have followed Fuel cars from S Calif. sense the beginning in the 60's. Still go to the Pomona yearly on qualifying days when I can visit with crew members.

Brian

[flynfrog]

prove they dont.

[strad]

You're not listening...they guesstimated 8000 then they got to thinking about how fast they accelerate and broke out math and the necessary formulas and low and behold their guesstimate was wrong...it's always been a guess because there ain't no dyno that you can lash them to, and the math works out to between 9500 and 10,000 horsepower.
Jeeeeeeeeeeeeeeeeeeez

[hardingfv32]

"Measuring the power output of a top fuel engine directly is not feasible. This is not, as is sometimes stated, because no dynamometer exists that can measure the output of a Top Fuel engine; in reality, dynamometers capable of measuring tens of thousands of horsepower at the appropriate shaft speeds are in widespread use. Rather, it is because a Top Fuel engine cannot be run at its maximum power output for more than about 10 seconds at a time without overheating (or perhaps exploding) as would be necessary to take a reliable power reading. Instead, the power output of the engine is usually calculated based upon the car's weight and its performance. The calculated Power output of these engines is most likely somewhere between 7000 and 8500 horsepower (approximately 4500-6000 kilowatts), with a torque output of 8135 N·m (ca. 6000 lbf·ft) and a brake mean effective pressure of 80–100 bar (0.8–1.0 MPa)."

So no one attempted to do the math before? The math has not changed for the last couple hundred years. They could do the math 5 years ago and got 7-8k hp. Today the do the math and get 10k hp. Neither the math or the cars/engines have change in those five years, so why the move from 8k to 10k. It is caused by the desire to feed more spectacular BS to the fans.

Brian

[flynfrog]

well lets see your assumptions and your figures. Are you taking into account that the car is traction limited for pretty much the entire run?

[hardingfv32]

Calculations are not required to prove the logic of my statements.

I would have to research how to make the calculations. I am not interested. I will help you with the variables or assumptions if you want to get the formulas started. I read an article on a new T/F wing design a few weeks ago. I believe they mentioned their target design figures which were developed at 300 MPH. The main point of the article was to demonstrate the trouble they went through to get the new wings approved by NHRA. They had to prove that the new wings did not add any performance over the current units (there was only one supplier at the time).

I would say your goal was the power required to run at 300 mph. There is also the issue of what type of HP number you are talking about. They say the blower requires a 1k hp at max rpm.

Brian

[strad]

Brian, Whatever You are absolutely right. In fact nobody knows nuthin except you..

[flynfrog]

so you accept other people math when it suits your argument reject it when it does not? Great logic! I don't think that using the acceleration of the car is a good method. The acceleration is more tires and clutch based in these cars.

Based off fuel flow
Nitro is 5000 BTU / Lbs
Nitro weighs 9.39 LBS / Gallon
The car burns 1.5 Gallons / sec
Assume 90% nitro mix ignoring energy from the rest of the mix
1 BTU/s = 1.414 hp

5000*9.39*1.5*.9*1.414 =89622.86

89622.86*.12=10754.74

To reach 10000Hp the engine would need to be less than 12% efficient.

I do open my math to peer review I did it real quick over lunch.

[Pierce89]

I heard 10K the first time this season. The cars are not much faster this year. Nothing new technically. I know NHRA is not going to allow ANYTHING that increases performance. They have been increasing the penalties for blowing up (oil downs) so the teams are getting less aggressive with their race setups. It does not add up.

It rubbed me wrong when I heard the 10k HP statement on TV, so that is why I challenge the statement. So unless you can present some reason for the increase in HP, I will contend it just BS for ignorant fans. Since this is a technical forum I though a more accurate view of the HP numbers was required.

I'd be happy to learn about something new in the Fuel class engines.

I have followed Fuel cars from S Calif. sense the beginning in the 60's. Still go to the Pomona yearly on qualifying days when I can visit with crew members.

Brian

I heard an announcer mention 11K HP a couple years back. I'm not claiming it was true or that they could use 11K HP. Its just what I heard

[Pierce89]

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. The sanction body has absolutely no interest in increases of performance.

I think the HP numbers are BS fed to the viewing audience.

Brian

Well I wish I had recorded the Northwest Nationals for you. They have been saying 8000HP for ages Brian and so they worked it out mathematically and showed the formula.
Ya know, all you ever wanna do is argue and try to pick stuff apart.
Have you ever been involved in drag racing?

@Brian. Your way of questioning often has tone to it, SEEMING like, "You're full of sh!t". Thats why people often respond negatively to your questioning. I realize you're just trying to "further your understanding" , but other people seem to feel challenged or insulted. I'm just trying to help here. I'm for or against no one. Just describing what I see.

[hardingfv32]

so you accept other people math when it suits your argument reject it when it does not? Great logic! I don't think that using the acceleration of the car is a good method. The acceleration is more tires and clutch based in these cars.

I don't recall accepting anyones math. I said I would help you with yours. I would say it is better to figure how much power is required when the car is 'at' 300 MPH as we can get data on wing drag, frontal area, etc. If using fuel consumption you are missing some important information.

"As nitro burns there is extra oxygen created, meaning a lean condition. So to counteract this more nitro is injected, vicious circle that ends up with the fuel still burning as it leaves the exhaust headers. This is why you can see flames clearly." Statement not verified.

"The high heat of vaporization of 0.56 MJ/kg together with the high fuel flow provides significant cooling of the incoming charge (about twice that of methanol), resulting in reasonably low temperatures." Inter-coolers not allowed.

"Very rich mixtures are necessary to reduce the temperature of combustion chamber hot parts in order to control pre-ignition and subsequent detonation."

"the nitro in some cases adds up to 30% volume to the oil sump during a single run, due to wash-down." Maybe an 18 qt oil system. The oil is replaced after each run. That would be about a gal of fuel in the oil.

You add up all the unknowns, for us, I would say calculating HP from fuel consumed is not valid.

[flynfrog]

so you accept other people math when it suits your argument reject it when it does not? Great logic! I don't think that using the acceleration of the car is a good method. The acceleration is more tires and clutch based in these cars.

I don't recall accepting anyones math. I said I would help you with yours. I would say it is better to figure how much power is required when the car is 'at' 300 MPH as we can get data on wing drag, frontal area, etc. If using fuel consumption you are missing some important information.

"As nitro burns there is extra oxygen created, meaning a lean condition. So to counteract this more nitro is injected, vicious circle that ends up with the fuel still burning as it leaves the exhaust headers. This is why you can see flames clearly." Statement not verified.

"The high heat of vaporization of 0.56 MJ/kg together with the high fuel flow provides significant cooling of the incoming charge (about twice that of methanol), resulting in reasonably low temperatures." Inter-coolers not allowed.

"Very rich mixtures are necessary to reduce the temperature of combustion chamber hot parts in order to control pre-ignition and subsequent detonation."

"the nitro in some cases adds up to 30% volume to the oil sump during a single run, due to wash-down." Maybe an 18 qt oil system. The oil is replaced after each run. That would be about a gal of fuel in the oil.

You add up all the unknowns, for us, I would say calculating HP from fuel consumed is not valid.

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?


Accelerating to 300MPH in less then 3 seconds takes much more power than it would to maintain 300mph. As stated earlier these cars are traction limited not power limited.

negating drag it takes 4 230HP to accelerate the mass of a top fuel dragster to speed in 3 seconds. This would assume perfect traction no drive train losses ect. I do not have the CD of top fuel car but it wouldn't be of much use as the car is not drag limited.

Im done doing your homework for you. If you cant do the work on your own you have not basis to make your claims and I think we are done here.

[strad]

I think we are done here.

[-o<

[hardingfv32]

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

[strad]

unknown sources claim 10K]

Just because I didn't record it doesn't make it unknown and now you're questioning my honesty.
It was worked out mathematically during the broadcast of the the Northwest Nationals last weekend.
Find a copy of that broadcast and quit calling everyone that disagrees with you a liar.
The math formulas are available...go work it out to disprove it or shut up.