Top Fuel 7000 BHP, how....
Top Fuel 7000 BHP, how....
Author
Discussion

Tony 1234

Original Poster:

3,465 posts

242 months

Monday 13th August 2007
quotequote all
do they know this?, it's not as if they can be taken down to the local Rolling Road.

Do they work the bhp out by how much Nitro is put in???? and how do they know what bhp it's making before adding any nitro???? because i'm sure R/Rs only go to 1200bhp?

Sorry, but at my age these things matter

Thanks

Vixpy1

42,687 posts

279 months

Monday 13th August 2007
quotequote all
I would suspect they put them on engine dynos

Tony 1234

Original Poster:

3,465 posts

242 months

Monday 13th August 2007
quotequote all
Vixpy1 said:
I would suspect they put them on engine dynos
I would have thought the same applied, do engine dyno's go to 7000bhp ?

Vixpy1

42,687 posts

279 months

Monday 13th August 2007
quotequote all
Tony 1234 said:
Vixpy1 said:
I would suspect they put them on engine dynos
I would have thought the same applied, do engine dyno's go to 7000bhp ?
I actually don't know hehe


BennettRacing

729 posts

226 months

Monday 13th August 2007
quotequote all
No as far as I knw nothing is able to measure correctly, if I had to guess I would say its worked out by weight and the ET's and mph's that they run.......

Ie 4.42 at 337mph in a 2225 pound car would need......


NitroMouse

11 posts

218 months

Monday 13th August 2007
quotequote all
Tony,
It sounds like your confusing "nitro" (ie: nitromethane - the fuel used in top fuel dragsters and funny cars) with "nitrous" (ie: nitrous oxide - used as to promote oxidising of another fuel). This is something which is often the case with the Max Power brigade who even at "media" level seem to not know the difference, hence the confusion has entered the mainstream. As such you don't "add" nitro to an already running engine in your terms. Nitro is the fuel, and ok its not that simple because there is the Methanol percentage to consider, but thats just complicating matters.

Unlike some little boys with a Corsa we are not talking about their supposed "180bhp motor" that they've added up in their head from all the bits they've stuck on, with a "75 shot" of nitrous oxide, purely based on how big the jets might possibly be, if they've got what they think they might have.

Although I believe that some fuel teams in the US now have a "dyno" capability in-house (DSR and Doug Herbert being among them), most of the figures quoted come from extrapolating the forces which are applied in order to perform the acceleration which we can measure. The Kalitta team in the US have also used load sensors (S.W.I.F.T. or Spinning Wheel Integrated Force Transducers) on the car in testing to measure the torque applied (which is all a dyno does), which showed that under heavy load at around the point of clutch lock-up the motor was making in the region of 10,000 horsepower.


Edited by NitroMouse on Monday 13th August 15:50

dragsterworld

42 posts

226 months

Monday 13th August 2007
quotequote all
This article gives some explanation of how horsepower can be caluclated for Top Fuel dragsters...

http://findarticles.com/p/articles/mi_qa4078/is_20...

cougarracing

206 posts

218 months

Monday 13th August 2007
quotequote all
you couldnt dyno 7000hp. i remember reading an article while studying my engineering degree. apparently someone in the states recogned be could build a dyno for jet engines. the us government subsidised him and as a prototype he used a keith black motor which showed around the 2500hp mark then shook the dyno to bits....

nitromaniac

407 posts

224 months

Monday 13th August 2007
quotequote all
This is from Al Booton, one of my American drag racing friends.
One of the cam companies (Crane I think) used to make a wheel type calculator that you could estimate the horsepower. Now l think there is computer software to do that.
There are some dyno's that can take a blown alcohol motor, because the guy l used to crew for had his engine on it. He came to the conclusion that he did not need to know the horsepower, it was just wearing out his big money parts.
l was over there a few weeks ago, when he was throwing out a $1,000 set of rods because the transmission had broken and instead of the 9,400 he shifts at, the engine had hit almost 10,000 and he was not using those rods again.
Jay Payne (Brad Anderson's son in law) shifts at over 10,000, but then he has Brad to get him more parts.
These are 526 cubic inch engines.


P15TON

495 posts

251 months

Monday 13th August 2007
quotequote all
Torque arms (mounted to chassis from drivetrain with load cell attached) have been used by some NHRA teams for some time. Power available from blown Nitro engines is almost limitless. I believe 9840bhp & 8000+ lbs ft of torque were the figures given to me from one of the crew chiefs that was helping us with our T/F car.

Tony 1234

Original Poster:

3,465 posts

242 months

Monday 13th August 2007
quotequote all
dragsterworld said:
This article gives some explanation of how horsepower can be caluclated for Top Fuel dragsters...

http://findarticles.com/p/articles/mi_qa4078/is_20...
Thank you young man

NitroMouse

11 posts

218 months

Monday 13th August 2007
quotequote all
P15TON said:
Torque arms (mounted to chassis from drivetrain with load cell attached) have been used by some NHRA teams for some time. Power available from blown Nitro engines is almost limitless. I believe 9840bhp & 8000+ lbs ft of torque were the figures given to me from one of the crew chiefs that was helping us with our T/F car.
Which would indicate that the peak power shown would be being made at around 6400-6500 rpm, somewhat under the 7500 - 8000 rpm usually quoted as the operating range of a fuel motor, and suggests that as I said before the peak output is reached as the clutch locks up and drags the motor down. Am I thinking along the right lines Peter?

Edited by NitroMouse on Monday 13th August 18:15

P15TON

495 posts

251 months

Monday 13th August 2007
quotequote all
From memory (it's a couple of years now, and I've been to bed since then) our motor used to go straight to 6000 at the hit, and make a nice straight pull up to a max of 7500. Some guys used to run to 8000, but it depends on the tune up.
When asked 'how much power' the best answer is 'as much as we like!'

KP1

139 posts

225 months

Monday 13th August 2007
quotequote all
This onboard dyno are cool!
http://www.land-and-sea.com/rotary-shaft-dyno/rota...
I remeber a article in National Dragster magazine when they tried this one on Bill Millers Top Fuel dragster and got very close to 10000 horsepower.
Blown promod cars shift close to 10 grand and get 15 to 25 runs on the rods depend on which brand they use.

AM

1,705 posts

226 months

Monday 13th August 2007
quotequote all
Vixpy, out of curiosity, what's the highest BHP you've measured on your rolling road, and what was it, etc ?

Vixpy1

42,687 posts

279 months

Tuesday 14th August 2007
quotequote all
AM said:
Vixpy, out of curiosity, what's the highest BHP you've measured on your rolling road, and what was it, etc ?
580 at the rear wheels (Capri.. yes, really!)
580 at the wheels (4wd, Lancer EVO)
500 at the front wheels (civic type R)

As for then most powerful car at the crank, i would say a drag subaru with a drag auto box, the wheels figs where lower due to massive losses in the auto box, but i would say it was probably producing almost 800bhp on the dyno, without Nitrous.

KP1

139 posts

225 months

Tuesday 14th August 2007
quotequote all
How many G:s needs it to go 280 mph in 3.0 seconds at the 1/8 mile like the fastest runs in US ?

Eurodragster.com

657 posts

222 months

Tuesday 14th August 2007
quotequote all
I have a spreadsheet which calculates G-forces given the incrementals. It's not very reliable for the first 60 feet (because when the clocks start the car is not doing 0 mph, and I don't know how many mph it is doing) but it gets more accurate from there on in. Here is what it says when you feed it Brandon Bernstein's 3.109/273.88 mph at half track and 4.556/328.30 at the quarter during last weekend's qualifying at Brainerd:

0-60 feet: 5.05 G
60-330 feet: 3.03 G
330-660 feet: 4.49 G
660-990 feet: 1.94 G
990 feet-1320 feet: 1.46 G


KP1

139 posts

225 months

Wednesday 15th August 2007
quotequote all
I have seen comments from TF drivers that the car makes more like 7-8 G:s when the clutch starts to lock up, I assume they takes that from the data recording. I don´t know what the best is at 1/8 since they don´t have records for that but I have seen over 280 in 3.00 seconds, pretty fast!

Eurodragster.com

657 posts

222 months

Wednesday 15th August 2007
quotequote all
With the exception of the 0-60 feet number the figures will peak higher than the spreadsheet displays because those are averages over a hundred metres or so (because that's all the incrementals give you). Even so, you can tell exactly where the clutch is kicking in and you can plainly see the acceleration curve drop after half track smile

The only comparison I have ever done between my spreadsheet and an actual run was a pass by Dave Wilson's Top Methanol Dragster and my sheet was showing the acceleration over 0-60 feet as 1 G too high for reasons I explained in my previous posting.