NHRA Top Fuel

[RANDY P]

Originally posted by sammyg2
LOL, unfortunately top fuel flatbottoms went the way of the dinosaur. They are all retired or dead.
Nowadays they run top alcohol flats but no fuel flats that I know of.
They still run top fuel hydros but it aint the same, flatbottoms gotta be flown to go fast. Plus they have full capsules instead of parachutes packed on the back of their necks. Pansies

Oops, correct. I was referring to TFH - that's wild to watch..

rjp

[Jeff Higgins]

Originally posted by sammyg2
LOL, unfortunately top fuel flatbottoms went the way of the dinosaur. They are all retired or dead.
Nowadays they run top alcohol flats but no fuel flats that I know of.
They still run top fuel hydros but it aint the same, flatbottoms gotta be flown to go fast. Plus they have full capsules instead of parachutes packed on the back of their necks. Pansies

Jeff, you sure about that fuel shutoff in top fuel? I thought they had a lever in the cokpit to shut off the fuel. I don't know where i got that idea, maybe it's just something I assumed.

Pretty sure... I saw one get crossed up at about 100 feet and land on its side one time. With that big old slick on the ground, the car was rotating around it at idle speed. It finally ran out of fuel and died, and the driver got out. The TV announcer explained how helpless he was, with the lack of fuel or electrical shutoff where the driver can get to it. The announcer was Cruz Pedregon, before he got back in a car again. That was a couple of years back, so they may have changed by now. He did say it was for the drivers' safety, but it sure didn't look much "safer" for that poor guy.

[TheMentat]

Originally posted by Jeff Higgins
All pro class (top fuel, funny car, pro stock) elimination rounds are always on Sunday. You are right though, in that if you just want to see them run, Saturday is far better. Two rounds of pro qualifying means every car runs twice instead of the field getting halved in every round. Plus, they do run the first round of alcohol cars and lots of comp eliminator kind of stuff. There is much more going on on a Saturday.

Good to know Jeff... thanks.

[motion]

Here's an awesome slow motion vid:

http://www.youtube.com/watch?v=9O0b90G8Yhg

[kmhemi]

I love drag racing.

[Dixie]

A common medical issue amongst veteran top fuel drivers is detached retinas.

[RANDY P]

Originally posted by kmhemi
I love drag racing.

NHRA - THE WORLDS FASTEST MOTORSPORT

[sammyg2]

LOL, I ran drags for years, mostly eliminator stuff and boat digs, one day a friend of mine called it "motorized bowling".
I liked it.

[450knotOffice]

I've been to the NHRA Winter Nationals and the World Finals a few times, most recently this past year. In terms of the spectacle of the Top Fuel Dragsters and Funny cars, I've never experienced anything like it - ever. It has been described very well here so I won't try to rehash it too much but I will add that this year our seats in the stands were lined up dead even with the starting line, which are probably the best seats in the event. When those cars launch, the noise is literally instantaneous and you can actually feel it right through seemingly every fiber in your body. It literally makes your hair stand up, it's such an unnatural, immensely powerful sound. The instant those guys hit the throttle there seems to be ZERO lag from idle to max RPM. It seems nearly instantaneous. The wheels begin to rotate within the tires, which causes both cars to take a very quick "set" and squat together, and then they are just GONE!! The first few times you witness it you literally cannot come to terms with what you just saw. It seems almost impossible. I remember thinking last time I went that these guys have to be some of the bravest, most unflappable humans on the planet. I would never step foot into one of those monsters and drive one in anger. I am simply not brave enough for it. And the beating those guys must take!! Not only do they experience 5 to 8 G's during the run, they experience something like 5+ G's of deceleration when they pull the chute. This is how some of them get detached retinas.

[Jims5543]

At some point go stand at the finish line for a couple of runs. Its amazing.

[lm6y]

If you watch that video closely, the Hartley Racing rail has already dropped two cylinders just launching.

The first one I went to made me a believer. You don't breathe from the time they hit the loud pedal, until they kill it. I'm pretty sure it will change your heart rythm too.

It's wayy cool when you get two cocky drivers matched up (John Force is the king of this), and have a burnout contest.

[RANDY P]

The John Force tee shirt from several years ago:


"IT WILL NEVER END...."

I met him back in the early 90's at SIR - got a dead piston from his car off of him. Cool guy

rjp

[cegerer]

I had the opposite experience. I grew up on drag racing as a kid. Then me and a buddy went to a sports car race - a CanAm race at Elkhart Lake. We walked in and stood on the bridge over Thunder Valley. A few of the cars came rocketing under the bridge at probably 150-175MPH and then, without seeming to brake at all, just hung a right and flew up the main straight Holy friggin *****. Just like a giant slotcar track!

I still love drag racing but haven't been to a race in several years.

[kaisen]

More interesting engine specs:

The tremendous stroke of the 500 cu in Top Fuel motor creates astronomically high piston speeds. 8000 rpm at 4.5 inch (114.3mm) stroke yields average piston speeds in the 6000 feet per minute range (100fps)!

We all are in awe at the 19,000 rpm Formula One engines. But those engines have 1.56 inch (39.7mm) strokes! Average piston speeds are more like 4900 fpm (82 fps). The F1 motor would have to spin to 23,000 rpm to have equivalent piston speed.

Even then, think about how much a 4.19 inch (106.43mm) Top Fuel piston (and rod) weighs compared to a 3.86 inch (98mm) F1 piston. Think of the g forces involved!

To put it in perspective, a new 2007 997 Turbo generates HALF the piston speed (3008 fpm) at its 6000 rpm power peak.

BTW, one of the fastest piston speeds in a production car is the new Corvette Z06 with 4800 fpm and the 'old' F20C Honda S2000 motor with just over 5000 fpm.

E

[sammyg2]

The top fuel piston only has to last a few seconds, an F1 piston has to last for a few hours. A 997 turbo piston has to last for years.

[450knotOffice]

I'm guessing a Top Fuel piston of the correct dimensions to fit in a 997 TT would last until the end of recorded history.

[pwd72s]

Originally posted by sammyg2
A 997 turbo piston has to last for years.

Yup...until 12 miles or 15 minutes past warranty expiration.

[kaisen]

Originally posted by sammyg2
The top fuel piston only has to last a few seconds, an F1 piston has to last for a few hours. A 997 turbo piston has to last for years.

All very true.

The good ol' boys at NASCAR turn their 358 cu in pushrod V8s to 9300 rpm on the big ovals. With a 3.35 (85.1mm) inch stroke they create piston speeds around 5200 fpm, higher than that of F1.

And they crank them at 8000-9000 rpm for hours on end (ever sit and watch an entire NASCAR race? I can't say I've ever made it through one). They are designed to last a little over 800 miles

E

[Jeff Higgins]

While the rods and pistons are changed after every run, your typical rod or piston is actually good for 8-12 runs. They pull them and mark them, then put them in their "inspection" group to be x-rayed and magna fluxed back at the shop. The ones that pass are put back in the rotation. Every team has a maximum number of runs they will allow on any given component even if it continues to pass inspection. Interestingly, main bearings last a whole race day and cranks several race weekends.

The new forged blocks are actually strong enough to contain a rod or crankshaft failure. A rod can beat up a cylinder liner a bit, but they simply put a new one in and contnue to run the block. I remember the old Donovan 392 based, and the Keith Black 426 based cast aluminum blocks being all welded up after a season of multiple rod or crank failures punching holes through them. They got pretty ugly by the end of the season.

The amount of stress these things run under is indicated, or manifested, in some very unnexpected ways. Head bolt torque is one of them. Changing the sequence, or torque value, can have a +/- 500 hp impact on power output. Just by torquing the headbolts differently. The block and heads squirm around that much. You would think they would always torque for the maximum power output, but it has an effect on longevity as well. They are just now starting to really understand these things, and the gains they have made just in the last few years as a result have been amazing.

[kaisen]

Originally posted by Jeff Higgins
They are just now starting to really understand these things, and the gains they have made just in the last few years as a result have been amazing.

Top Fuel engines are at the bleeding edge of internal combustion (1000 hp per liter). As 'simple' as they appear on paper, it is almost a black art.

E