general top fuel ?

Here`s a ? for you more knowlegable guys, when a top fueler does its burnout and backs up to the line, the crew pics up the body on a funny car, then they all gather around under there, what are they doing? Then after they close it , and it pre stages one guy stays at the top of the engine and does something and the engine seems to smooth out a little then he goes to the back of the car and flips a switch or something on the wheelie bar, what are they doing? ive been going to races for years but i still dont know that much about it. and is it true that the sticky stuff they spray the track with will pull your shoes off if you walk on it in normal shoes? i heard some guy telling his buddy that last weekend, but i think its bs

removes the throttle stop from the injector more cable ..some guys use this to control the opening of the injector during the burn out
seats the clutch timmers,
check rpm from the timer box top.
loads the mag timmers ..
either put plugs in or out of the injector to adj the idle
turn on the computer ( racepak -proII data recorder ) from under the back of the car

anything else you need to know

stickey stuff is a como of vht traction compound ..will pull your shoes off trust me I have lost one on the starting line.

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Why does it look like they are only running on the back cylinders when they burnout, it looks like smoke only comes from the last two pipes

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Originally Posted by ch3no2fc

stickey stuff is a como of vht traction compound ..will pull your shoes off trust me I have lost one on the starting line.

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yep! i almost lost a shoe to!

that vht and slicks is amazing, we were fooling around on the track before the race one day and i had done a little burnout with my car with slicks on it. i thought i would just pull ahead and spin them some more. i thought i was going to twist the car in half when i torqued up the big caddy. there was no way i could get them to turn
slicks and vht-good
street tire and vht - might as well be snot!!!:LOL: :LOL: :LOL:

"i thought i would just pull ahead and spin them some more."

Not good. When you fire the tires up in the water, they get hot and resin comes to the surface, making the tire sticky. Then when you do a dry hop at the line, you tear off all the resin and you're left with a less-than-perfectly prepared tire. Watch any professional racer prepare to launch. No dry hop.

Original ? by HRDADDY....the driver also has a fuel lever to bring in the second pump. The burnout is done at a much leaner condition but has a tendency to load fuel slightly even then. The engines like to launch under as much fuel possible to set the car on it's tires and through clutch management it carries it out through the RPM band keeping it consistant for the run. Watch the rear pipes during a burnout, their rich and wet. But on the launch, they clean up and start burning evenly (hopefully throughout the run). Single mag is the only thing they run for the burnout for timing control and cylinder pressure control at that "unloaded" condition. The second mag is brought back in by pulling the ground wire off bringing it to life and it is also degreed sighty different for complete combustion therefore the second plug in each cylinder. I'd better stop here because I don't wanna be responsible for readers crashing their head on the keyboard from drifting off...lol.

Thanks nitro, that helps me understand better, you always hear the guys at the races telling there girlfriends different stuff like they know what there talking about, but half of it sounds like bs to me, hopefully one day i will have the money to drag race, and ill learn more

And hey talk/type all you want, this is real interesting to me, and im sure there are others who do not know this stuff

Thanks for your kind words. I can always tell when my mouth has run too long when I see my wife and my sons roll their eyes back in their heads. (Creeps me out). I never shut up when it comes to racing even when I don't know my brains from my butt.

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Originally Posted by techinspector1

"i thought i would just pull ahead and spin them some more."

Not good. When you fire the tires up in the water, they get hot and resin comes to the surface, making the tire sticky. Then when you do a dry hop at the line, you tear off all the resin and you're left with a less-than-perfectly prepared tire. Watch any professional racer prepare to launch. No dry hop.

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Thanks for explaining that. Seriously, with all due respect. :)

Nito... That's funny, my wife does the same thing. She usually follows with "when are you going to grow up??":LOL: I sometimes remind her I was doing this stuff before she was born and I still get a kick out of it..:LOL:

Some day we'll have to compare notes about the old days of FC and TF with the new stuff. It was really fun back then. :D

Yeah Bent! it was fun. As technology has grown, I find it more and more interesting. Many mentors of mine have opened my eyes through the years and I stand back all amazed at what they achieved and what it's worth to the effort we all try everyday to achieve ourselves. Who'd thunk 8,000 hp and still find a way to plant it to the ground. By the way, "Grow up?"....well....uh.....hhhmmmm.....I don't have the right answer for your wife or mine or anybody elses.............sorry, just ain't gonna happen....lol!!!

Since you pretty well covered what goes on under the hood here is an interesting bit of info:
On a slow 5.0 sec run say the motor averages 8000 rpm for the entire run...it makes only 667 revolutions, and since there are only 4 power strokes per revolution, it only makes a total of 2666 power strokes or 333 for each piston.

We've all seen a piston go up in smoke as it gets holed on a run. Ever try to burn a hole (melt a hole) in a piston with the average gas torch in the shop??. Think you can do it in 5 sec??? try it and see. Many are burned thru on a run at the 3 second mark. Gives you some insight to the heat produced in the cylinders.:eek:

When we were going down the road **) match racing we used to dump these things on each other like bad jokes. :LOL:

Hey bent, Good food for thought. One problem.....Math goes entirely out the window on a "Fuel" run. But I like what you are doing here. Now let's get down to reality. The Engine was warmed in the pits, Granted, it was only for a couple of minutes,trust me, they time them with a stop watch for record keeping and warmth on the engine so they don't over heat the clutch yadda, yadda, yadda. They'll "blip" it to check for response to linkage to rotating motion to ....Etc, etc. Now, "run" plugs go in. This doesn't sound like much but, remember, this thing has been together and running even though it has not been under load. Now don't forget this setup doesn't like "NOT" being under load. Warm it up before burnout to just the right head heat and burnout.....(no load again). Load this "Bad bo" up on launch and do the new math this thing does. The engine is "tuned" for optimum 7200 rpm. They desire this range because of hp and torque and fuel control. Meanwhile the clutches are now creating havocto bring the whole thing in motion. Various loading depending on the track and atmospheric conditions. Now, we all cross our fingers to hope the tires don't shake more than anticipated and then in all the gods of good fortune need to ride along to insure we have the blower belt "hang" on and frame and driver and what else can let go hang on. Now the math has changed. Look at a computer readout if you get lucky enough and you migh tjust bewilder yourself into a stuper and tell yourself.......I can't believe this thing works....LOL.....LOL. Not poking fun....just chuckling at the articles and "simple" math most people think a fuel motor goes through to make a run. These things make as much work as the biggest and baddest engines would do in a hundred lifetimes. And this takes place in minutes for the whole proceedure. Kinda cool huh?

....and the rest of the story.:LOL:
Actually I was only referring to the absolute power portion of a run and only in "about" numbers to make food for thought.

Computers and data loggers did not exist in my day and neither did excell spread sheets. You were your own data logger and sensors. The thicker your note book was the more stuff you could look at and therefore the better the guess was each run. Yes I really did have a 4 function calculator ($400 in '70) along with my engineering sliderule and graph paper. I did the math in the mo-tel room or while we were going down the road. And yes I did litter the road liberally with "out the window math" pages.

None of it was simple. None of it is today. If you want to run .001 3 straight runs everything better be perfect.

The only thing that is the same is the "Now, we all cross our fingers to hope the tires don't shake more than anticipated and then in all the gods of good fortune need to ride along to insure we have the blower belt "hang" on and frame and driver and what else can let go hang on. ":LOL:

And of course if you brought everthing home in one piece you didn't let it hang out far enough.