Hey all, went to a racing qualifying event last weekend and as always have things I wonder about, like:

- The 6 sec Top Methanol funny cars shifted three times going down the track, i.e. four speed transmissions which puzzled me. The commentator said they have three speed transmissions but I'm still wondering. Does anyone know what transmission these commonly use?

- In something I think was the Pro Mod class (they never announced the classes) a few times when they reversed back after the burnout, a crew member would run with it and spray something into the intake. Anyone know what this would be?

- How do the Top Fuel dragsters avoid flying down the track when doing the burnout? Do they actually have brakes on the front wheels? Or how do they do it?

Thanks :-)

1) i don't know for sure, but maybe the clutch fully locking up?
2) no idea
3)raw power- when they do an actual run, the clutch is set to slip a certain amount to prevent the tires form breaking loose. but, during a burnout, the clutch is fully locked up and every bit of horsepower is being put thru the tires, which just totally over powers them. the only thing keeping a Top Fuel dragster from hitting 400mph in the 1/4 mile is tire technology- which is kind of kept where it's at for the sake of the safety of the drivers and spectators. it would be fun if Goodyear would build a pair of "super tires" that could hook 7000hp to the tarmac and cut loose a TF dragster car on a rented track with no one else there to get hurt...

Top fuel dragsters do have brakes on the rear wheels they use to stop after a burnout, and also to stop after the parachutes scrub off much of the speed after a full run. Speeds are somewhat limited by NHRA mandating a maximum rear gear ratio (somewhere around 3.29 IIRC) and a mandated rpm limiter built into the ignition system.

- How do the Top Fuel dragsters avoid flying down the track when doing the burnout? Do they actually have brakes on the front wheels? Or how do they do it?

Thanks :-)

During the burnout, they are only running on one of the two magnetos so the power is down, and they only have half the fuel system turned on. The little brakes they run would have no chance against a full power engine. :D

They use methanol to spray in the intake after the burnout. Methanol evaporates quickly and may cause the intake linkage to develope frost, or freeze. The methanol spray avoids this.

During the burnout, they are only running on one of the two magnetos so the power is down, and they only have half the fuel system turned on. The little brakes they run would have no chance against a full power engine. :D

They also have a throttle stop. The butterfiles are barely open for the burnout.

Generally with AA/FD and AA/FC, if you watch the procedure carefully you'll notice that after each burnout the crew chief will reach somewhere near the throttle linkage and remove the throttle limiting pin (clip) and physically show it to the driver. Signifying that the driver then has full control of all of the engines power.

re burnout:

In addition to the other points made:
The burnout is started with tires wet, to help prevent them from "hooking up".