PREVENTING BLOWOVERS SUGGESTION #7
In response to a solution to dragster blowovers: How about something similar to what NASCAR uses when their cars start going backwards? They have that roof flap that pops up to keep them from going airborne. How about something similar on the wings, front and/or back that when the car reaches a specific incline, point of no return, it either shuts the car down or flips up and the air pushes the car back down.
Just a thought.
David Garcia
Las Cruces, NM
PREVENTING BLOWOVERS SUGGESTION #8
Good article. As with most safety concerns, the “powers that be” don’t seem to be real interested in working on safety unless it has affected some “high profile” team/driver.
Having said that, would taking a look at some NASCAR technology be appropriate? I don’t know much about the blowover, other that what I see in the “news”. Is part of the problem more than just the wheelstand, but the fact that the car gets so far up that air gets
trapped under the car and keeps the car going up? If so, how about body flaps? Some flaps, similar to the roof flaps in NASCAR, in the top of the body of the car that would let the trapped air under the body escape. This wouldn’t stop the wheelstands, but might stop the blowover. Would be a whole lot cheaper than some exotic devices, if it would work.
Also, a question about a comment in the article. You said “Ignition kill might sound simpler, but ignition will not kill a nitro motor at wide open throttle.” Not being directly involved with nitro racing, I have to question this statement. It seems to be in conflict with one of the rules in nitro racing. I believe that an “ignition rev limiter” is required in nitro racing, and that this device works similar to a rev limiter the rest of us racers know. It limits rpm by removing ignition from “random” cylinders.
My question is, how does this work on nitro cars if “ignition will not kill a nitro motor at wide open throttle”? I would think spark, or lack thereof, to the engine either does or doesn’t work. It isn’t selective.
Just an observation/question...
Thanks,
Bob Wold
Nostalgia C/Gas
PREVENTING BLOWOVERS SUGGESTION #9
Will, there are some really good solid-state electronics that are primarily an outgrowth of the DOD (Department of Defense) technology, especially guided missile control. Solid-state accelerometers and devices using the Coriolis effect or principle, or rate gyros are probably already on the market and easily adaptable to this. Not by me, as I am only an end user of the technology in the oil field.
In the oilfield, we saw quantum leaps in reliability and accuracy once this became available in the mid ‘90s. In fact, for several years the owners of these devices could not send them outside the U.S. because it was restricted technology, the government was worried China would get it.
I feel there already exists rate gyro technology that can take the acceleration of our race cars and determine the attitude of the car very accurately, because the DOD has done this forever for missiles. And some of these missiles pull huge (over 150) G’s at launch, especially the anti-missile missiles.
Blowover could just be the beginning, maybe even severe vertical and lateral acceleration without an attitude change (tire shake) could have a threshold installed so that a driver does not hurt himself -- just as a modern day fighter aircraft will not pull more than 9 G’s no matter how bad the pilot wants it to and the plane is very, very capable of doing.
Just a few thoughts. Yes, I am an engineer.
William D. (Dee) Kruse
TD/ET 4030
PREVENTING BLOWOVERS SUGGESTION #10
I kind of like the wheelie bar/brake deal. You could even take that one step farther and use that same wheelie bar as the “point of no return” switch to shut off the fuel. That could be as simple as a micro switch on the master cylinder linkage, although it would probably need to run through a timer also. One potential problem with the brakes in the wheelie bar deal, crew chiefs could start using it as a tuning device (if it gets back on the bar too hard it would squeeze the brakes, and probably respond quicker and more consistently than the driver yanking the lever).
To me the most obvious place to stop blowovers is at the front wing. The blowover issue is not just about the rear tires driving under the front end. As the speed increases and the front starts to lift, the angle of attack on the front wing is no longer causing down-force, it is lifting the front of the car up. Hold a ping-pong paddle out of the window of your car at freeway speed and see what effect angle of attack has! I think the front wing is the difference between a power stand and a blowover.
If you have a car with the front end three feet in the air at half track and instantly put 30 or 40 degrees of wing angle on the front end, I bet a paycheck that the front end will come down.
The aviation industry has lots of neat stuff for monitoring AOA. Stall vanes are like proximity switches attached to a little wing. G forces have no effect on them because the vane is “flying” along comparing the mounting surface (the car, wing, side panel, whatever) to straight line air flow.
I know the NHRA is real touchy about moveable airfoil surfaces, but if you could use the aviation industry’s indicators and actuators to maintain a preset AOA the front wing would always have down force, regardless of vehicle attitude.
I spent 25 years in the Air Force and aviation industry, but I am certainly not an expert in the airflow field. Find someone who is and see if they can help you with your “mission.”
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