Driver relaxation, nitro launch, safety, and spark plug plating


Breathing routines are taught in yoga and relaxation training. They are recommended for a new driver who may be nervous in the early stages of getting licensed to drive a fast racer.

One breathing routine is to exhale for a longer time period than the time for inhaling. For example, inhale for a count of 4. Then exhale for a count of 6. I know from experience that an unbalanced inhale / exhale breathing ratio in this manner is relaxing. The ratio can be 2 / 3, 2 / 4. 3 / 4, 3 / 5, 4 / 5, 4 / 6, 4 / 7, etc. I was taught that any ratio and rate that keeps me oxygenated can be done. The ratio combination is less important. Maintaining an exhale time that is longer than an inhale time is what is important. I was taught to adjust the rate of breathing for my oxygen need. I was taught to breath at a rate that feels good, not too fast or too slow. I noticed that too do this, I had to conciously inhale faster and exhale shower. If my blood pressure was elevated from tension, it would be lower after a few minutes of controlled breathing ratio such as this.

Another trick that is taught is to block off one nostril, then exhale & inhale. Then change nostrils and exhale & inhale. Then change back and exhale & inhale. This method helps relaxation as well. Both of these breathing techniques are common in yoga and relaxation training. Controlled breathing methods such as these two are effective tools often used in the medical community for helping to relax a person in a stressful situation.

Pro Top Fuel Tune-up Info: launch engine speed with multi-stage clutch

In a drag racing Pro Top Fuel tune-up, a multi-stage clutch, the spark advance, and the fuel system are all adjusted to provide an engine flash to over 8,000 RPM on the hit out of the gate. Then the multi-stage clutch, spark advance, and fuel system are adjusted to pull the engine down to around 7,000 RPM in about 2 seconds. At that time and speed, the clutch is fully engaged. It remains engaged for the remainder of the run.

When the engine rotating assembly and clutch assembly are pulled down over 1,000 RPM in 2 seconds, deceleration of that rotating mass adds a couple hundred horsepower to the output of the engine. That extra horsepower is included with the horsepower coming from the engine. Both nitro amount and spark advance are regulated to limit horsepower during this time. Extra horsepower has to be reduced to compensate for this addition.

Nostalgia Top Fuel Tune-up Info: launch engine speed with single stage clutch

In a drag race Nostalgia Top Fuel tune-up, a single-stage clutch is used. Most rules organizations restrict the amount of fuel with a limitation in fuel pump size. As a result, most setups feed all of the fuel to the engine during the entire run. Only the spark advance and clutch settings are regulated for the launch. The engine flashes to a slip stall speed as the racecar launches forward. Clutch slippage holds that speed as the racecar speeds up. At a certain point, the racecar catches up to the engine speed. Then the clutch locks up. Often the engine is pulled down a bit as the clutch goes from slipping to lockup.

There are two schools of thought. One is a tight clutch. That setup keeps engine speed down, locking up early, and remaining locked up for the run. The second school of thought is to run a very loose clutch. That allows the engine to flash to a high engine speed on the hit. Then it remains at that higher value until the car speed catches up to the clutch speed. Slippage may continue into the higher engine speed as well if the clutch is really loose. That higher speed allows the fuel pump to send more fuel to the engine during the entire run. More power is made from the increased nitro volume. Unfortunately, clutch slippage is excessive. A lot of power is lost in clutch heat as well as excessive clutch disk wear. Several Nostalgia Top Fuel teams are secretive about their specific setup.


Unrealized danger
At a recent event, I watched a crewmember run up to a drag racecar to turn on a switch in the back of the car. The racecar was in pre-staged and was in the process of staging. I cringed as I saw the crew person reach right next to the parachute a moment before the racecar launched.

I recall an incident with a parachute. A crew person was standing close behind a racecar just before launch. The parachute accidentally deployed on the starting line and entangled the crew person. The racecar launched and dragged the crew person away.

I often see other crew persons and starting line personnel getting too close to the rear of a racecar with a parachute. Caution and awareness of this hazard is vital. New crew persons, photographers, and starting line personnel should all be made aware of the entanglement hazard from a parachute that may deploy by accident. They should all stay a safe distance away from the parachute, as the racer gets ready for the run.

Although it is often not thought of, most personnel on the starting line of a race vehicle assume that the racecar will launch in forward gear. There is often no consideration for the possibility of a malfunction or driver error causing the racecar to go into reverse. With the line-lock feature in many racing automatic transmissions, the line-lock is accomplished by putting the transmission in forward and reverse at the same time. That mode locks up the transmission. The launch is normally accomplished by releasing the reverse engagement mechanism. What if a failure occurred where the forward engagement mechanism released instead. In that case, the racecar would launch in reverse. Personnel around the rear of a racecar should keep a reasonable distance back in the event of a mishap such as this as well.

Spark plug plating

A twist to reading spark plug color
I contacted the manufacturers of spark plugs that we recently used. Those were NGK and Champion / Federal Mogul. I was researching the temperature of the spark plug body that changes the color of the plating. I was curious since we used spark plug plating discolor as a tuning indicator of engine heat. The customer service personnel from both companies said that information was not available. I was told that one of the common constituents in the plating compound is zinc, but plating compounds vary between the manufacturers. As a result, the temperature that would discolor the plating also varies between manufacturers. One customer service representative referred to the plating compounds as trivalent. That would indicate a more complicated reaction to temperature changes. Different plating compounds with different trivalent constituents would change color at different temperatures.

I was also cautioned that if the cylinder heads do not get to 150 deg. F or higher, the spark plug readings may not be reliable. Whew, that was a whopper of a curve ball to tuning! Unfortunately no further info is available at this time.

If spark plug color is a tuning indicator, staying with one spark plug manufacturer may be important. In addition, operating the engine around a repeatable level of engine heat may be even more important to value of any spark plug reading.

In our tuning, we often switched between different spark plug manufacturers. Our tune-up was in the middle of the operating window. I did not see a difference from the spark plug changes for the testing & competition that we did. Although one of our experienced crew members was already aware of & adamant about staying with one brand for more reliable color indications.

Both of the manufacturers that were contacted reported that their plating compound was proprietary. Therefore it is also possible that a manufacturer could change the metallurgical compound of the plating in their manufacturing process. The revised compound may discolor at a different temperature. Mixing old and new spark plugs should be avoided. This subject was only briefly covered in this report. It may be worthy of more study in your racing program if you count on spark plug color as a tuning indicator.