Nitrous has been used in our industry for more than 30 years now. During that time, there have been plenty of magazine articles on how to use it, types of kits available, new products, dyno test results, etc.
But the one thing that hasn�t been discussed as often is nitrous safety. So, here are some tips on the safety issues involving nitrous oxide.
Let�s start with the �aluminum� nitrous bottle included in most of the kits you see on the market today. There are several sizes and capacity aluminum bottles available. Bottles are rated by how much nitrous they hold in terms of weight�generally in sizes ranging from 10-ounce to 50-pound-capacity bottles.
The most common capacity (sometimes referred to as �size�) bottle is 10 pounds. So let�s start here.
On the label you see on the face of the nitrous bottle is the �TARE� weight, which designates the empty weight of the bottle and valve without the nitrous oxide. The weight of a bottle valve assembly can also vary up to an extra pound, depending on the manufacturer.
You will also see that the label will show the total weight of the bottle when full (filled to rated capacity). This is very important, in that overfilling a bottle, although possible, can have extremely bad consequences. A bottle is designed to be filled to 68 percent of its capacity and must have an �air bubble� of 32 percent to allow for expansion of the nitrous when it gets warm.
Speaking of temperature, when nitrous is discharging out of the bottle, it will be at minus-127 degrees and will freeze-burn you almost immediately! Care should be taken to wear gloves and goggles whenever filling a nitrous bottle.
Never put an open flame on the bottle to bring up the pressure. Doing so will begin to �anneal� the aluminum bottle, altering the microstructure of the material and causing changes in properties such as strength, hardness and ductility. If the integrity of the bottle is compromised by using an open flame, it is very possible to blow-up the bottle.
Mike Thermos of Nitrous Supply, Huntington Beach, Calif., can be reached at (714) 373-1986.
I�m having trouble deciphering what the punched out holes mean on my NHRA chassis tag. The car that I purchased is a 1969 Nova that has a roll cage like you see in the NHRA Rulebook and it also has a funny car cage installed. The blue/silver NHRA chassis tag is punched out 8.50 & Slower and at the bottom N/A. Along the left side punched out 09 and along the top 7. What does it all mean?
Chassis Tag Chuck
Chassis Tag Chuck,
The punched out dates along the left side and the top show that your car passed NHRA Chassis inspection in the 7 th month (July) of 2009 and would expire in three years on July 31, 2012. The punch out of 8.50 & Slower and the N/A shows that it meets the NHRA full-bodied spec that you see in the NHRA Rulebook. The funny car cage by it self does not let your car run under 8.50 in the 1/4-mile. The SFI 25.4 or 25.5 spec for E.T. of 8.49 down to 7.50 does require a funny car cage and numerous other chassis items before you can upgrade to either of those SFI specs.
At last Friday�s test & tune my Super Street Turbocharged Mustang ran 10.20 at 140 mph and I was not allowed to make any more runs unless I ran 135 mph or slower. I thought if I ran 10.00 or slower in the 1/4-mile then mph was not a factor?
In the 2011 NHRA Rulebook in Section 7 Super Street, page 1, Designation, third paragraph, it states �Any vehicle running faster than 135 mph must meet minimum requirements for 9.99-second vehicles.� This means if you run quicker than 135 mph you must meet the requirements of NHRA chassis inspection, if automatic transmission a SFI 4.1 transmission shield, 30.1 flex plate shield & 29.1 flex plate. Also, NHRA license, Snell or SFI full-face helmet, SFI 3.2A/5 jacket and pants, SFI 3.3/1 gloves & neck collar. The same rules would apply if running E.T. bracket racing.
I was thinking about running my car in Stock Eliminator. What class would my 1965 Nova SS with a 283 cubic inch motor that was rated at 220 horsepower from the factory fall into with an automatic transmission?
I will walk you through how a Stock Eliminator vehicle is classified. Go to www.nhra.com and to the right, click on Competition and move your curser left in the dropdown menu to Stock Car Classification. Click on Chevrolet, click on 1965 and scroll down to page 5. Go to Nova SS Coupe 2 Dr and move to the right to 12.71 which is the Power to Weight factor for your body style and the 283/220 original hp that was factored to 223hp on 1/1/08. By looking at section 10A, page 1 of the 2011 NHRA Rulebook the Power to Weight factor of 12.71 puts your combination into the natural class of J/SA. You can move up a class or down a class from your natural class. So you could run I/SA, J/SA or K/SA with your combination. To get the minimum weight of your car in J/SA the calculation is done as follows. Bottom of the J class is 12.50 X factored hp of 223 = 2787.5 lbs + 170 for driver = 2957.5 lbs. We round down to 5 lb increments so your minimum weight at the scales, after a run, with driver for J/SA is 2955 lbs. You can do the math for I/SA at the 12.00 lb class and K/SA for the 13.00 lb class.
I heard that in 2011 I will need an engine diaper on my 1969 Super Pro Camaro to run at my local NHRA Track.
I�m getting a number of phone calls on the requirements of an oil-retention device for ET Bracket Racing. In the 2011 NHRA Rulebook if you are running in ET Bracket Racing you are not required to have an oil-retention device as long as you are not running quicker than 7.50 in the 1/4-mile or 4.50 in the 1/8-mile. You need to check with your local NHRA Track to see if their rules require any type of oil-retention device, there are a number of tracks that do require oil-containment if running quicker than 9.99 in the 1/4-mile or 6.40 in the 1/8-mile before you can run. So again, make sure you check with your local track.
One of my racing buddies said he heard that I would need to replace my rollcage padding before I race in 2011. Is this correct?
In the 2011 NHRA Rulebook on page 5 of section 4A, E.T. Handicap Racing, Roll-Cage Padding it states �Beginning June 1, 2011, roll-cage padding meeting SFI Spec 45.1 mandatory on any vehicle running 9.99 (*6.39) and quicker. Padding must be used anywhere driver�s helmet may come in contact with roll-cage components.� This not only applies to E.T. Handicap Racing but to any class or vehicle that runs 9.99 (*6.39) or quicker. Looking at a racing parts catalog you can purchase a 3-foot piece of SFI Spec 45.1 Roll-Cage Padding for under $20.
I have been running my 1968 Pontiac GTO in F/SA for a number of years. I was told by an NHRA Tech Inspector that I need to install a head protector since I have low back seats. Is this correct?
Head Protector Harold
Head Protector Harold,
The NHRA Tech Inspector told you correctly. When you go to the 2011 NHRA Rulebook to Stock Eliminator section 10A, page 9, Roll-Cage Padding in the last sentence, See General Regulations 10:6. When you go to section 20, page 40, 10:6 Head Protector it states �In any car where a roll bar or roll cage is installed, a padded head protector must be provided at the back of the driver�s head and constructed in an attempt to prevent whiplash upon impact. It goes on to state in the last sentence �A seat that incorporates a reinforced head rest is permitted.� Head rest must be within 4-inches of driver�s helmet. The photo in General Regulations section 20, page 40 is a great example of padded head protector with a low back seat.
I�m installing a new fuel cell in the trunk of my Pro ET car. If I use an aluminum fuel cell will I still need to run a ground wire to it?
The 2011 NHRA Rulebook in the General Regulations section 20, page 4, 1:5 Fuel Systems, Tanks: the last sentence states �Nonmetallic fuel cells or tanks must be grounded to frame�. So to answer your question, an aluminum fuel cell is automatically grounded by mounting it to the frame and in turn no additional ground wire is required.