New Nitro Rules (1 Viewer)

[clwill]

A new rules update was posted on NHRA.com as of Friday. Some interesting changes (such as allowing NOS on diesels?), but there's a huge new section on the Nitro policy -- I presume as the result of "nitro-gate".

Several interesting changes, including a change to only allow nitro from an "on-site supplier" and that the only "on-site supplier" is currently VP Fuels. Also a long definition of the required Nitro chemistry. And a change from "shall be banned" to "may be banned".

 

[MM]

they made it mandatory to have a cover over the reverser.....no doubt a result of the Creasy Jr. accident

 

[Paul]

How about 100% nitro for Denver! I didn't expect to see 100% nitro ever again.

 

[DixonFan]

How about 100% nitro for Denver! I didn't expect to see 100% nitro ever again.

There is no such percentage...100%

 

[GregM784]

There is straight Nitro, but isn't pure nitro only 99.5%?

 

[ProNitro Pete]

actually the best Nitro Percentage I've seen is 99.98%
you really couldnt get better than that there isnt a 100%

 

[Paul]

99.5 or 99.98 rounds up to 100%

 

[big guy]

When they say 99.5 or 99.8 %,they are talking about purity not specific gravity.The specific gravity might read higher than 100 %.

 

[FC138fan]

A side question - I noticed in recent years a big difference in sound when two fuel cars are idling as they stage (between now and say 1998). Less cackle and popping, more of a rumble. I always thought this was due to less nitro.

Is it due to the nitro, or have they just evolved that newer sound (like higher rpm's or something). If it is due to the nitro, does that mean you (not me cause I cant be there) get to hear the old sound again in Denver?

 

[Muddy]

actually the best Nitro Percentage I've seen is 99.98%
you really couldnt get better than that there isnt a 100%

We used to put it in ice and raise the percentage above 100. Percentage is calculated at a specific temperature (don't remember what..I suffer from KRAFT). By lowering the temperature it would make the nitro denser and show a greater percentage on the hydrometer. The motor felt the difference for sure. Now I've about exausted my knowledge so don't you engineer types beat me up to bad

 

[twok4hd]

We used to put it in ice and raise the percentage above 100. Percentage is calculated at a specific temperature (don't remember what..I suffer from KRAFT). By lowering the temperature it would make the nitro denser and show a greater percentage on the hydrometer. The motor felt the difference for sure. Now I've about exausted my knowledge so don't you engineer types beat me up to bad

If that is the case you better buy a new way of testing your nitro. If your temperature/specific gravity chart is telling you are going over 100%, you better get a new chart. 100% nitro (which can never happen) is somewhere between 99.5 to 99.8%. That is because you can never get to 100% purity in the process in which it is made. Temperature does change density which changes the specific gravity, it does not have any affect on percentage.

 

[ProNitro Pete]

We used to put it in ice and raise the percentage above 100. Percentage is calculated at a specific temperature (don't remember what..I suffer from KRAFT). By lowering the temperature it would make the nitro denser and show a greater percentage on the hydrometer. The motor felt the difference for sure. Now I've about exausted my knowledge so don't you engineer types beat me up to bad

John, I understand, that's originally how Jim MacMonagle came up with the 103% that he hawks like a Snake Oil Salesman.
I am talking COA/ 99.98% purity and that is our plant analysis numbers on testing purity, the rest is water and acid.

What you are talking about is similar to ice bagging your manifold on a gas car before a race. Density

 

[Nitro4U]

Hi Pete,
Thanks for the Snake oil salesmen, your making me famous again, I appreciate that. 99.9 is and always will be the cleanest purest product available, less acid and water content. Specific gravity and density does make the differance. Any Questions? My My ain't that nice"
Always

 

["Chuck"]

A side question - I noticed in recent years a big difference in sound when two fuel cars are idling as they stage (between now and say 1998). Less cackle and popping, more of a rumble. I always thought this was due to less nitro.

Is it due to the nitro, or have they just evolved that newer sound (like higher rpm's or something). If it is due to the nitro, does that mean you (not me cause I cant be there) get to hear the old sound again in Denver?

The difference in sound you hear has a large part to do with advances in camshaft profiling over the past 10-15 years. Also the cars are using more overdrive and a higher fuel input volume than they were 10-15 years ago too. And with the decrease in percentage it makes the engine sound more aggresive because of the increased cylinder pressures and piston speeds from the fuel and the cam.

 

[Nitrohelper]

The difference in sound you hear has a large part to do with advances in camshaft profiling over the past 10-15 years. .......... piston speeds from the fuel and the cam.

Could you explain what the advances in camshaft profiling have been over the last 15 years? Do you mean more lift?
How much have the piston speeds changed at idle to make a sound difference?
The fuel flow at idle has doubled over the last 15 years because of the big mags,I believe more volume & less percentage would take away the cackle at idle. :confused

 

[Toejam]

Remember the cars are running just as much Nitro at 90% they were at 96-97%. They are just running more volume to make up that difference. Tipping the can in Denver will make up for a TON of lost horsepower due to the thin air.

 

["Chuck"]

Could you explain what the advances in camshaft profiling have been over the last 15 years? Do you mean more lift?
How much have the piston speeds changed at idle to make a sound difference?
The fuel flow at idle has doubled over the last 15 years because of the big mags,I believe more volume & less percentage would take away the cackle at idle. :confused

Im not positive on what exactly they are running as far as camshafts go, but ive heard from alot of people that the latest thing in top fuel right now is more duration and less overlap....it just makes the motor run alot smoother, plus the cams are more aggressive with alot more lift and higher rocker arm ratios to push the valve open farther...The piston speeds have changed alot with those changes because your putting more fuel into the motor hence it burns more and increases the ammount of cylinder pressure which pushes the piston down in the cylinder alot harder....Im sure some other people here in this forum have more information than i do in that department.