Additive

[flapjack]

I noticed that when a crew member is mixing up the nitro, they draw from
a drum that apparently is premixed as I do not see them add methanol after
the draw. Then I see the solution mix using a compressed air gun. Then the
hydrometer to check that the nitro level is 90% or less. But the thing that got
me is the crew member added a splash of something, and based on what I
saw them put in amount-wise, I doubt it was methanol (too little to affect the
percentage).

Does any one know what this is? A stabilizer of some sort, to keep the nitro
and methanol mixed together?

 

[handsome]

they aren't allowed additives. in a 15 gallon or so tank, it won't take much to change the nitro percentage if you want to reduce it just a couple percent and a couple percent can make a difference in the tune up

 

[The Counterfeiter]

But the thing that got me is the crew member added a splash of something, and based on what I
saw them put in amount-wise, I doubt it was methanol (too little to affect the
percentage).Does any one know what this is? A stabilizer of some sort, to keep the nitro and methanol mixed together?

I don't know if this is still used, and I got a lesson when Baca literally smeared it on my nose several years ago -
But . . . It could be NitroGlide, which is a lubricant for (I think) the blower.
If I'm wrong, feel free to correct me. Just don't bring up very embarrassing history! -

 

[flapjack]

I did some calculations. If you start with 5 gallons of 90% nitromethane, 10% methanol and add 1 pint of methanol to the mix, the resulting mix is 87.8% nitromethane and 12.2% methanol. But I am still not convinced they are adding methanol to the premix.

 

[twostep]

I did some calculations. If you start with 5 gallons of 90% nitromethane, 10% methanol and add 1 pint of methanol to the mix, the resulting mix is 87.8% nitromethane and 12.2% methanol. But I am still not convinced they are adding methanol to the premix.

They might not be...but again, they might. They're allowed 90 percent but that varies, depending on track conditions and their particular combination. It's part of the tuneup, the same as blower overdrive and timing.

 

[TF CREW]

I did some calculations. If you start with 5 gallons of 90% nitromethane, 10% methanol and add 1 pint of methanol to the mix, the resulting mix is 87.8% nitromethane and 12.2% methanol. But I am still not convinced they are adding methanol to the premix.

It dosent quite work that way it is based the specific gravity of the liquid @ 60 degrees. THERE ARE NO ADDITIVES ALLOWED! Either methanol is added to lower the percentage or more nitro is added to increase the number up to NHRA's maximum of 90 percent.

One degree difference can change the reading by up to a quarter percent, so having the fuel at exactly 60 degrees is critical. If the nitro is just a few degrees cold, I can usually warm it by holding the beaker in my hands. If I need to go higher, I'll get a heat gun. If I need to cool it, I'll stick the beaker in a bucket of ice."

 

[BaldyLochs]

For sure - fuel additives WILL make you go faster - faster into your trailer, that is. Unless I am wrong, I believe NHRATech fuel-samples every professional car on Raceday; or do they hit them all on qualifying days as well?

 

[Toejam]

What about Power mist?

 

[flapjack]

It dosent quite work that way it is based the specific gravity of the liquid @ 60 degrees. THERE ARE NO ADDITIVES ALLOWED! Either methanol is added to lower the percentage or more nitro is added to increase the number up to NHRA's maximum of 90 percent.

One degree difference can change the reading by up to a quarter percent, so having the fuel at exactly 60 degrees is critical. If the nitro is just a few degrees cold, I can usually warm it by holding the beaker in my hands. If I need to go higher, I'll get a heat gun. If I need to cool it, I'll stick the beaker in a bucket of ice."

No offense, but wow, that is old school! From what I have seen, people are starting to use digital hydrometers which have automatic temperature correction. No more heating or cooling the mix to 60 degrees before taking a reading or doing a manual computation for temperature correction.

Now what I don't get is how the specific gravity is turned into a percentage. Is that there is a specific gravity G for 100% nitromethane @ 60 degrees, and then there is a specific gravity S for some unknown nitromethane and methanol solution, and the percentage is calculated as (S/G)*100?

 

[TF CREW]

The Digital Hydrometers are about $3500 a traditional one is about $120.

FUEL TEST CHART
Test hydrometer reads 100% at 68° in known pure nitro.

TEMPERATURE OF FUEL- (°F)
40° 50° 60° 68° 70° 80° 90° 100° 110° 120

True % Nitro

100 - 106 104 102 100 99 97 94 92 90 87

98 - 104 102 100 98 97 95 93 90 88 86

90 - 97 94 92 90 89 87 85 83 80 78

80 - 86 83 82 80 80 77 75 73 70 68

70 - 75 73 71 70 70 68 65 63 61 59

60 - 66 63 61 60 60 58 56 54 52 50

50 - 55 53 51 50 49 48 46 44 42 40

40 - 45 43 41 40 39 37 35 33 31 30

30 - 35 33 31 30 29 27 25 23 22 20

20 - 27 25 22 20 20 18 17 15 13 11

10 - 20 16 13 10 10 9 7 5 3 1


EXTREMES of temperature can play havoc with nitromethane power output and provide for false hydrometer test readings. Graph above shows the effects of temperature changes on nitro-completely accurate readings can only be obtained with fuel at 68 degrees Fahrenheit.

 

[turbo ken]

We have the beaker type hydrometer that has markings on it so you can figure out the % based on the ambient temperature, it's not hard to figure it out in your head.

 

[flapjack]

The Digital Hydrometers are about $3500

Holy sh*t, I had no idea...

 

[flapjack]

We have the beaker type hydrometer that has markings on it so you can figure out the % based on the ambient temperature, it's not hard to figure it out in your head.

I majored in mathematics, so naturally, I am terrible at doing computations in my head.

 

[Tim5636sc]

For sure - fuel additives WILL make you go faster - faster into your trailer, that is. Unless I am wrong, I believe NHRATech fuel-samples every professional car on Raceday; or do they hit them all on qualifying days as well?

The policy is to pull a sample on every car on every National Event lap. It is then measured for temp, and specific gravity. Out of the entire field, (4) cars are randomly selected and the sample is sent to "The Lab" where Jim Collins or another NHRA Fuel guy runs it through a specro-analysis machine, comparing it against a 'BASE' sample. The policy is used in eliminations and qualifying.

In Pro Stock, if you are in the top 10, NHRA fills you up. If not, you run your own fuel in qualifying.

As far sportsman, the policies are slightly different. The A/Fuel cars are 'temped' in the staging lanes to ensure they are over 50 degrees F. They are then fuel checked and temped at the top end, on every pass. Not sure what the Alky guys policy is....but they sure do BABYSIT the A/Fuelers pretty well...

 

[TF CREW]

The policy is to pull a sample on every car on every National Event lap. It is then measured for temp, and specific gravity. Out of the entire field, (4) cars are randomly selected and the sample is sent to "The Lab" where Jim Collins or another NHRA Fuel guy runs it through a specro-analysis machine, comparing it against a 'BASE' sample. The policy is used in eliminations and qualifying.

In Pro Stock, if you are in the top 10, NHRA fills you up. If not, you run your own fuel in qualifying.

As far sportsman, the policies are slightly different. The A/Fuel cars are 'temped' in the staging lanes to ensure they are over 50 degrees F. They are then fuel checked and temped at the top end, on every pass. Not sure what the Alky guys policy is....but they sure do BABYSIT the A/Fuelers pretty well...

Tim I dont always go to the top end these days but if I am not mistaken but I could be wrong fuel samples are pulled first session then only if you advance IE; improve on qualifing time and advance in eliminations.

 

[The Counterfeiter]

Well . . . Nitroglide is still out there, a VP product. Don't know if this is what you saw, but note that it does mix with nitromethane!

VP Nitroglide

 

[Tim5636sc]

Tim I dont always go to the top end these days but if I am not mistaken but I could be wrong fuel samples are pulled first session then only if you advance IE; improve on qualifing time and advance in eliminations.

I missed that part... you are correct. ONLY if you improve or win a round are you required to stop off at fuel check.

 

[Tom]

I missed that part... you are correct. ONLY if you improve or win a round are you required to stop off at fuel check.

Have any of you checked the fuel after a run. It averages at least a 2% drop due to the methanol evaporation.

 

[TF CREW]

Have any of you checked the fuel after a run. It averages at least a 2% drop due to the methanol evaporation.

Yes It also depends on where its drawn from. I ve had the situation where the tank and lines were dry and pulled it from the fuel rails