So, what are ideal track conditions?

[DGthe3]

Just thought I'd post up this question because there is a lot of talk about poor conditions but I'm sure there are a lot of members on here who either don't know know for sure, or don't have any idea at all.

[Rock36]

Ideal track conditions would be something along the lines of having a density altitude (DA) of 0 ft or less.

A perfectly level track with no wind, especially no headwind.

And a well preppred launch pad with enough traction compound to limit wheel spin like:

http://www.bazellracefuels.com/strip...n_compound.htm
http://www.jegs.com/i/VHT/870/SP162/10002/-1

[Phenix]

^^^what he said

Also people might wonder what's this density altitude jargon...

Some brainiacs in a land far far away long ago decided to determine a "standard atmosphere." They did this so that you can have a standardized starting point when measuring the performance of anything that is affected by the atmosphere, in our case here that's engines (this same standard is used in aviation and aerospace btw, as a pilot I have to deal with it for every flight). So... what is standard atmosphere you ask?
Air pressure: 29.92" Hg
Air temperature: 15*C (about 59*F)
Humidity: 0%
Wind: none

Remember that this standard is rather arbritrary as you'll likely never encounter these actual conditions, but it gives you a place to measure from, kind of like zeroing out the scale, when you apply a mathematical correction to the actual conditions.

If you do infact find that the weather does match standard atmosphere your DA = the actual track elevation. Without going through all the calculations (there's plenty of free calculators online that make it a lot easier) this is what makes DA higher than track elevation:
Lower pressure
and/or
Higher temp
and/or
higher humidity

[Rock36]

Yeah I forgot to mention temperatures too. You need a bit of a balance. Cool enough so that the engine is breathing well and not heating up too much, but warm enough that the rubber and asphalt don't loose traction.

Typically I've found temps in the upper 50s/low 60s to be the best.

[DGthe3]

Originally Posted by Rock36

Yeah I forgot to mention temperatures too. You need a bit of a balance. Cool enough so that the engine is breathing well and not heating up too much, but warm enough that the rubber and asphalt don't loose traction.

Typically I've found temps in the upper 50s/low 60s to be the best.

Optimum would therefore be in the evening after a warm day ... cold dense air for the engine with a track that still provides a lot of grip

[patriotpa]

Ideal track conditions are clear, cool, sunny weather.


...and no one on the track faster than you!

[Rock36]

Originally Posted by DGthe3

Optimum would therefore be in the evening after a warm day ... cold dense air for the engine with a track that still provides a lot of grip

Good point...

[Nine Ball]

Best conditions for drag racing would typically be:

45-55 F temperatures. Any colder and the tires do not hook as well.
No head wind. A tail wind helps with MPH!
High barometric pressure. Anything over 30.0 inHg is good.
Low low humidity. Less than 20% is excellent.

Once your Density Altitude goes below 0 feet, that is excellent drag racing weather. It doesn't happen often, and what sucks is that most tracks close in the winter when we do see negative DA. With most tracks only being open 2 days a week, the odds of it being open on a negative DA day are even less. Those are also the most crowded days