Dave, it's unfortunate your thread was tainted with some extremely INACCURATE facts about humid air being more dense. (i mean holy crap, you learn that the more humid air is the less dense it is, in f*cking high school. issac newton mean anything to anyone? i'm glad some people with backgrounds in physics stepped in!)

unfortunately, this takes away from the credibility of your thread and your claims and those claims of your friends. however, you dyno'd about what I'd expect you to dyno. this does not, however, make you a low 13 second car.

you're making about 15whp more than a stock S2000. and about 15lb/ft (to the wheels) more than a stock S2000. I'm glad you went and got a dyno done on a dynojet, as I think it shows some credibility for you finally. it's unfortunate it got ruined by people arguing that humid air makes more power cuz it's more dense. (ugh, that's scary to think that people you thought were more knowledgeable would say such things! )

but 15whp and 15lb/ft won't put you into low 13's. Maybe mid 13's at best if you're one hell of a driver. giving you benefit of the doubt, I think at sea level or close to sea level, you'd be able to get in the 13.5 (mid 13) range.

 

a quick excerpt from princeton university:

[QUOTE] Most people who haven't studied physics or chemistry find it hard to believe that humid air is lighter, or less dense, than dry air. How can the air become lighter if we add water vapor to it?

Scientists have known this for a long time. The first was Isaac Newton, who stated that humid air is less dense than dry air in 1717 in his book, Optics. But, other scientists didn't generally understand this until later in that century.

To see why humid air is less dense than dry air, we need to turn to one of the laws of nature the Italian physicist Amadeo Avogadro discovered in the early 1800s. In simple terms, he found that a fixed volume of gas, say one cubic meter, at the same temperature and pressure, would always have the same number of molecules no matter what gas is in the container. Most beginning chemistry books explain how this works.

Imagine a cubic foot of perfectly dry air. It contains about 78% nitrogen molecules, which each have a molecular weight of 28 (2 atoms with atomic weight 14) . Another 21% of the air is oxygen, with each molecule having a molecular weight of 32 (2 stoms with atomic weight 16). The final one percent is a mixture of other gases, which we won't worry about.

Molecules are free to move in and out of our cubic foot of air. What Avogadro discovered leads us to conclude that if we added water vapor molecules to our cubic foot of air, some of the nitrogen and oxygen molecules would leave

 

Any time, go change some oil.

 

Yup, squeezing.

If you look at his numbers given the altitude and temperature that day a corrected sea level run would have netted somewhere near 250 rear wheel -- which we all know is complete bullshit unless he has the most magical S2000 in the world as no one has even come CLOSE to those numbers, let alone with 3 mods.

Then we have the pre VTEC horsepower bump -- and the way too lean A/F ratio and the fact that we know Vegas has a NOx setup and wants desperatly to regain some manner of the credability he has slowly pissed away with his fabricated bullshit ...

 

[QUOTE=S2oooNvegas,Feb 13 2006, 11:22 AM] uhm, no smart guy.

 

Go steve GO.....

I was wondering about the "bump". I don't have it and I haven't seen it on any other NA S2000's. Come to think of it, I've only seen it on a NOS dyno.

 

Thanks for bringing this up Kumar.

Here's a good site regarding power correction factors.

The relevant portion is reposted below:


[I]Power Correction Factors

The power output of an internal combustion engine is significantly influenced by barometric pressure, ambient air temperature, and air humidity.

Lower ambient barometric pressure reduces the density of the air, thus reduces the amount of oxygen filling the cylinder for each cycle, resulting in lower power output. Conversely, higher barometric pressure increases power.

Lower ambient air temperature results in increased density of the air, thus increases the amount of oxygen filling the cylinder for each cycle, resulting in higher power output. Conversely, higher air temperature reduces power output.

Lower air humidity (less water vapor) leaves more room for oxygen per cubic foot of air, thus increases the amount of oxygen filling the cylinder for each cycle, resulting in higher power output. Conversely, higher air humidity reduces power output.

Several Standards organizations have determined methods for estimating engine power under reference conditions. The best known organizations are:

ISO (International Standards Organization), worldwide
SAE (Society of Automotive Engineers), USA
ECE (European Community), Europe
JIS (Japanese Institute for Standardization), Japan
DIN (Deutsche Industrie Norm), Germany

There are power correction standards for gasoline and Diesel engines, for applications in road vehicles, stationary engines, or marine engines, etc. For a motorcycle dynamometer, relevant standards are those generally intended for gasoline engines in road vehicles and those specific to motorcycles.

Power correction standards try to estimate what engine power would be under reference conditions. They cannot actually calculate exactly what power output would be. The greater the difference between the ambient conditions during the test and the reference conditions, the greater the error in the estimate. Most power correction standards include limits on their applicability. This limit is typically +/- 7%. This means if the correction factor is greater than (>) 1.07 or less than (<) 0.93, the corrected power numbers are not officially considered to be acceptable, and the test should be performed again under conditions which are closer to the reference conditions.

For private applications this is less of a problem, and the corrected power numbers are still the best basis for comparisons. However, please keep this into consideration when comparing test results obtained under considerably different test conditions.

Power corrections are only valid for Wide Open Throttle (WOT) tests. You should disregard corrected power numbers for any test performed under partial throttle conditions. The default configurations supplied with the CycleDyn system include power corrections to the following standards: SAE, STP, ECE, DIN.

SAE -- The SAE standard applied is a modified version of the SAE J1349 standard of June 1990. Power is corrected to reference conditions of 29.23 InHg (99 kPa) of dry air and 77 F (25

 

: nice.

 

Hmmm, also a decent point.


one thing i'm curious about is the 14.67 AFR. Our cars would detonate on such an AFR. And assuming you didn't just very recently add on some mods that would make the AFR spike like that, our ECU (over a little time) would see this condition and correct for it by upping the injector pulse to compensate.

While I like to give the benefit of the doubt, it does make a case to argue that nitrous was used, given the AFR and your altitude. However, again, I like to give benefit of the doubt, so if you have an explination dave, i'm all ears to hear your side!

 

[QUOTE=gary_phd,Feb 13 2006, 12:39 PM]
[COLOR=red]STP -- The STP (also called STD) standard is another power correction standard determined by the SAE. This standard has been stable for a long time and is widely used in the performance industry. Power is corrected to reference conditions of 29.92 InHg (103.3 kPa) of dry air and 60 F (15.5