Alex, you're making my head dizzy.

 

Sorry sir.

 

Yes, it is wrong.

1) It's degrees Celcius, not Fahrenheit
2) Only the second fraction is taken to ^0.5. It's not multiply the fractions by 0.95.

Look at the equation again.

 

That's great, however, with the equation I've been taught to use, you utilize F, not C, and multiply time .95. And I verified my equation with another place, another time, last year, on my350z.com, when we dyno'd a bunch of local Zs, including mine, following the same formula (mine), the cf ended up being 1.02. When input the correct information from the site you posted (date/time info) on that date, the cf comes out the same. So, even you are using your formula, using MY formula, the correct CF still comes out, given my equation, which tells me that the equation I've been given is correct.
Next.

 

Well I don't see how it's possible for your formula to work because the 273 in the equation specifically relates to Celcius not Farhenheit. You can't simply interchange the two. I simply posted the accepted SAE correction factor equation used by nearly every dyno shop and engine tuner in the world. If you or certain groups choose to use a different CF, then so be it. I'll choose to stick with what is widely accepted.

I really don't understand how you can say your CF is just like the SAE CF. For the same given conditions, they both generate two entirely different sets of numbers, your's of which increases the numbers quite heavily.

On a 65 degree day, the SAE CF is right around 1.00-1.01 where as your CF equation is suggesting a 1.05-1.06. On a G35 that could mean the difference between saying the same car/same day is making 210whp or it's making 223whp. You don't see a problem with this?

 

That's absolutely great Dave, however, the formula works. If you like, I have no problem posting the same type of information (using the equation I've been taught to work with), and I guarantee that the CF thru the calculation will match the "average" numbers input next time. For that matter, we will be retesting my car with some new mods shortly, so the equation I showed you, just like it has done so in the past, will turn out to be correct.

 

By the way, I didn't write or invent this equation, I am simply showing you how it was shown to me, and how it works (succesfully).

 

Maybe you should question it and where these people pull these numbers from.

 

You forgot a few continents, namely Europe and Asia....they don't care about BHP and generally use the DIN correction or ISO in lieu of the SAE-J1349 that you are referring to.

NOW slag off.

 

When it comes down to the nut cuttin' the only thing that matters is a stopwatch. Put em' on a track. HP this TK that. It's all talk untill you lay some rubber.

 

Unlike you, I am satisfied with things that make sense. Now, as my first response to you begged, just leave this thread alone. Your negativity has been getting on nerves of many people, and I personally think you'd never be satisfied with anything.

 

Thank you. I was feeling a bit alone in this thread.

 

But DaveB will ask the following....barometric pressure, vapor pressure, time of day, sunlight position, color of your underwear, how many pieces of anything you have in the trunk. And when you finish racing, if he loses, he'll tell you that it was unfair because the rainbow went over the track, affecting the barometric pressure of the initial downdraft versus the other lane, and how the thickness of the cement was one of factors of his loss, etc, etc, etc.....

 

Reminds me of a time back in High School, a friend had a 72' Beetle. Box stock, no air, no nuttin'. However, it was what you call a "factory freak". It ran 17.84 in the 1/4 mile (I know, but for a stock bug in 72' that was fast) and top out at over 110MPH. This guy with a 71' beetle that had headers, re-jetted carb, etc. wanted to run. So we headed out to a lonely road to race. On the way we passed him up on the road. You could see him yelling in his fancy bug. When we got to the spot he waved us over to a parking area. He jumped out with a bayonet (yes a WW2 bayonet) in his hand. "Open up that hood, RIGHT NOW!" he screamed. So we did, and there it was, a box stock beetle motor. He said, "thats impossible, you can't beat me!" Jimmy had just had it in for the 6000 mile service. We had the tech report to show him with engine compression on all four. He ripped the plug wires out of the distributor and left in a huff. We just laughed.

 

No, I completely agree with Texasscout, the track is where you can prove which car is actually faster assuming the cars are running at the same track and the same day. The trapspeeds with reveal the truth. However, comparing what Joe Blow ran at ATCO and what Jimmy Dean ran at Englishtown is a worthless comparison. All tracks are different. Also, you are correct, correcting your ET/MPH to density altitude, assuming the same track, will allow to determine if your mods and/or driving is improving things.

Whether you choose to correct to DA is up to you. It's easy to do and it can easily tell if it was the conditions or the mods that allowed your car to run faster/slower. If I had a dollar for every person that attributed their gains to mods instead of great weather conditions, I'd be a rich man.