First 1/4 mile ever results.
08-25-2017, 03:38 PM
#23
Burning Brakes
You can use the Drag Times DA calculator to find out the exact density altitude at the time of your run, and then run a (admittedly less-than-accurate) correction in order to see what the times would have been at sea level density altitude.
For you 11.05 run...
At Cedar Falls Raceway which is at 1013 foot altitude, at 3:35pm on Aug 20, 2017, the temperature was 82.4 degrees F, barometer at 29.95 inches mercury, and 54% relative humidity, the density altitude was 2971 feet.
With this data, the 11.051 ET at 126.67 mph trap speed, this corrects to (approximately):
Stock and Mildly Modified Naturally Aspirated Engines
10.657 @ 131.445 MPH
Extensively Modified Naturally Aspirated Engines
10.776 @ 129.999 MPH
Extensively Modified Supercharged and Turbocharged Engines
10.897 @ 128.447 MPH
Sources:
DA calculation:
http://www.dragtimes.com/da-density-...time=3:35%20PM
Speed and ET calculation:
http://www.dragtimes.com/da-density-...ect+ET+and+MPH
For you 11.05 run...
At Cedar Falls Raceway which is at 1013 foot altitude, at 3:35pm on Aug 20, 2017, the temperature was 82.4 degrees F, barometer at 29.95 inches mercury, and 54% relative humidity, the density altitude was 2971 feet.
With this data, the 11.051 ET at 126.67 mph trap speed, this corrects to (approximately):
Stock and Mildly Modified Naturally Aspirated Engines
10.657 @ 131.445 MPH
Extensively Modified Naturally Aspirated Engines
10.776 @ 129.999 MPH
Extensively Modified Supercharged and Turbocharged Engines
10.897 @ 128.447 MPH
Sources:
DA calculation:
http://www.dragtimes.com/da-density-...time=3:35%20PM
Speed and ET calculation:
http://www.dragtimes.com/da-density-...ect+ET+and+MPH
08-25-2017, 08:31 PM
#24
Pro
Thread Starter
You can use the Drag Times DA calculator to find out the exact density altitude at the time of your run, and then run a (admittedly less-than-accurate) correction in order to see what the times would have been at sea level density altitude.
For you 11.05 run...
At Cedar Falls Raceway which is at 1013 foot altitude, at 3:35pm on Aug 20, 2017, the temperature was 82.4 degrees F, barometer at 29.95 inches mercury, and 54% relative humidity, the density altitude was 2971 feet.
With this data, the 11.051 ET at 126.67 mph trap speed, this corrects to (approximately):
Stock and Mildly Modified Naturally Aspirated Engines
10.657 @ 131.445 MPH
Extensively Modified Naturally Aspirated Engines
10.776 @ 129.999 MPH
Extensively Modified Supercharged and Turbocharged Engines
10.897 @ 128.447 MPH
Sources:
DA calculation:
http://www.dragtimes.com/da-density-...time=3:35%20PM
Speed and ET calculation:
http://www.dragtimes.com/da-density-...ect+ET+and+MPH
For you 11.05 run...
At Cedar Falls Raceway which is at 1013 foot altitude, at 3:35pm on Aug 20, 2017, the temperature was 82.4 degrees F, barometer at 29.95 inches mercury, and 54% relative humidity, the density altitude was 2971 feet.
With this data, the 11.051 ET at 126.67 mph trap speed, this corrects to (approximately):
Stock and Mildly Modified Naturally Aspirated Engines
10.657 @ 131.445 MPH
Extensively Modified Naturally Aspirated Engines
10.776 @ 129.999 MPH
Extensively Modified Supercharged and Turbocharged Engines
10.897 @ 128.447 MPH
Sources:
DA calculation:
http://www.dragtimes.com/da-density-...time=3:35%20PM
Speed and ET calculation:
http://www.dragtimes.com/da-density-...ect+ET+and+MPH
Information about Cedar Falls Raceway
address:7227 Waverly Rd, Cedar Falls, IA 50613
- -track elevation: 889.1 ft
- -track lat, long: 42.5997, -92.4592
- -online: website
Facebook Post
- -Hours of daylight: 13:23:56
- -Sunrise: 06:29:24 am 08/26/17
- -Sunset: 07:53:20 pm 08/26/17
09-12-2017, 02:01 AM
#25
Team Owner
You can use the Drag Times DA calculator to find out the exact density altitude at the time of your run, and then run a (admittedly less-than-accurate) correction in order to see what the times would have been at sea level density altitude.
For you 11.05 run...
At Cedar Falls Raceway which is at 1013 foot altitude, at 3:35pm on Aug 20, 2017, the temperature was 82.4 degrees F, barometer at 29.95 inches mercury, and 54% relative humidity, the density altitude was 2971 feet.
With this data, the 11.051 ET at 126.67 mph trap speed, this corrects to (approximately):
Stock and Mildly Modified Naturally Aspirated Engines
10.657 @ 131.445 MPH
Extensively Modified Naturally Aspirated Engines
10.776 @ 129.999 MPH
Extensively Modified Supercharged and Turbocharged Engines
10.897 @ 128.447 MPH
Sources:
DA calculation:
http://www.dragtimes.com/da-density-...time=3:35%20PM
Speed and ET calculation:
http://www.dragtimes.com/da-density-...ect+ET+and+MPH
For you 11.05 run...
At Cedar Falls Raceway which is at 1013 foot altitude, at 3:35pm on Aug 20, 2017, the temperature was 82.4 degrees F, barometer at 29.95 inches mercury, and 54% relative humidity, the density altitude was 2971 feet.
With this data, the 11.051 ET at 126.67 mph trap speed, this corrects to (approximately):
Stock and Mildly Modified Naturally Aspirated Engines
10.657 @ 131.445 MPH
Extensively Modified Naturally Aspirated Engines
10.776 @ 129.999 MPH
Extensively Modified Supercharged and Turbocharged Engines
10.897 @ 128.447 MPH
Sources:
DA calculation:
http://www.dragtimes.com/da-density-...time=3:35%20PM
Speed and ET calculation:
http://www.dragtimes.com/da-density-...ect+ET+and+MPH
09-13-2017, 12:04 PM
#28
Le Mans Master
He's just trying to say that DA correcting for different days and tracks isn't accurate, which you know already.
Your car may make more power on another day but that doesn't guarantee it will run quicker.
Some stellar air days don't yield the best times because traction became an issue.
Typically this is more of an issue with a manual and a traction limited real wheel drive car.
There are so many factors that play a role in all of this and that's why, for this drag racing hobby, my moto is you need to actually run the time on a legit track to claim what the car/setup can run.
Your car may make more power on another day but that doesn't guarantee it will run quicker.
Some stellar air days don't yield the best times because traction became an issue.
Typically this is more of an issue with a manual and a traction limited real wheel drive car.
There are so many factors that play a role in all of this and that's why, for this drag racing hobby, my moto is you need to actually run the time on a legit track to claim what the car/setup can run.
09-13-2017, 01:05 PM
#29
Burning Brakes
Right, and tis why I mentioned approximately, and how it's not entirely accurate. But to say that "track prep is affected by altitude" is just... wrong.
The correction factor is simply a "given the same conditions, same track prep, same amount of traction, same stomp off the line, same weight in the gas tank, same everything except at sea level altitude, you'd run approximately this fast."
The correction factor is simply a "given the same conditions, same track prep, same amount of traction, same stomp off the line, same weight in the gas tank, same everything except at sea level altitude, you'd run approximately this fast."
09-13-2017, 01:38 PM
#30
Le Mans Master
Right, and tis why I mentioned approximately, and how it's not entirely accurate. But to say that "track prep is affected by altitude" is just... wrong.
The correction factor is simply a "given the same conditions, same track prep, same amount of traction, same stomp off the line, same weight in the gas tank, same everything except at sea level altitude, you'd run approximately this fast."
The correction factor is simply a "given the same conditions, same track prep, same amount of traction, same stomp off the line, same weight in the gas tank, same everything except at sea level altitude, you'd run approximately this fast."
Altitude doesn't affect track prep, but it does affect the amount of power you produce, whereas the amount of power a given track prep will hold is a constant. Thus, one changes relative to the other.
09-13-2017, 01:42 PM
#31
Burning Brakes
As somebody who does live in Denver, and somewhat of a striprat, I can tell you now that when it comes to the DA correction factor, its simply saying all other factors being the same, except altitude, this is what you'd approximately run.
This is not a difficult concept to grasp.
This is not a difficult concept to grasp.
09-13-2017, 01:59 PM
#32
Le Mans Master
That's what I thought, but apparently...
I'll try one more time. I'll use round numbers for simplicity.
Track will hold an 11.0
Your car runs an 11.5 in super thin air, DA corrected to a 10.5
Your car would not -really- run a 10.5 in better air because the track could not hold it
I'll try one more time. I'll use round numbers for simplicity.
Track will hold an 11.0
Your car runs an 11.5 in super thin air, DA corrected to a 10.5
Your car would not -really- run a 10.5 in better air because the track could not hold it
Last edited by davepl; 09-13-2017 at 02:01 PM.
09-13-2017, 03:50 PM
#33
Burning Brakes
/Facepalm
That is not at all how the DA adjustment works. I've described the adjustment twice, obviously you just aren't getting it, and I'm not sure how I can make it any clearer. I give up.
That is not at all how the DA adjustment works. I've described the adjustment twice, obviously you just aren't getting it, and I'm not sure how I can make it any clearer. I give up.
09-13-2017, 06:09 PM
#34
Le Mans Master
If you are claiming that "all other factors held constant, this is the ET you'd run at sea level", you're just dead wrong. And not just a little bit.
Last edited by davepl; 09-13-2017 at 06:13 PM.