how much affect dose RA have on qtr times?

when my car had 159 rwk@5300 /322nm @3400 i ran a 14.597 @94.9 with an RA reading of 934
the car now makes 158rwk @5400 /340 nm . last time i was at willow the best i ran was 15.478 @91.1 with an RA reading of 3133.
how much dose the RA readings affect your qtr mile times /trap speed?
thanks ,jake

[Craig]

I reckon you have answered your own question Jake. The lower the RA reading the better in most cases, sometimes when it is too low the air is real thin and creates moisture on the racetrack. Willowbank is pretty bad for that. The old Ravenswood racetrack in WA was always around the 400 or even lower and you can make some nice horsepower. Adelaide is a sea level track and was always very good if the traction was there.

Mosr cars will run better at night when it has cooled off....

Whats an RA reading.?

[Quadcams]

Originally Posted by Stampy

Whats an RA reading.?

RA= relative altitude
Its a scale of the quality of the air, a combination of humidity, air temp, barometric pressure and a height at which the readings were taken.

Heres a site with a RA calculator http://wahiduddin.net/calc/calc_da_rh.htm , this site will explain it all.

To use calculator you must know the height at which the reading was taken, for example WSID is at 230ft then the rest of the info is on your time slip.

Ive noticed every 1000ft drop in RA you gain roughly about .15 drop on ET and a bit over 1mph in power well in my case anyway.

[Quadcams]

Originally Posted by Nik

when my car had 159 rwk@5300 /322nm @3400 i ran a 14.597 @94.9 with an RA reading of 934
the car now makes 158rwk @5400 /340 nm . last time i was at willow the best i ran was 15.478 @91.1 with an RA reading of 3133.
how much dose the RA readings affect your qtr mile times /trap speed?
thanks ,jake

Going from 3133 RA to 934 RA you would roughly gain atleast 3mph and .3 maybe more off ET also check your 60' between the 2 times possible had a slower launch on the 15.4 aswell.

Maybe try this correction calculator http://www.xs-fx.com/pain/ws.htm I dont know how accurate it is but it makes you smile. :

when you use this put in the temps when you did your good time and you will see what it would do in the same air quality.

Originally Posted by Lowride260

Going from 3133 RA to 934 RA you would roughly gain atleast 3mph and .3 maybe more off ET also check your 60' between the 2 times possible had a slower launch on the 15.4 aswell.

Maybe try this correction calculator http://www.xs-fx.com/pain/ws.htm I dont know how accurate it is but it makes you smile. :

when you use this put in the temps when you did your good time and you will see what it would do in the same air quality.

i did a much slower 60ty when i ran the 15.4 it was 2.393 compared to 2.065 .i was more concerned with the mph , but buy the sounds of it ,it should be still on the money.
i tried using the cailculator but it wouldn't let me do it .
i was just surfing through the time slips and seen willowbank gets down to -100+ ra in the winter .
thanks for the info