Welcome to the Australian Ford Forums forum.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and inserts advertising. By joining our free community you will have access to post topics, communicate privately with other members, respond to polls, upload content and access many other special features without post based advertising banners. Registration is simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact us.

Please Note: All new registrations go through a manual approval queue to keep spammers out. This is checked twice each day so there will be a delay before your registration is activated.

Go Back   Australian Ford Forums > MotorSport > Drag Racing

Drag Racing Discuss Drag Racing here be it dirt or tarmac. Sponsored by Sydney Dragway.

Reply
 
Thread Tools Display Modes
Old 03-02-2006, 09:01 AM   #1
Nik
Guest
 
Posts: n/a
Default 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

  Reply With Quote Multi-Quote with this Post
Old 03-02-2006, 10:09 AM   #2
Craig
RIP Craig - 13/11/08
Donating Member1
 
Craig's Avatar
 
Join Date: Feb 2005
Location: Kilmore, 30 minutes from Heathcote Raceway
Posts: 3,571
Default

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....
Craig is offline   Reply With Quote Multi-Quote with this Post
Old 03-02-2006, 11:14 AM   #3
Stampy
Guest
 
Posts: n/a
Default

Whats an RA reading.?
  Reply With Quote Multi-Quote with this Post
Old 03-02-2006, 04:25 PM   #4
Quadcams
FF.Com.Au Hardcore
 
Quadcams's Avatar
 
Join Date: Jan 2005
Location: Working, chasing after my daughter and working
Posts: 3,407
Default

Quote:
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 is offline   Reply With Quote Multi-Quote with this Post
Old 03-02-2006, 04:38 PM   #5
Quadcams
FF.Com.Au Hardcore
 
Quadcams's Avatar
 
Join Date: Jan 2005
Location: Working, chasing after my daughter and working
Posts: 3,407
Default

Quote:
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.

Last edited by Quadcams; 03-02-2006 at 04:44 PM.
Quadcams is offline   Reply With Quote Multi-Quote with this Post
Old 03-02-2006, 10:39 PM   #6
Nik
Guest
 
Posts: n/a
Default

Quote:
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
  Reply With Quote Multi-Quote with this Post
Reply


Forum Jump


All times are GMT +11. The time now is 01:40 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Other than what is legally copyrighted by the respective owners, this site is copyright www.fordforums.com.au
Positive SSL