383ss Posted January 27, 2004 Report Share Posted January 27, 2004 Ok, I've been talking about density altitude in a few other threads. I thought I'd show you who don't know how to figure it out and how to correct it to 0 so you can actually see how much mods really help you out. Nothing worse then buying a mod and trying it out in completely different weather conditions then your last run and not getting a good comparision of what you gained. First you need to get the weather conditions of the track when you ran and the altitude of the track. this site will give you a minute by minute history as far back as you want to go. you can find this at: http://www.weatherunderground.com then input the values into this calulator: http://wahiduddin.net/calc/calc_hp_dp.htm now reference this graph to calculate your density altitude to 0 for a fair comparison: http://www.gnttype.org/techarea/misc/altitude.html here's an example of what I'm talking about. My local track is KCIR, it's altitude is 800ft. Say my stock time is 15.00 @ 89.0mph the weather that day was: 72 degrees, pressure 30.5, dew point 35 degrees. into the calculator that yeilds a DA of 1230 FT. Using the chart and multiplying your time and mph that yeilds: 14.881 @ 90.15 that's my corrected time to a DA of zero. now next time I go out with my new mod I can correct that new time to a DA of zero and actually see what gain I got. Using the DA calculator I have a link for you can see the relative horsepower gained from great weather conditions. If you have a track close to sea level with great weater you can get -2000 or better DA's and get about a 10% HP gain just from the weater, which obviously makes a HUGE difference in times. Link to comment Share on other sites More sharing options...
383ss Posted January 27, 2004 Author Report Share Posted January 27, 2004 here's something interesting too, just to show you how much of a difference it makes. If I were to race today at KCIR in Kansas City with the weather of 10degrees, 30.23pressure and 3 degree dew point at 800 feet, the DA would be -2750ft. if I ran 15.00 @ 89 stock at 1000DA which is probably close to accurate, I would have run a 14.32 @ 93.26 in today's weather. STOCK this is how a LOT of the big guys over on ls1tech.com get such great numbers with their cars. down in TX and FL and the northeast in the winter and spring, weather is GREAT for racing. -2000 DA's are pretty common. here in KC we're stuck with 0 being a great day. Link to comment Share on other sites More sharing options...
383ss Posted January 29, 2004 Author Report Share Posted January 29, 2004 did I just go over some peoples heads??? I thought there would be a few comments.... or maybe you just don't care If there are any questions ask!! I know it can be a little confusing. Link to comment Share on other sites More sharing options...
BenKey Posted January 30, 2004 Report Share Posted January 30, 2004 Nope, great links, thanks. Link to comment Share on other sites More sharing options...
bdaly Posted February 3, 2004 Report Share Posted February 3, 2004 I actually used some of this information to end a conversation with some Mustang guys, thanks for the links. Brian Link to comment Share on other sites More sharing options...
Viperkiller97 Posted February 3, 2004 Report Share Posted February 3, 2004 Sweet Link to comment Share on other sites More sharing options...
Dale-01L Posted February 10, 2004 Report Share Posted February 10, 2004 Hey guys - Instead of going to multiple websites to calculate the difference, theres a website that does it all for you here: http://www.modulardepot.com/density.php Works pretty well.. -Dale ------------------ 2001 Silver L 1.64 - 10.83 @ 127.57 Bone Stock! Link to comment Share on other sites More sharing options...
adams2003 Posted February 10, 2004 Report Share Posted February 10, 2004 I just did the calculations and my 13.244 @ 101 run came to be 12.97 @ 103.12 wtih the corrections. I still want a time slip though that says I ran a 12 sec 1/4. Link to comment Share on other sites More sharing options...
Dale-01L Posted February 10, 2004 Report Share Posted February 10, 2004 If you went 13.2 @ 101 at Fontana, I would say you have a pretty good chance of running a 12.9x at either Carlsbad or Famoso... Fontana is a couple mph and a few tenths slower than Carlsbad on any given day because of the altitude / temp... At least from what Ive seen of other peoples times, that is... -Dale Link to comment Share on other sites More sharing options...
Duner Posted February 19, 2004 Report Share Posted February 19, 2004 While I really like the numbers from the modulardepot site, I don't think it's very realistic. On the run in this video http://krcperformance.com/images/DunervsLethal.wmv The conditions were: 103 degrees 24% humidity 3075' altitude pressure of 29.81 ET of 12.31 speed of 114.49 According to the modulardepot site that would correct out to an 11.12 @ 125.85 mph. I'm having a little trouble believing that..... as much as I would like to! I've been using a different calculator that does all that - plus give you corrected HP numbers. I think it's alot closer to being accurate, but not nearly as optimistic. Try this one: http://users.frii.com/morrisc/cars/tools/e.../elevation.html That give me a 11.48 @ 118.71 Link to comment Share on other sites More sharing options...
MustBBrent Posted February 19, 2004 Report Share Posted February 19, 2004 Cool, that makes my 14.96 at 91 into a 14.62 at 94.02 I knew the truck felt faster than they were giving me credit for. I mean, I was leaning into the steering wheel, grittin my teeth, and everything. Link to comment Share on other sites More sharing options...
chiel Posted March 14, 2004 Report Share Posted March 14, 2004 I have to wait till 18 june to make a 1/4 mile run, i know what i run 1/8 mile 9.479 at 120.60 km/h. Can you calculate what i run at 1/4 mile? Link to comment Share on other sites More sharing options...
evandostert Posted July 18, 2004 Report Share Posted July 18, 2004 Great link. Now I know why I was off on my numbers. Link to comment Share on other sites More sharing options...
383ss Posted March 4, 2005 Author Report Share Posted March 4, 2005 ttt for racing season. Link to comment Share on other sites More sharing options...
383ss Posted March 4, 2005 Author Report Share Posted March 4, 2005 I have to wait till 18 june to make a 1/4 mile run, i know what i run 1/8 mile 9.479 at 120.60 km/h. Can you calculate what i run at 1/4 mile? <{POST_SNAPBACK}> better late than never, right? 1/8 Mile ET = (¼ Mile ET * .655) - .22 1/8 MPH = 1/4 mile MPH / 1.27 approx. Link to comment Share on other sites More sharing options...
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