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-   -   Drag racing in the heat/humidity (http://www.wrxtuners.com/forums/f113/drag-racing-heat-humidity-23810/)

zmanoside 07-24-2008 09:27 PM

Drag racing in the heat/humidity
 
So I went to the track 2 weeks ago, 05 STi stg1 and pulled a couple 13.2's. Weather was mid 80's. Tonight, stg 2 I couldn't pull better than a 13.4!!! I knew it was damn humid tonight, so I checked the weather online when I got home and at the time I was running it was 92 degrees with 94% humidity:eek: It seemed like my car was def not running great/ slower. So what is worse, the heat or the humidity??? And how exactly do these factors effect HP and 1/4 mile times? I know the colder the air the better, but how does humidity affect the times??

Z

mosc 07-25-2008 05:40 PM

humidity reduces the density of air similar to altitude or temperature. However, it's not very linear. The hotter it is, the more water is required to reach a given "percent humidity". Having 94% humidity when it's 50 degrees outside is not really that significant but as it gets hotter (say, the 90s), it becomes more and more significant. So, humidity is bad on a hot day. Really bad on a really hot day.

zmanoside 07-25-2008 10:19 PM

Yeah it sucked pretty bad. I started doing some research myself on the web on drag racing and weather conditions, I found that the barometric pressure has the most effect on racing, followed by temp and then huidity. Hard core bracket racers actually buy "weather stations" small electronic devices that mesure all of these factors and more to determine what their car will run on a specific day in specific weather. I was just realy pissed that my car ran that slow. I'm def waiting till it gets cold out to run my car again. It's just pointless to tryand get into the 12's when its this damn hot and humid out.

Z

03 CrazyTaxi 08-02-2008 04:03 PM

Yeah humidity and heat FTL. Last night I ran at our Midnight Madness. Wasn't able to check temp or humidity but it was unbelievably hot and humid. At stage 2 on my bugeye, I ran 13.7 earlier this year. After my turbo swap, I should have been running faster. However I could only pull a 14.5. Car was running fine, just couldn't pull off anything better.

BC_Girl 08-03-2008 09:59 AM

[QUOTE=zmanoside;201464]Yeah it sucked pretty bad. I started doing some research myself on the web on drag racing and weather conditions, I found that the barometric pressure has the most effect on racing, followed by temp and then huidity. Hard core bracket racers actually buy "weather stations" small electronic devices that mesure all of these factors and more to determine what their car will run on a specific day in specific weather. I was just realy pissed that my car ran that slow. I'm def waiting till it gets cold out to run my car again. It's just pointless to tryand get into the 12's when its this damn hot and humid out.

Z[/QUOTE]

Now I'm curious. The barometric pressure is the number one weather condition that affects the way our cars run? What did you find? Is it better if it's high or low?

03 CrazyTaxi 09-02-2008 10:02 PM

Yeah, so I figured it was just the heat and humidity last time... Nope, went to the track this past friday and couldn't run better than 14.4. My tuner tells me my boost is the problem. It's oscillating to the point that it is basically ineffective.

Labukas19 09-10-2008 06:59 AM

[QUOTE=03 CrazyTaxi;203985]Yeah, so I figured it was just the heat and humidity last time... Nope, went to the track this past friday and couldn't run better than 14.4. My tuner tells me my boost is the problem. It's oscillating to the point that it is basically ineffective.[/QUOTE]

well you did .1 better :sneaky: lol

SuBeast 09-10-2008 11:54 AM

^lol... Any improvement is better than none. But my Jetta runs 14.0's maybe 13.9's at it's best... WtF? Definately something up...

You think 90 degrees is heat? WTF! I live in 100 degree weather daily lol! I think a few weeks ago it hit 110+... Yeah, my car didn't really like that. (omega intake manifold heat-soak.) It's actually cooled down to 89 today and holy moly it's cold! It's supposed to get back into the normal triple digits this weekend though. I need to wait for a cooler day to head back up to the track for some more time's.... Maybe in like October or November it'll get better.

zmanoside 09-10-2008 02:56 PM

[QUOTE=SuBeast;204500]^lol... Any improvement is better than none. But my Jetta runs 14.0's maybe 13.9's at it's best... WtF? Definately something up...

You think 90 degrees is heat? WTF! I live in 100 degree weather daily lol! I think a few weeks ago it hit 110+... Yeah, my car didn't really like that. (omega intake manifold heat-soak.) It's actually cooled down to 89 today and holy moly it's cold! It's supposed to get back into the normal triple digits this weekend though. I need to wait for a cooler day to head back up to the track for some more time's.... Maybe in like October or November it'll get better.[/QUOTE]


You are in cali though...DRY HEAT...come to NC on a hot HUMID day in 100 degree heat with 95% humidity...as letterman says, its the "feels like" temp..ya, feels like 110-115 with the humidity out here..nasty mugginess

BugEyedAWD 09-10-2008 03:12 PM

^ or just go to texas and they will tell you its just plain NOT SAFE to go outside.


but i live at the base of the smokey mountains so if i have heat issues, i just climb altitude. LOL (joke)

but yeah, i dont know what it is, but around here, the temp has sucked. I only pray for winter. the car will run alot better. I notice i use a little bit less fuel when its cooler out too.

:EDIT: ^ if i stay out of boost of course.

SuBeast 09-10-2008 06:03 PM

It gets humid here too sometimes. It just probably rarer than over where you are. It was pretty humid a couple weeks ago, not sure of the number reading, and it lasted a couple days. But I know waht you mean.

headstart101 09-16-2008 11:07 PM

[QUOTE=SuBeast;204550]It gets humid here too sometimes. It just probably rarer than over where you are. It was pretty humid a couple weeks ago, not sure of the number reading, and it lasted a couple days. But I know waht you mean.[/QUOTE]

I live about 25 minutes away from you, and it gets hot but not humid, mostly dry air. I work on a flight line that would hit about 140 degrees plus at certain times of the day, im talking about the point where your hands are burning literally and your eyes are watering but I guess not everyone here works with FA18 hornets daily. But i cant complain because every year they bring supers cars and bikes to the base to run them on the runway, sometimes against our FA18's , this yea they had bikes like the busa and stuff, but a few years ago they had the bughatti and the hennessee viper and some 911's and a few other million dollar cars, cant wait to see what they bring out next year.


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