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Hustla Supreme
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Discussion Starter · #1 ·
I am curious because I know my car is going to run even faster the closer to Sea Level I can run. As is I have run my car 14.311 at over 1200ft above Sea Level. I had heard this equates to about 2 or 3 tenths of a second difference.

Am I correct in thinking that? If so then I am right there knocking on the door to a 13.99 pass with the current set up and the race header and ACT Chromoly flywheel are on the way. This should free up maybe 15 more whp or more and I'll be hitting my powerband much quicker - I'm borrowing drag radials from my friend next time I run.
 

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nice numbers

Hello you will be very happy with race header,and with the times your running should be no problem to hit in the 13's.I have to hit the track but it's to cold here in ny like 30's.I believe we have similar mods. Aem cold,hondata-4,race header,magnaflow,ES inserts.short shifter.I really want to time my car,I finally got to run someone the other night,first time with race header.civic with gsr swap and I killed him easy.He was like I beat rsx's but WTF your car is fast,and sounds so mean.I was impressed,you gonna love your header,get motor mount inserts or your engine is gonna smack around really bad.Are you going to upgrade your clutch while your there? I was looking at the new act by comptech.
 

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You need to do two things.

First, calculate your density altitude. This is a combination of altitude and weather conditions. You can find a calculator here:

http://wahiduddin.net/calc/calc_hp_dp.htm

You'll need to enter barometric pressure where it says "altimeter"

Once you've calculated your density altitude, then calculate the density altitude at the track you would like to run at. You'll have to just pull some weather conditions from a historical database.

Then go to this link:http://www.gnttype.org/techarea/misc/altitude.html

Now, if you find that say your density altitude is 1500 ft in Chandler and then 300 ft in Carlsbad, CA, how do you convert? Well, the simplest way to do it is look at the relative differentials. The difference between 1500 ft and 300 ft is about the same as 1200 ft and sea level. The difference between 300 ft and 600 ft is about the same as the difference between 1500 ft and 1200 ft. So, here's an example calc:

Conditions in Chandler:

52 F
29.1" barometer
22% humidity
1200 ft altitude
Corrected density altitude: 2031 ft

In Carlsbad

62 F
29.95
45%
300 ft
Corrected density altitude: 672 ft

So, we have a differential in density altitude of about 1350 ft. Going to the tables, we see interpolated correction factors (halfway between 1300 and 1400 ft) of 0.9854 (ET), 1.015 (mph). Multiplying these by your best slip gives us:

[email protected] mph

So, that's about what you would run if you drove out to Carlsbad, or maybe Bakersfield on a typical winter day. Assuming of course that I got the conditions for your run right. If your run was colder, or with a higher baro, then the correction would be smaller. A true sea level run would be even quicker, but it isn't easy to get to true sea level conditions at west coast tracks. If we see anything approaching 500 ft density altitude, we're very happy. OTOH, East Coast guys racing at Englishtown, Atco, Maple Grove and at the track in Maryland will occasionally see conditions with negative density altitudes! That's right, effectively they have air density below sea level. I've seen some records set at those tracks where DA was close to -1000 ft. That makes a huge difference. The key is that the tracks are within 50-100 ft of sea level, get nice cool temps and very high barometric pressures. We should be jealous.

SC
 

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Hustla Supreme
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Discussion Starter · #5 ·
Damn, I had no idea so much went into determining such.

I was fuzzy on the barometer the other night but the temps were about 55 degree with 70% relative humidity thanks to the system that came from the North pacific through Cali.

One thing is for sure, I had tractions issues being the first time racing with the new powerband and Firebird raceway is also very un-traction friendly for street cars.
 

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Hustla Supreme
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Discussion Starter · #6 ·
Thank You Church that was more than I expected to get out of this thread for sure. So typically the conditions would be about 2 tenths different between here and Carlsbad, I'm fine with that!

I would love to run in South FL on a cool night, but I am thinking that certain Northeastern tracks might have even better conditions.

We all know Phoenix is not a great place to set records when it comes to sport compact drag racing but I could be in Denver so I'll count my blessings.

Thanks again - I'll feel more of a sense of accomplishment if I can trip the lights at 13.xxx here at my home track.....
 

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Hustla Supreme
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Discussion Starter · #9 ·
Yeah either way I'd love to run at Sea Level.


SC: When did you move from the Chandler/Ahwautukee area to So Cal.?

I've been running at Firebird for about 5 years and it's adequate but it seems like they don't take care of the track well like at Speedworld. Sport Compact Only night is the worst night for traction.
 
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