Corrected for sea level / Bull?

[88workcar]

I always bothers me to see this in the mags, here, ect... I just don't believe it. Why is it that if you watch NHRA, no matter where they are, the cars always run VERY close to what they ran at a totaly differant track, cross the country, in the mountains, in the vally, ect...

To me this is like a ricer saying, Yea it runs 12s, but....and it is a 15 sec car. I mean really, if a dyno shows 400hp in NY, bing the car to La. and it will show 452hp? I don't buy it.

Help me understand or is this really just bull.

[Murdock]

At each NHRA track the ET is automatically corrected for each run. The timing computer takes the correction factor into account when it displays the ET on the board. So if your watching on TV or at the race you would never see it, but it is there.

Murdock

[5ohCOUPE]

uuuhhhh

[WADS56]

Not to mention a top fuel car and it's nitro mix will change from track to track, and barometric(sp) pressure. They can get more agressive with the fuel in a more elevateed area.

[red82gt]

Street cars are affected a lot more than faster cars as well. The two track I run at are one at sea level and one at 1700ft. I've ran 104mph at the sea level track and 99 mph on a really hot weekend (100*F) and dry as a wick (4000ft corrected altitude). So altitude does affect a street car a lot.

No it's not bull. Haven't you ever been skiing up in the mountains where you climb at least 2000'-6000'ft. during the drive up the hill? The car/truck you are driving will feel SOOO much slower. Way down on power. My foreman is getting ready to move to Colorado. I forgot which city, but it's up at like 8 or 9000'. They already bought the house up there and his wife has made the move. His wife's Honda SUV felt so much slower that she thought something was wrong with it! She was almost thinking about taking it into a shop. Haven't you ever seen guys from Colorado post their times from a track that is at 4000' or 5000'? There times are always real slow compared to times others turn with similar mods down at 1000' or lower track. I run my Mustang at a track that is at 2700' above sea level. I've also ran my car at a track that is no longer around (Terminal Island, Brotherhood Raceway) that was right at sea level, basically on a man made island just several feet above the ocean water. I never made it there with my new motor. But on my stock motor with all of the normal bolt ons & 3.55 gears I was turning 14.2s on street radials. Same setup at the track in the high desert (2700') netted me several 14.7s. So yes, there is a difference.

Here is a link to the website of the track I race at. Scroll down towards the bottom and you'll see their formula for the correction. http://lacr.net/indexmain.htm

[88workcar]

I bow my head, turn my backside, and allow the trashes to start.
owch
oooh
ouchhh
stopp
stopp
arrgg
owww
it hurts
stop please

I love you guys, thanks for the info. In my sig it says young and stupid, I must have leaned over to the stupid side. I'll be OK for a while.

[gtsr515]

In my opinion the reason sea level effects our cars so much, but NOT the NHRA guy's is the NHRA guy's have a BILLION horsepower, they can run what they want, where they want, for Top Fuel cars, the BIGGEST concern no matter where they go is how the CLUTCH is set-up, sometimes you'll hear them say.."We're gonna turn her up a notch.....well, it's not the motor that gets turned up.....it's the clutch.........

Am I way off???

The local track I used to race at (Byron, Illinois), Heck!...that track was downhill big time...I mean obviously, and NO MATTER WHAT, I always ran quicker at Great Lakes Dragway (Wisconsin) and that track is straight as a string???????????

HHHHHmmmmmmmmmmm.......great topic 88 workcar!!!!!!!!!!!

Jay

[Technick]

The other thing that Top Fuel cars can do is spin the supercharger faster to make up for the difference of the thin air. The Pro Stock guy's run 1/2 sec slower at Denver than they do anywhere else, because they are naturally asperated (no power adder) Now you can take your 7,000 foot e.t. and correct for altitude and you will have an idea of how fast your car WOULD/SHOULD run at sea level!

[Dark_5.0]

Elevation makes a huge difference Odessa is 3000ft above sea level. I know people that have ran ther car at a sea level track after running here and ran 5 tenths faster.

Over here.

Ls-1's almost never hit 13's stock
99+ GT's run mid 14's at best
96-97 GT's often run in the 16's

I envy you people that get to race at sea level.

[red82gt]

The first time I raced at altitude I thought the track was too short because my 3-4 shift didn't come until about 20 ft from the finish line! My 3-4 shift at sea level was at about the 1000ft mark. My friends 99GT didn't even have to get out of 3rd at the top end.

[drtbiker]

yeah tell me about byron, how can u even race there, funny story is my buddy lost 3 tenths with his focus when he raced there vs greatlakes.... he ran like 15.30+@ greatlakes and 15 flat at byron


sorry about that it is a little off the topic but what the h*ll how can that be far to even say u ran a time when u didnt

later

[Shaggy]

My expierence is Yes elevation can effect et big time but on the flip side using the conversion formula to correct it to sea level is about as accurate as calculating you ET and MPH off of your 1/8 mile time. It will give you a general idea of what you would run but it is not a truely exact science because all acrs respond a little different to the elevation just like not all cars accelerate the same between the first 1/8 to the second 1/8.. a good example is my falcon it runs a 13.29 1/4 @ 100.00 but if you take my 1/8 8.43 @ 82.34 I should have run a 13.15 @ 103 according to the analyzer here(which is closer then when i do the math on the street because i just use the old stand by of multiplying it by 1.5 in my head). I wish my car could MPH 103 the best if has ever done is 100.15 and it has only broke 3 digits about 4 times the rest of the time it is a solid 99 MPH car. Anyway back to the point It is close but not perfect.

[dragstang86]

Like mentioned above...a street car is going to be affected more than a higher hp car. For example a high compression engine isnt affected as much by weather changes as a lower compression engine. A low compression engine may run 4-5 tenths faster on a cool november day than a hot summer day where a high compression engine may only run 2 tenths faster in november than it did in july.