How much is good air worth?
 

Happy Thanksgiving everyone!

Loaded up this morning to head to the 3-day Thanksgiving race in Dallas.

http://i1248.photobucket.com/albums/...giving2013.jpg

It was a blustery 28 degrees in East Texas this morning! The last time out we ran a PB of 11.74 (1.53 60') with a DA of 1850'. This morning the DA was NEGATIVE 1800'. It's supposed to stay well below sea level the next several days. Assuming they prep the track correctly and that it hooks how much ET is there in a swing of 3600'?

Hope each of you have a safe and peaceful Thanksgiving Day with your friends and family.

Scott

Re: How much is good air worth?
 

It will be fast, however you will run into the "law of diminishing returns" where the car simply can't go any faster, regardless of DA. My quickest ETs are at -400 DA when the Baro was 30.20. I ran in -1200 DA and the car was no quicker.

Make sure you give it plenty of fuel....

Re: How much is good air worth?
 

you shall see

Re: How much is good air worth?
 

From my experience, our cars would probably pick up .15-.20 in those conditions, but as Don said you can get to a point when the air is so good it doesn't make much difference. Every car is different, you just have to learn how your car is effected, which you should today.

Re: How much is good air worth?
 

+1800 to - 1800. 2 tenths. Give it some fuel. Take away some timing. Both.

Re: How much is good air worth?
 

My car runs better at lower DA.
But you have to add in Moisture content that takes away the Oxygen if you have equals DA readings.
Cold dry days are best with high Barometric readings and very low humidity.

Learned a lot from flying planes. Especially in Denver on hot days.
Fully loaded private prop planes without a TC cannot take off.
Prop can't generate enough bite and the wing enough lift.
DA readings can be several thousand feet higher.
Barometer readings in the 26 range.

Coastal tracks you can see better DA than middle America.
Strange that Cecil County Dragway is 500 ft above sea level.
But Cold Air Day Drag days see DA's as low as 2000ft below sea level.

East coaster love to go to that track for bragging rights.
Racers from Ohio take the treck out every year just for that experience.

My best on Cool airs are consistent Low low 13's.
Managed a 12.88 at Cecil. DA -800ft
Where at Pittsburgh last Summer ran 13.80's hot lapping, in the morning a 13.65 cold.
DA was reported near 4000ft.

D

Re: How much is good air worth?
 

Cecil is not the best example in my opinion because I believe it is downhill some.

Jeff's estimate is solid

Re: How much is good air worth?
 

Thanks guys. We will post results after the Super Pro cars get some rubber down and the starting line is good. I appreciate the advice ... can't add fuel though as we don't have the ability to tune. Not even sure if that is legal in Pure Stock. ??? We have a really good tuner that does ours on the dyno but once you leave him no adjustments. Lows 11.5x would be nice ... almost a second under in a car with OEM heads that we still drive on the street.

Scott

Re: How much is good air worth?
 

http://www.dragtimes.com/da-density-...e=Calculate+DA ....This is a link to a site that helps with calculations ---Trevor

Re: How much is good air worth?
 

Dave just providing my experience.
BTW made a mistake, Cecil is 320 ft. above sea level.
Mason Dixon is 550 ft. above sea level.
The difference is only 3ft and within margin of most tracks.

ATCO and Englishtown are 55ft and 57 Ft above sea level.
Have run comparable best times at cold weather meets.
Englishtown's cold air day winds freezes up the starting line as soon as Sun drops a little.
Ruining making a good run.

Cecil is an easy track to get to.
Sun falls behind the starting line keeping it warmer longer.
Seems to get better air more often than other tracks.
The air feels calmer and more tail wind.

Need to check on this.
Cecil's location may have better weather patterns and terrain.

Englishtown is a consistent Headwind Track.
Can tell watching the planes take off & land at the local airport next door.
Historically most of the records were set at Atco and Etown in April.

Early records from 1975 show consistent one 1-2 tenths better at Cecil compared to Mason Dixon, 75&80, York (at the time), Capitol.

Sure would like to know what other racers records show.
I know Tom Gould kept some serious records.

Dan

Re: How much is good air worth?
 

At times you get DA readings that look awesome but the ET's aren't what your predictions tell you. This usually caused by a cool temp reading but baro. and humidity aren't that great, happens at Maple Grove and Atco frequently.

Re: How much is good air worth?
 

At the Gator's this spring. The temps were in the low 70's but the humidity and barometer were killer. So it was a mineshaft.

Re: How much is good air worth?
 

My old Tag weather station does not give enough weight to humidity. It always predicts too fast in humid conditions. If I wasn't done I would find something better.

Re: How much is good air worth?
 

You're not done, you just think you are

Re: How much is good air worth?
 

I'm wondering if D/A is simply not D/A and comparing isn't as accurate as I once thought.

Tested at MIR on Oct 20th.

1.136 60'
3.227 330'
5.011 660'
137.22 mph

58.6 deg
57% humidity
29.82 barometer
354' D/A
42.50 grains

Now at a race at Cecil on Nov 2nd

1.136 60'
3.221 330'
5.002 660'
137.25 mph

57.4 deg
55% humidity
29.29 barometer
851' D/A
39.14 grains

The very next run at Cecil the car set the class record for an N/A car of 4.988.

I sit here comparing weather and at Cecil the barometer was way lower and higher D/A but the car still ran quicker. Scratching my head over this as when I looked at the weather station every run I expected the car to run slower than it had at MIR based on the air.

And I never did get to run in what I feel is mineshaft air this fall. Probably a good thing as I got hit with 50 lbs for running what it did. lol

Re: How much is good air worth?
 

Well, turns out the race is 1/8 mile. Did not know that. My wife Wendy is learning to drive the car and did well today only having 5 passes in her life under her belt. Broke out first round and lost after a 0.519 light.

After she lost I jumped in the car for some 1/4 mile TNT. New PB on everything: 1.50 60', 7.29 1/8 and 11.58 1/4. No mph on the ET slip. ??? DA according to my phone was -100'. Haven't checked Drag Race Times' web site yet.

Sun starting to set and going to get cold but we are going to try to get some more runs tonight if the starting line doesn't go away.

Scott

Re: How much is good air worth?
 

Scott,

I think Jeff,Jimmy Jr. & Dave were right on two tenths .. As you know there are many other factors that enter in this discussion .. But, their est. was right on, no sub for experience ... Good Luck testing & write it all down !!

Re: How much is good air worth?
 

Yep, they were right on it! Here we are on Friday ...

http://i1248.photobucket.com/albums/...giving2013.jpg
After our last TNT pass Friday night the Check Engine Light came on and the codes indicated the oxygen sensors had gone out. We packed it up and came home and will replace those this week.

Scott

Re: How much is good air worth?
 

Any good tuner cam make the O2 sensors have no effect on WOT performance. Or, you could have just unplugged them to finish the weekend.

Re: How much is good air worth?
 

Or gone to the auto parts and just changed em. It's not that hard

Re: How much is good air worth?
 

Look into getting a speed density tune like Ed said. Hands down the best setup for racing applications. No reason to even have the O2's on board IMO.

I would kill to run in air like that.

Good run!

Re: How much is good air worth?
 

Doesn't speed density mean closed loop? Then it would need the sensors.
Alfa N is open loop ( I think ) Sensors are just for data logging.

Re: How much is good air worth?
 

MAF sensor mode, Speed Density, and AlphaN can all be open or closed loop. With a Pure Stocker, I would certainly leave the MAF on it. I don't think it would be legal to remove it, would it. At least the original Pure Stock rules would not allow it. This new "pure stock " ain't really purely stock. May be legal now? I don't know.
Anyway, if you know how, you can stop long term fuel trims from effecting WOT fueling.

Do you guys run open headers? You most certainly don't want closed loop, with a factory computer, with open headers.

Re: How much is good air worth?
 

Thanks guys for your comments.

No Ed ... open headers are illegal. We can run the OEM exhaust manifolds open with no mufflers but if you run headers you must run mufflers. We run 1 & 7/8" American Racing Headers, an off-road X-pipe with no cats, and GM C5 Z06 titanium cat-back mufflers.

As far as the MAF I believe that has to be present as well. When you guys talk about open and closed loop, etc. I'm not sure what you're talking about. We get our tunes from Stephen Covington in Longview, Texas at East Texas Muscle Cars. He seems very knowledgable and takes him time tuning the car on the dyno and on the street when we go. The times and consistency that the car runs have been pleasing to us.

So just buy two new ones and replace them?

Scott

Re: How much is good air worth?
 

Leaded fuel is hard on them. If you run race gas just have him put in in open loop, and shut off the codes. If you use unleaded fuel, I would wonder why they failed. They typically last over 100,000 miles.

Re: How much is good air worth?
 

Open/closed loop is referring to whether or not corrections are being made in real time. If you run in closed loop, corrections based on O2 sensors, air temp, water temp, MAP sensor, etc. will be applied. These corrections are normally programmed in the ECU.

If you run open loop, you will just get the same amount of fuel no matter what the conditions are (except for maybe some factory programmed corrections).

Re: How much is good air worth?
 

He runs a factory computer which does not make WOT air/fuel corrections unless something makes it "think" it is lean at idle & part throttle. If it sees (or "thinks" it sees lean conditions causing positive fuel trims it will, after a short time, add the same percentage of fuel at WOT it was adding at part throttle. That will, of course , cause over rich conditions racing. If he can run quicker after resetting the computer he has that problem. If so, he can pm me and I will tell him a simple way to cure it with a small jumper. :-)
A quick way to reset it's memory also.

Re: How much is good air worth?
 

We don't run leaded racing gas; only unleaded fuel. I've always used 93 octane from the gas station but the last time we were at the track (before this race) we put 5 gallons of a higher octane unleaded gas that the track was selling. I'm wondering if they gave me leaded fuel accidently.

Re: How much is good air worth?
 

It would take longer than a day for lead to hurt the O2s.

Re: How much is good air worth?
 

I used a wide band o2 system with my data logger for 3 or 4 seasons. Removed it and sold it to a friend, still being used today with the same sensor and lead racing fuel the entire time.

Re: How much is good air worth?
 

I replace mine each season just to be safe. Street cars get a lot more run time than a race car. It will cause O2 issues in a daily driver.

Re: How much is good air worth?
 

Gets back to what I said, I think you are going DOWNHILL at Cecil, just like 4 wide/concord, simply put, the startingline elevation is higher that the finishline elevation

Re: How much is good air worth?
 

Any of the Coastal good air tracks are at least
3/10 quicker than brainerd!!! Lololol

Re: How much is good air worth?
 

Todd:
Cecil usually has a mild tail wind.
Did you check wind direction?

Ed:
Regarding O2 Sensors..
For some reason the Left Failed.
Replaced both and saved the good one.

The SS uses 93 Octane.
Couple racers prefer Shell over Sunoco.
Need to know more..why?

At Mason Dixon Dragway can get 100 Octane Sunoco.
When the car is right the 100 Octane is not needed.

Wondering if tuning to 100 octane would be helpful?

Ed:
What do you think about running 100% gasoline vs the Street Fuel?
D

Re: How much is good air worth?
 

[QUOTE=Dan Fahey;410938]Todd:
Cecil usually has a mild tail wind.
Did you check wind direction?

Ed:
>Regarding O2 Sensors..
>For some reason the Left Failed.
>Replaced both and saved the good one.

>The SS uses 93 Octane.
>Couple racers prefer Shell over Sunoco.
>Need to know more..why?

Probably not grounded in fact. Unless both have a refinery close by, they both come from the same place. We have two local, one Sunoco, other is Holley. All fuel around here comes from one or the other. I have customers from both places. They tell me everybodie's of a given octane comes out of the same storage tanks.


>At Mason Dixon Dragway can get 100 Octane Sunoco.
>When the car is right the 100 Octane is not needed.

>Wondering if tuning to 100 octane would be helpful?

Might like a degree or two more timing. Just have to test that.

>Ed:
>What do you think about running 100% gasoline vs the Street Fuel?

D [QUOTE]

We have.100% pump gas around here. Stations offering that get a few cents per gallon more. I don't run that E-anything unless I just can't find anything else. The difference in mileage almost pays the difference, and I don't like running that crap through my stuff that crap is only a good deal for the corn farmers. If you have to burn more of it to go the same distance, I don't see the big advantage. I think EPA is about to learn that also. About 2 MPG difference in my wife's Lexus.

Re: How much is good air worth?
 

Humidity however slight in change is a factor