[ULTRAZLS1]

I've always thought rule thumb every 1000 DA drop was good for about .1 on your average NA car.

[JFM-jr]

Originally Posted by ULTRAZLS1

I've always thought rule thumb every 1000 DA drop was good for about .1 on your average NA car.

Originally Posted by BadBowtieProductions

2000 DA - 12.20 (a week after I bought it)
1300 DA - 12.12
1200 DA - 12.13
500 DA - 12.07
-100 DA - 12.04
-300 DA - 11.99 (tires beyond the wearbars)

I have went by the rule of thumb a tenth for every 1K feet as well and the number above show it is close. 2,300 feet = .21 in ET

as for how Prays car would run in +2000DA id like to know as well. The temperature would be warm outside for those kind of DA's and the benefits of E85 would be better over pump gas in the warmer weather.

[PRAY]

If we are going to apply DA to my runs then we need to apply it to all the runs on the list. I have always suggested correcting numbers to 0 DA for comparison sake. Everyone cries about SAE dyno numbers but no one with "fast" cars want to compare corrected drag times. Strange.

If we are going to take the DA thing as gospel then we need to dispel the rest of things I posted about as known factors to going faster. So every .1 in 60ft isn't .2 at the stripe. 100lbs off the car isn't worth .1. Rotating mass on the rear wheels doesn't matter. 10rwhp isn't worth a .1 either. See where I am going with this. It seems to me that it is all hopes and dreams to bench race with. All that really matters is what it ran at the time in those conditions.

[Padre]

Originally Posted by PRAY

If we are going to apply DA to my runs then we need to apply it to all the runs on the list. I have always suggested correcting numbers to 0 DA for comparison sake. Everyone cries about SAE dyno numbers but no one with "fast" cars want to compare corrected drag times. Strange.

I don't know if anyone is advocating that. I certainly am not. Like a dyno, knowing DA is a tool. Knowledge is good. But the timeslip is the only thing that determines "records".

On the Gen5 list, it was good to know DA, not so that we could reorder the list, but so that we could understand all the factors in a run. The real drag racers could use that information to make their cars faster, while the unsophisticated bragged about numbers only.

I was in the Top 5 on three lists: bolt-ons, internal mods, and power adder, but I was racing at an old track in Alabama. I admit I was tempted to make a trip to ETown to get my hero run. But ultimately, when I did real races like the LSX Shootouts, the only thing that mattered was the WIN in my column on the timeslip.

Don't sweat any criticism. Like I said, knowledge is "power".

Padre

[Snowblind]

It would be nice to see you not make any changes and head back in different weather (as was mentioned earlier).

The main consensus here is that you gain or lose a tenth* for every 1000 DA swing on pump gas, PRAY is really the first guy that has posted detailed passes in mineshaft air, but the real question here is...how does DA effect the e85 car ? That's the results I'd like to see.

No one is knocking your run that I see, just curious what the correction factor would be running on corn.

* my personal results have shown tenth for every .5-.7 swing and I attribute that to the 11.5:1 compression imo.

[Fraxum]

Originally Posted by PRAY

If we are going to apply DA to my runs then we need to apply it to all the runs on the list. I have always suggested correcting numbers to 0 DA for comparison sake. Everyone cries about SAE dyno numbers but no one with "fast" cars want to compare corrected drag times. Strange.

If we are going to take the DA thing as gospel then we need to dispel the rest of things I posted about as known factors to going faster. So every .1 in 60ft isn't .2 at the stripe. 100lbs off the car isn't worth .1. Rotating mass on the rear wheels doesn't matter. 10rwhp isn't worth a .1 either. See where I am going with this. It seems to me that it is all hopes and dreams to bench race with. All that really matters is what it ran at the time in those conditions.

+1 I think showing real and corrected times is much fairer to everyone. It is not fair for example for those us who happen live near a good air dragstrip versus those who don't.

I don't get the corrected resistance either among all the internet dyno racers out there. No disrespect, that is still fun. I am happy with my 429 RWHP stock at JRE. Don't I get some kind of Internet cred for that? LOL

Is that 60' gospel actually true? The other one is HP = MPH. Especailly when the tires spin at launch, how exactly does that give you a higher MPH?

[PRAY]

Sorry guys, I haven't articulated my self well. My point is that there are cars out there much faster than mine that won't get the credit or "list spots" because I happen to live at sea level and we have good air at certain times. I think a corrected DA needs to be added to all times posted positive or negative to level the playing field to see what a certain persons combo would do in your common DA. But it needs to be applied across the board to all of their passes to see where the started and where they have finished. There is no real way to compare two cars or combos except to run them on the same day on the same track or dyno.

Did I have really good air, yes. Did I make Hero runs, no. I could have pulled seats, ran the gas down, cooled the car, etc. I did what I normally do at the track to keep the testing as regulated as usual. I took mostly factory stuff and did the best I could with it.

I do plan on hitting the track next time it is open but I will most likely be on pump. E85 is not exactly easy for me to get. Not hard either but everything has to be timed correctly to make the hour drive there and back with as little gas as possible for the conversion. Then time that out to make it to the track, make passes and make it to the gas station with out having to much fuel or running out of fuel.

I am actually disappointed with my car after this weekend to tell the truth. With how fast it went in 0 DA on street tires I honestly in my heart thought I was going to go mid 10.80's or better at 101/125. I got those numbers adding up all the gains that are common racer wisdom. I guess things don't always work out like the science says they would. So now I have to go back and dissect what happened for me to not reach the times it should have ran. If the weather thing really is a fact then what the heck happened? Is the motor hurt, is the rear shot? We all know the E85 works. My logs show the power gains. I am scratching my head a little here.

[PRAY]

Originally Posted by Fraxum

+1 I think showing real and corrected times is much fairer to everyone. It is not fair for example for those us who happen live near a good air dragstrip versus those who don't.

I don't get the corrected resistance either among all the internet dyno racers out there. No disrespect, that is still fun. I am happy with my 429 RWHP stock at JRE. Don't I get some kind of Internet cred for that? LOL

Is that 60' gospel actually true? The other one is HP = MPH. Especailly when the tires spin at launch, how exactly does that give you a higher MPH?

Here is my take on wheel spin and MPH. If you have to lift off the throttle at any point during a run you are losing mph. Spin does not make you go any faster. However, if your car is under powered and you dead hook out of your power band then some wheel spin with a tire that will recover will make you go faster. Pro Stock cars are a perfect example. Wheel spin with recovery helps them go faster.

The other day was a perfect example for me. I cut six or seven 1.61 60fts in a row with all kinds of tuning changes that helped or hurt in various places at 18psi. I then raised my tire pressure to 22psi and got just a minor hint of spin right after the hit that helped me pull through the dead spot around 2,700 where the converter locks up. I went a 1.60 and then hit it a little harder the next pass and went a 1.57. I can only assume that if I would have kept this trend of upping the tire pressure my 60fts would have gone down to a point and then crapped the bed. Now the flip side of that is that I was getting some wheel spin on shifts now negating the 60ft. Damned if you do, damned if you don't. I lost a little mph on the passes that I got some wheel spin on shifts. Not much, but a little.

[Ian SS]

Would love to show corrected times for weather in the fast list. I ran 8.0 in the 1/8 mile with a 3800 DA

[HVR]

We can swing 4500 to 9500ft in one summer day at times here. There is no definitive calculator that works I have found. A weather station and recorded data is the only thing accurate for us.

[EFI Tuning]

For those of you with iPhones there is an app called Density Altitude+. It uses the barometer built in to the phone, GPS, and pulls the temp for your location. Takes less than 5 seconds to get the DA.

I've compared it to Drag Times and it is on the money.

Tim

[PRAY]

Originally Posted by HVR

We can swing 4500 to 9500ft in one summer day at times here. There is no definitive calculator that works I have found. A weather station and recorded data is the only thing accurate for us.

Dang, that's brutal. I was thinking about looking at some property near Bristol TN for retirement. But that track sits at 1,400ft. It was 37* when I left there this morning and it was still +197. Forget that. I will stay around the low lands where we get some - DA.

[ULTRAZLS1]

Originally Posted by EFI Tuning

For those of you with iPhones there is an app called Density Altitude+. It uses the barometer built in to the phone, GPS, and pulls the temp for your location. Takes less than 5 seconds to get the DA.

I've compared it to Drag Times and it is on the money.

Tim

I got a similar app called AutoDens. Pulls the DA from the nearest airport

[PRAY]

The Fayetteville Airport is about 500yards from the track. I think I still will verify everything with my Kestrel.