well to answer your question about the da. my best time was run when it was 40* out side with vertually no humidity in mid Feb,

last night the temps where in the upper 70's to lower 80's. and the humidity was way up.
not very motor friendly.

I dont have one of those barameters that will tell you the D/A and all, but the cutouts are the only mod I have done since the 14.65 run I made in feb.
in march I ran 14.7 at the springbreak shootout( no cutouts), and the weather was about the same yesterday as it was at the shootout.


2-1/2 dual cutouts
my mph went up about 2 mph
no I did not make anypasses with them capped. I think the trucks donot respond well to mods untill they have been driven for a while with that mod.
so to capp them I would have had to go drive it for a while and I didnt want to do that.


no Mac I have 3.73's

 

See IMO you cant track progress like that. You need to find the DA for each of those runs.

All you need to do is have the time of each run then go to weather underground.com and find the exact weather values.

 

well I have time slips from every run made.


just out of curiosity the temp would have nothing to do with it?
I had always thought that the cooler the weather and the less humidity the quicker the vehicle would be.
I have always run slower when the temps are above 75* never have got it to run quicker unless the temps where down.

 

this is the first time I have really started looking for the d/a, I had heard some guys talk about it but didnt understand what I was looking for.
so how do you explain the tenth off of my times.

 

cooler the temp and the less the % of humidity - the more power it will make.
- - reasons for ice and intercoolers..

 

and this is my reasoning for stating that the cutouts dropped me a tenth of a sec. Im not argueing with any one here, just stating that the humidity was up, as well as the temps, and the only mod I have done was the 2 cutouts.
oh and put a 2/4 drop on it.

 

Ok, in a nutshell here is DA.

DA stands for density altitude. The temp, dew facotr and barometric pressure can all effect the density of the air IE. how much oxygen is present in a specific voulme of air. The lower them temps, dew factor and higher pressure all make for better HP. You know how running at higher altitudes lowers your HP because air is less dense up thre. Well the weather can effect the "effective" alititude you are running in. On cold, dry days you will run like you would had you been in a lower altitude, yet on hot humid days you might as well be running in Denver, Co.

The DA can change quite a bit throughout the night and day so you it is very easy to see 2-10ths difference and as much as 2mph or more depending on your mods with just the change of DA. For instance in one evening I have seen the DA go from 1500' to -100'. My track is only 50' above sea level but in the summer when it's 105deg out the DA will make it like you were racing at 2500' above sea level.

Sooo to track your times you need your timeslips with Dates and clock times. The you can go here Weather Underground . With some searching you'll figure out how to use this to find a location closest to your track and enter specific dates and it will tell you the weather for that day, throughout the day and night so you can match it up to your times on your timeslip.

Once you have the

Altitude of your track
Temp
Altimeter in Hg
Dew Point in Deg. F

You can go to this site http://wahiduddin.net/calc/calc_da.htm and enter those #s and get the effective DA for those runs.

This is the only way to accurately trck something like this. Without these #s you are only guessing and defiantely not scientific. It's fun too

 

I GOT IT !!!
the 2/4 made you faster due to less wind resistence and turbulence from the underside of the truck...

 

wuuuhahahahaha.
yeah thats it why didnt I think of that

thanks f8lpony I will try and find my slip with the 14.65 and compare it with the 14.51 to see .

 

NP man, this way you can either prove or disprove the cutout theory and back it up with real evidence