damon_Z

Here were my baseline conditions and best runs:

date: 12/5/04
time: 10:49 AM
location: Atco Raceway
relative humidity: 32.1%
temperature: 64.7*F
barometer: 30.01 InHg
dew point: 36.5*F
car's mileage: 46,500
tires used: 30 psi in GSC's with 48,000 miles
burnout method: 1 second burnout, no smoke
launch method: from idle
modifications: all modifications in my signature below, but not including the subframe connectors and the Continental 245/50/VR16 ContiExtremeContacts
other notes: oil and oil filter change was performed less than 2,000 miles before the time noted above; air filter was clean

Best 1/4 mile ET: 13.407@103.98, 2.075 60'
Best 1/4 mile MPH: 13.585@104.82, 2.257 60'
---------------------------------------------
Here were my new conditions and best new runs:

date: 11/26/05
time: 12:15 PM
location: Atco Raceway
relative humidity: 28.8%
temperature: 46.9*F
barometer: 30.19 InHg
dew point: 14.0*F
car's mileage: 50,600
tires used: 30 psi in Continental ContiExtremeContact's with 7,500 miles
burnout method: 1 second burnout, no smoke
launch method: from idle
modifications: see signature below
other notes: oil and oil filter change was performed less than 2,000 miles before the time noted above; air filter was clean

Best 1/4 mile ET: 13.262@106.99, 2.130 60'
Best 1/4 mile MPH: 13.326@107.10, 2.205 60'

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For the new runs made above, the only modifications made to the car were the Spohn chrome moly subframe connectors and the Continental ContiExtremeContact's. The car's mileage had also increased by 4,100 miles since the baseline runs were made in December 2004. Runs were also made on November 5, 2005. However, the timeslips and weather information for that day have been lost. The runs made on 11/5/05 involved the car with the same new information noted above, but I remember my best 11/5/05 timeslip being only 13.49@104.51 MPH with a 2.1xx 60'--which was actually worse than my best baseline runs back in December 2004 (noted above). Therefore, I really can't say that my new best runs were because of my subframe connectors or because of the Continentals.

All weather information was obtained with a Speedtech Pocket Skymaster.

How could my ET and MPH improve dramatically with only the few changes noted above? Thanks in advance for the info.

Roarin_8

iTrader: (5)

Alot of conditions come into play but most likely you got better air as your mph would indicate. The subframes would also help the car to launch straighter than without them. Stall the car up next time to the tires' breaking point, then release the brake and add the gas. I bet your 60' will decrease with that method since you aren't shocking the drivetrain from launching at idle.

DadsZ28

iTrader: (1)

Hi Damon, any given night or day the weather factors can play a big difference. For example I was down there friday night going 13.00s with one lucky 12.97 pass and 12.90 to 12.95 passes all day sat. I thought the weather friday night (which was freezing cold) was better than sat. morning but I ran faster on sat. with my 60 fts. being similiar. I think in your case if you get those 60 ft.times down into the 2.00 even high 1.9s you would see a huge in improvement in your ets. By your mph your car is making the power and you would see 13.00s for sure. I'll probably be going down next week for t&t weather permitting and have some more fun. Hope to see you and some of the other board members down there. I enjoy watching other f bodies run and talking to people to learn more and more about our great ls1s.

damon_Z

Hey! Thanks for the reply. There was another member, SheaMus, at Atco this past Saturday. I didn't meet him, but he said that he actually cut a 1.9xx and high 12s on the same Saturday with the same exact tires (at 32 psi) that I was using and with no suspension mods. He launched at 1000-1200 RPMs with the A4. So, I want to go back badly and practice launching that way. I'll probably come back on the 10th. If I still don't get at least a 2.0 60' launching that way, then I'll do what you're doing and just use some Nitto 555 R's.

I'm still blown away by your car--a consistent 12 second car with only an aftermarket lid and air filter as mods. Who was your friend with the black SS? Does he post here?

DadsZ28

iTrader: (1)

Thanx Damon I know with a little practice launching you'll be running right with me. My buddy Mike is the guy who has the black SS his 6 spd. car is a handfull. He has run high 12s before but has some bugs to work out hopefully he will be running next week also. I think he reads the boards once in awhile but doesnt really post.

LS1LT1

iTrader: (16)

Atco from November to April =

JL ws-6

iTrader: (50)

That is normal.. that's why most people like to go there at this time of year, the air is so good and whatnot, that everyone and their brother run .2 to .4 faster there this time of year then anywhere they will run all sumer long... great way to run a "new best"... just wish people would add in the sig's that they ran those times in wintertime conditions at atco. You have no idea how many people I know that do that.. anyone that has been trying to break out of whatever it is that they were running all summer always go there... and run at least a 1/4 second faster. Congrats on the new best though.. now just back it up somewhere next summer.

damon_Z

After looking at all of the recent Atco-related posts and seeing your reply here in the Eastern section, I think I'll need at least 30 rwhp in mods to get the same trap speeds in summer weather. I don't think I'll ever run the car in summer weather, but I will partially disclose the weather conditions in my sig.

LS1LT1

iTrader: (16)

I don't feel that that is totally necessary...obviously air quality/track elevation/location play a big role in track times as do raceweights, but being asked to always clearly point either one out or worse yet having someone try to actually imply that the run doesn't really count based on either parameter is just plain goofy IMO.
No one tries to tell John Force or Kenny Bernstein that their record breaking passes don't count because they had better air than the last guy or raced at a well prepped track, correction factors or otherwise.

JL ws-6

iTrader: (50)

no need to discloe weather.. just put a location and date on it.. that says enough.

damon_Z

Well, I like it just the way it is now. Anybody can just click on the link to the timeslip and see the date and the location. The weather condition is still partially disclosed.

NHRATA01

iTrader: (10)

Man, if I ever have access to a tow vehicle and trailer, I gotta go to Atco in the winter.

JL ws-6

iTrader: (50)

I agree with that. I know 100% that I could lop a good .4 off the slip just by going there this time of year no problem from what I was doing at LVD in the middle of summer.

Of course.... that will happen anyway after this weekend's parts go on.. and another good .4 after the tranny goes in this spring.... cage here I come!

damon_Z

I definitely agree with you. A talented guy with an M6 who just ran a 110 MPH trap speed with only an aftermarket lid and air filter still ran a 110 MPH trap speed in winter weather or not. You can't take it away from him. But I think we should still try to please those who take that stuff personally. Nobody's perfect. Therefore, I'll disclose as much as I can even though my timeslips are nothing to rave about.

LS1LT1

iTrader: (16)

Well, nothing is 100% guaranteed until it actually happens/until the number is actually run but I do agree that if all goes as planned you would be quicker for sure.

ButchN

iTrader: (24)

Just curious, why the big secret on the weather conditions & disclosures?

JL ws-6

iTrader: (50)

Another 50 hp, about 100 lbs out of car, and car will have th400 with big n/a stall, and hal shocks on it by the next time it sees the track. I'm the first one to admit that I will never drive the car with a stick to it's best potential.. I'm a granny shifter. That being said, and the work that the car has gotten, and is getting during the off season should be more then enough to get me booted out after the first full pass I make for not having the cage in yet I'm positive of it.

Hell, the 60 foot gains from a transbrake launch with the TH400 and the hal's set properly vs. the best case 1.79 I have ever gotten with the 6 speed and stock shock setup alone would be a good .3 by the end of the track, all things ( track, weather, car weight, power ) being the same as it was the day the 1.79 was run.

but I agree.. show me, don't tell me.. until I have slip in hand, it is all hearsay. The dog would have caught the rabbit if it didn't stop to ****.

damon_Z

What secret? Do you think I should post all of the below in my sig?

date: 11/26/05
time: 12:15 PM
location: Atco Raceway
relative humidity: 28.8%
temperature: 46.9*F
barometer: 30.19 InHg
dew point: 14.0*F

I thought we had a limit on the number of characters for our signature. One guy implicitly suggested that I should disclose weather conditions. Later on, the same guy said that the date and location was good enough. Are you now suggesting that I show all of the above in my sig?

JL ws-6

iTrader: (50)

Nope, date and location is plenty..... everyone in the know can translate that.

Example.. if you ran XXX at XXX at atco in late november.. people that race understand what that means.

Or, ifyou ran XXX at at the track in denver in july, peopel also understand that is one of the worst times/places to make passes.

Or, just disclose track and the DA, alot of people do that.

Reason it kinda matters is this..... depending on where and when, a car could vary by as much as a 1/2 second, maybe more... it does usually save you some uneeded ??'s about your sig.

damon_Z

Using http://wahiduddin.net/calc/calc_hp_dp.htm, my recorded weather conditions above, and a track elevation of 98.4 feet, here is the info that I came up with.

For the 12/6/04 best runs,

Relative Horsepower: 103.3%
Air Density: 1.208 kg/m3
Relative Air Density: 98.6%
Density Altitude: 493 feet
Virtual Temperature: 66.1 deg F
Absolute Air Pressure: 29.91 inches Hg
Vapor Pressure: 0.216 inches Hg
Relative Humidity: 35.1 %
Dyno Correction Factor: 0.968

For the 11/26/05 best runs,

Relative Horsepower: 106.7%
Air Density: 1.2601 kg/m3
Relative Air Density: 102.9%
Density Altitude: -950 feet
Virtual Temperature: 47.4 deg F
Absolute Air Pressure: 30.09 inches Hg
Vapor Pressure: 0.084 inches Hg
Relative Humidity: 26.1 %
Dyno Correction Factor: 0.937

So, if I was going to use both the location and DA in my sig, then I should use the DA based on the actual track elevation of 98.4 feet? Also, based on the comparison of Relative Horsepower between the two days above and my best dyno of 294.51 RWHP, would it be reasonable to assume that I gained 12.66 rwhp, because of the lower DA? Thanks in advance for the info.