Just completed my first logging session with the Predator

No. just seems that when most people add fuel they add more in the top 2 ranges. 1st is about the only time you hit the bottom rpm range and there's a different load due to gearing? Just the settings you're starting from with the canned tunes? don't know. That's how it seems to work out starting with a canned tune for the base and then adding fuel for a lower afr or to get knr about the same through the entire range?

 

Well, I'm sitting here waiting to get through the gates at the track.

My goal is to try and maximize my performance at the track. I suppose that means I'm looking at an ideal AFR and with that I'm sure the ST knk would be all but eliminated.

Since it's difficult to post from my Blackberry maybe more suggestions can be sent to my email? Lol

I'd be happy improving my ET and trap speed.

One can only hope.

 

Well, "hope" didn't make a darn bit of difference.

First run of the night was the best at 13.998 @ 99.91 mph, 60' of 2.234. Again, the car felt as if it was bogging down and not wanting to go.

Couldn't data log, they don't allow loose objects in the car. Could probably have logged with the Predator, but without being able to view the log with the DataViewer it's not all that useful.

Not sure where to go from here.

 

You may want to use this DA caculator. Starting at about 3400 feet says you are DA challenged. Not an exact science, but gives you a better comparison. I did a 2:00PM check yesterday and your DA was 5050 feet. Corrected ET on a 14.00 run would be 13.123. That is pretty normal for a good running basicly stock SRT8.
If your running F1's or RSA's you have the ability to get your 60' down to a 1.90 to a 2.00 with some practice.

Put in the time of your run last night along with your et and mph. You might be surprised at what your corrected times are.

http://www.dragtimes.com/da-density...ack=147&month=7&day=17&year=2009&time=2:00 PM

 

Thanks for that. I have that link, but I've been told that when it brings back the weather data it's incorrect (at least for us). I'll re-confirm this and post back. Regardless, I ran at just after 7:00 pm local time which would produce the following:

Conditions --------
Elevation: 3380 ft
Air Temp: 78.8ºF
Pressure: 30.14
Humidity: 36%

Produces --------
DA: 5323 ft
ET: 13.998
Trap: 99.91 mph

Adjusted --------
ET: 13.071
Trap: 106.966 mph

The issue I have with this, is that other similarly equipped SRT8's run mid-13's (13.4 - 13.6) with a lot higher trap speed (this is what is bugging me the most, typically 105-109 mph) on this same track under these same conditions.

I wish I could run down at sea level with some other SRT8's that are running as expected to compare properly.

 

Update: according to the Environment Canada website, here are the pertinent weather details for 7:00 pm local time

http://www.climate.weatheroffice.ec...ov=CA&StationID=2205&Year=2009&Month=7&Day=17

Temp: 24.5ºC == 76.1ºF
Humidity: 42%
Barometric Pressure: 89.65 kPa == 26.47 inHg

If you plug those numbers into the DA calculator you get a DA over 9000 ft. Doesn't seem possible. :erm:

 

That sure doesn't work. Are you sure on the barometric pressure? It shows over 30 on the Drag news calculator.

You have a .3 to .4 et pickup with an improvement in your 60' time. What are the other SRT8's doing on their 60' times?

 

On this track the 60' times are tough to get with street tires. VHT (sp?) isn't used so the over-powered imports with stock trannies don't blow up. A buddy of mine managed a 2.09 60' before the juice kicked in. He's running Nittos, I think. Yes, I have to improve my 60' times. Just having a hard time getting moving. Stalling the car up to 1100 or 1500 rpm doesn't seem to do anything except make the car bog down worse.

Yes, it comes directly from the Environment Canada website. I'll see if I can find other references when I return. We're off to a charity show and shine. Perhaps I'll spend a moment or two cleaning the bugs off the pumpkin. LOL

 

DA correction with that number is like an 11.90. So somethings amiss.

Have fun today.

 

Okay, this is a better link, I think these numbers are more accurate:
http://www.weatheroffice.gc.ca/trends_table/pages/yyc_imperial_e.html

Time: 7:00 pm local
Temp: 78ºF
Humidity: 39%
Pressure: 30.14
DA: 5337 ft
ET: 13.998
Trap: 99.91
Adjusted: 13.069 @ 106.985 MPH

The only real difference was the Humidity% recorded by the Density Altitude Calculator, it was low by about 3%. All in all, pretty close. I guess I don't feel so bad, but the car still feels like a dog and I still think it's trap speed is low, even after correction. LOL

The show and shine was a great time. Many beautful vintage and modern cars. The burnout competition was fun too. Made my car disappear in a huge cloud of white smoke. LOL

 

Well, I was wrong. But now I know why. I've discovered that the Barometric Pressure that is used on the DragTimes.com site is the Altimeter Setting (or sea level pressure, SLP) which can be calculated by hand, thus:

SLP = station pressure + (physical altitude / 1000)

I found this by doing a search on density altitude calculations and found this one that does it by hand. It's not totally accurate because it doesn't take into account the humidity, but it did shed some light on how the calcs work.
http://www.arcanamavens.com/LBSFiles/Shooting/Downloads/ManualDA/

So in my example (7:00 pm on July 17, 2009) the values are to be pulled from:
http://www.climate.weatheroffice.ec...ov=AB&StationID=2205&Year=2009&Month=7&Day=17

Station pressure = 89.65 kPa = 26.477 in-Hg
SLP = 26.477 + (3380 / 1000) = 29.857

Plugging the correct numbers into the DragTimes.com site:
Track Elevation: 3380 ft
Air temp: 76.1ºF (24.5ºC)
Barometric Pressure (SLP): 29.851 in-Hg
Relative Humidity: 42%

Calculates a DA = 5489 ft
ET: 13.998 sec
Trap Speed: 99.91 mph

Corrected: 13.041 @ 107.198 mph

Now, if I could just improve my 60' times, perhaps I'd have something to talk about.

Oh, and here's a quick video my daughter took of my attempt at a burn out.

 

Holy cow! talk about pressure to perform. If that didn't work you would have just had to shoot yourself. You couldn't even drive away since they had you chocked and backed up to a wall..:grin:

 

Ha ha, ya. Felt bad for the two Mustangs that couldn't even produce a puff of smoke. :whistle:

Part of the agreement that the organizers made with the fire and police department involved a little extra safety, hence the chocks. They even cut out a hole in the pavement and put in a cement pad just for the burnouts. All donated. It was an awesome day.

 

Well, thought I would get everyone caught up to what's been happening. After logging the car and updating the tune, the car still wasn't performing as desired, not to mention the inability to roast the tires at will. So, I decided to spend some money I don't have and purchased an email tune from RDP (Steve). I sent my original backup, the last tune written and a fairly comprehensive log file and Steve was kind enough to send back a custom tune.

The car is definitely more responsive now and feels like it's pulling stronger all the way through the RPM ranges. Even with ESP fully enabled I can stomp on the pedal from a stand-still and lay down a strip of rubber when I had never been able to do that before. I still think there's a little tweaking yet to be done in the tune, but for the first iteration, I'm very pleased.

I'm off to the drag strip in Edmonton on Friday. Castrol Raceway is better prepared and has a better DA (2200 ft) than Race City (5000+) in Calgary. I hope to see better ET's (low 13's) and trap speeds (107+ mph). That should prove if the email tune is on the right track. But, my main goal is to get sub-2.2 sec 60' times which should help with my ET's.