I took the Max to KCIR http://www.kcir.net/ on Friday night, for the test-n-tune session. The place was a madhouse, what with the track getting ready for the Freaker's Ball on Saturday and staging being done through the two back lanes, but I still managed to get a few runs in:

------------Run_1--------Run_2---------Run_3--------Run_4-------
R/T________.588________.118_________.348_________.09 5
60'________2.124_______2.187________2.112________2 .166
330'_______5.746_______5.896________5.805________6 .022
1/8________8.757_______8.908________8.822________9.1 15
MPH_______80.64_______80.50________81.06________79 .53
1000_______11.388______11.528_______11.448_______1 1.773
1/4________13.615______13.751_______13.886_______14. 011
MPH_______101.90______101.99________87.47________1 01.61

These runs were all with a 50-shot on launch and second-stage 75-shot after shift into second gear. I shut down around mid-point on the third pass because I was matched with an extreme hot-rod truck that ran 11.909 and 112.19 in the other lane. After looking at the numbers, I should have stayed in the throttle - might have been my best run of the evening and also ever! The 13.615 is my PB ever.

Temperature was around 60 degrees and no fog (river bottom area). I think altitude is around 800' - not sure. Track was prepped well, and very crowded that night. The return road went through two tents and around some portable stages and light towers - confusion ruled!

My new engine is working well, and the Infiniti VLSD tranny is GREAT! Makes a great burnout on BFG DRs - I used the 255x50x16s that night. The plugs looked great after each run, with no signs of detonation or preignition. I'll be back next week - either Wednesday or Friday, depending on weather. That's the last week of Wed-Fri test-n-tunes, then November they are open on Sundays, then close for the winter. I'm not done yet.....

 

Good job. I don't understand why you let off on run 3 though. Did you let off simply because you were racing a faster car? KCIR is around 1100' I think btw. What's the nearest city to KCIR and what time were you making your runs. I can tell you what the DA was which is what you really what you want to look at when you start considering the weather.

 

I'm still a little cautious ( OK, gunshy) when pushing the car hard - something about just replacing the engine..... I'm really not sure why I pulled back - that truck ran a 11.909/112.19 w'R/T .076, and 60' of 1.653. Plus the sucker just ate me off the line and pulled me all the way - he moved really fast off the line. Just a joy to watch. I get stomped lots of times at that track - they get cars from four states there, usually twice a week, plus weekends, so 200+ cars is common, plus monster bikes and modified ATVs that run the 1/8 in 8 seconds! Eight staging lanes plus two Hod Rod lanes for the really bad boys. My poor ol' street Maxima doesn't have much of a chance.

KCIR is Kansas City International Raceway, by the way. On the east side of Kansas City, in Missouri, in the Blue River valley. It's a 90-mile drive, each way, for me. Try their website link (see above) - it has maps for location and weather. What's "DA" ??? Tell me more..

Those four passes were on Oct. 21 at 6:57, 7:43, 7:55, and 8:08 PM. On pass #1, an extreme smallblock '55 Chevy beat me with a 12.548/104.11, but technically he redlighted with a R/T of -.005 - not that anybody cares there. Pass #2 was against a stock Honda, at 16.715/81.77. Pass #3 I just detailed above. Pass #4 I won against a losing 13.732/108.99 !! His R/T was .958 and 60' was 2.677. My R/T of .095 and 60' of 2.166 and ET of 14.011 was enough for the win by .5846, according to the slip. I think my bottle was too cold for #4. Pressure was down to 900psi, and I started with a full 15lb Hi-Flow NX bottle.

Last night was really random choices of partners, due to the prep for the big Halloween party - the Freakers' Ball. Hope they enjoyed the Saturday rains there!

I'm still learning lots the hard way - on the strip. I wonder about my cars' top end - I've never gotten above 102 MPH... It's like above a combined 125-shot, there is no more power at the top end. Well, I've still got next week and all November to try something else.

 

DA is density altitude. Pilots use it to calculate all sorts of things such as takeoff roll length, etc. It's a measure of altitude corrected for pressure and temperature.

Drag racers use it to know how good the air was for racing in a single numerical format. You can use it to figure out if the air you were running in was great for racing, sucked for racing, was average, etc.

The reason I asked for the times of the runs is because I will grab the weather data for the nearest ASOS or AWOS or whatever to KCIR and figure out your DA and that will tell you how good the air was at the time you were at the track.

 

Sounds like something to know ! If you have temp, barometric pressure, humidity, and elevation, can this be calculated trackside?

 

Yeah it wouldn't be easy to do by hand though. You could get a flight computer, either manual or electronic and do it with that. I've got one and I don't even bother taking it to the track. It's just easier to look at the weather report from the nearest airport after I get home and calculate it then. You can do that online at various aviation websites without needing to purchase a flight computer.

 

So is this something you do after an evening at the track? Is there any advantage to looking up this number before going?

My nearest airports are Kansas City International (MCI, I believe) and Forbes Field in Topeka KS. (military and commercial, also next to the local strip) plus the Topeka private airport, Billard Field. So there is a website or two where you can look up conditions at these fields? This sounds important to know....


You must be either a pilot or crew on commercial services, right?

 

A lot of the old school guys would use this info at the track to change jet size on their carbs (ie-differing DA's means differering O2 content hence more/less fuel required to get the desired tuned A/F ratio).

For us it's probably more of a comparison tool to see how the car runs in different temps, pressures etc. Using MAF based tuning (like our cars) the A/F should be pretty close as the ECU knows the exact mass of air coming in at any given temp/pressure. And humidity makes much less of a difference in DA compared to temp/pressure/elevation.

I think I remember reading that Neal does fly.. something I've been wanting to get into forever but never quite got around to getting my license. I've been flying many times with a friend who's got a license and I have flown a 4-seater Cessna on occasion (shh don't tell anyone... ). It's tons of fun.

Neal.. if you happen to read this... you gonna send me that CarTest file or what? lol

 

Thanks for the info, this makes Neal's comment much clearer:

"Drag racers use it to know how good the air was for racing in a single numerical format. You can use it to figure out if the air you were running in was great for racing, sucked for racing, was average, etc."

The DA can help you understand what happened at the track..... Some record-keeping and you might be able to use current DAs to change settings - like fuel pressures w/N2O, maybe??

Anyway, thanks for the explanations. "It's always something"