View Single Post
Old 09-30-2013, 04:09 PM   #218
Fair
Senior Member
 
Join Date: Nov 2012
Posts: 333
Default

continued from above


Left: After conferring with TT officials, instead of assuming my car would dyno low at altitude, I revised it to the latest tested number

So if you got a dyno chit, you went straight from the scales to the dyno, 50 feet away. Nobody could touch the car but the driver, and you couldn't open the hood or do anything else. Once it was your turn the dyno operators took the car from you, used an elaborate series of ramps to get it up onto their mobile Dynojet trailer, strapped it to the rollers, and got some fans going on the radiator and opened the hood. Once the engine was up to speed in the 1:1 transmission gear they asked about redline RPMs or rev limiters, then did three back-to-back dyno pulls. Vrooom.... vroom.... vroom. Didn't take 60 seconds. Then if your car made more than your claimed dyno number ("popped dyno" or "blew dyno"), even by 1 a hp, you got a session DQ. Then the NASA TT directors would calculate your latest dyno and weight number, and if that ratio was over your class minimum, ALL of your previous sessions times back to your last successful dyno/weight check were thrown out. This matters for later, so keep this in mind.

Now that I know how this works I would have ASKED for a dyno earlier in the week. Because a successful dyno/weight check means your times up to that point are SAFE. Just like when we come in from a TT session early, to "bank" our times. Why? Because if you have a 4-off or a spin during a TT session, you lose ALL of your times in that session (session DQ). It has happened to me twice in the past 6 years (spin or off during TT), and it sucks. So when you know you have a good lap time in the books (from watching your onboard lap timer), most of us come the hell in! Again, this matters for later.

They had similar procedures for virtually every NASA race group, but I'm sure there were small differences I don't know about. In any Championship W2W race, for instance, if a driver blew minimum weight or blew the dyno, they were DQ'd and everyone moves up a space in the standings. So everyone was watching the dyno all week. And yes, even at 4500 feet of elevation, they use an SAE correction factor to correct for that. And it was huge, close to a 20% correction! I'm used to seeing 0-2% corrections here in Texas, sometimes even negative 1-2% for SAE. So you couldn't just rely on "the elevation will soften my numbers", no sir. You have to factor that in. I was a FOOL for not getting a dyno check before the event started and for not ASKING for a dyno during the event. I got lucky, I guess, but if you were in the top 3 during the week you saw the dyno, trust me. I wasn't in the top three until.... well, the very end. I'll get to that.

Race Coverage - Day By Day

I don't know if I mentioned this earlier but the course being run for the week of Nationals for ALL race groups was the 3.0 mile "Outer Loop" CCW, and there were no HPDE groups running at Nationals. This 3 mile course is the fastest configuration of the 4 possible track layouts at Miller, and has many high speed turns and a LONG 3500' front straight. There is some elevation change in a couple of corners, but for the most part it was like most other desert tracks I've run: flat and with few visual markers. This meant many corners looked identical, which confused me a bit. I have never run this track before and struggled all week, learning the layout. And we fought all week to find balance with the set-up...



Like we do for every NASA TT event, we made our own maps in case they didn't hand any out. They had great maps, though

I will break up my "race coverage" into the 4 days we had to get our best lap time. Every session from all 4 days of Nationals counted for TT, and you only had to bag one fast lap in one of the 9 official sessions (the Warm-up session was the first of 10, really, but it didn't count towards times). Some days we had 3 sessions and some days we had 2, which I will explain below.

Results: http://timingscoring.drivenasa.com/N...Championships/ (TT3 was in Group H)

I missed one session due to rain and another where we had to work on the car, but ran every other one and thankfully had no DSQs (a spin or 4 off will net you a DSQ). I had some close calls, and came in early to "bank" a good lap time when I noted a decent time on my AIM Solo display (which was extremely accurate all week, matching the official transponder times usually to the hundredth place).

Day 1 - Thursday

TT had our first mandatory meeting of the week at 8:30 am this day (one of 9 meetings we had that week), where we went over the basics, then TT1/2/3/U (Group H) had our first "Warm Up" session at 10:30 am (TTB-TTF ran in a separate run group all week - Group C). I went out in this session on those well worn R6 tires we brought on the grey wheels and fumbled my way around the track. Car was LOOSE at speed! Aero balance felt terrible, and any corners over 80 mph the car wanted to be sideways. The slow speed corners felt fine, but it was a complete handful everywhere else. I thought we had this sorted at our ECR test, but that track's fastest corners are probably sub-65 mph. Some of the corners here at Miller I was entering at 100-150+ mph. Scary fast, and I was working on my lines and my "testicular fortitude" in every session. I stayed out in the Warm Up for the entire time and had a best lap of 2:10.804 on Lap 5, and a 2:10.9 on the lap before, neither of which was fast. The quickest TT3 car in this session was a red E36 325is, which had an S54 3.2L M3 engine swap and good aero, driven by an old autocross buddy Chris Mayfield. He ran a 2:06.448, so he was fast right out of the gate. Ken Smith in the yellow ST3/TT3 C5 Z06 ran a 2:09.306 in that session (and was broken down on the side of the front straight, then came on the hook), with two faster TT3 cars between him and Mayfield. The Miller track crew did an excellent job and was doing "hot tows" all week (towing cars in with rolling local yellows, while keeping the racers going). I was only 5th fastest out of the 11 cars running in the TT3 class (at this point - we saw 12 different TT3 cars by week's end), and well over 5 seconds back... yikes. TT3 was the largest TT class of the event, by a good margin over any other (here's group C).


Print-outs showing results from Day 1's 3 TT sessions: The TT Warm up, TT Session 1 and TT session 2

In that Thursday Warm-Up session I ran so many consecutive hot laps that I saw some warmer than anticipated engine temps on lap 6, even with the lowest ambient temps of the day (high 70s). On Lap 6 the temp gauge shot up to maybe 3/4 of the range from "C" to "H", which is warmer than we ever see in this car. It was not that warm outside yet, so I chalked it up to the thin air here at 4500 feet of altitude and maybe still having an air bubble passing through the newly set-up cooling system (I added some distilled water in the pits after this). Talking to other drivers they were seeing the occasional warm temp readings, too, and I was told by many "high altitude racers" to be on the watch for this at Miller. I took a cool down lap and stayed well out of people's way while coming in, and with a 3 mile course the cool down laps can take a while. Within 30 seconds the engine temps came back to the "middle" of the range. This happened two more times during the week, saw a warm temp after too many hot laps that was corrected in the first cool down lap..



Navigating the "Attitudes", 3 S-curves right in a row with some wide, tall and nasty curbing

continued below
Fair is offline