Marc's Public Blog

The conference is going well, it's good to see my international linux hacker buddies again (some actually live close to me, but I only get to see them in Australia and Ottawa, funny that)

Yesterday was the good old Geeks vs Nerds game show. I had ended up on the judge pannel at linuxworld in the past, and was one of the contestants this time, along with ext2 hacker and former coworker Ted T'so. On the other side were 4 contestants form the Ubuntu team I had just had lunch with the previous day to talk shop.
It was a fun game, Jemery Allison as game show host was just great, and among the questions I answered, I made the mistake of giving the correct answer to what the origin of spam was (Monty Python, the meaning of life), and got a nice viking hat to wear while singing the spam song.









As for my talk on fighting spam with Exim and SA-Exim, it went well.

Current Music: The Thrillseekers - Synasthesia 2004 (ASOT 181 Top 20)
Current Mood: decent, you just don't sleep as well in coach. Funny that...

It was funny how people were telling me: "have a safe flight" when I was leaving for Australia (I'm speaking in Canberra at linux.conf.au ): I could just easily answer "oh, that'll be easy, I won't be the one flying the plane" :)

But anyway, during this crazy week, I managed to squeeze in a couple of more flights in a Cesna 152 with my instructor. Unfortunately, this will be the end of the Road for Justin and I as he is moving to Texas soon, so I'm switching instructors when I come back. I'll miss him actually, he was both a good teacher, and a smartass like me, so we got along great :)

My flight tuesday, we went accross the bay for my first time so that I could practise flying circles and rectangles around given points with a strong wind. I didn't expect it to be easy, and it wasn't :) The highlight is that I actually managed my first landing (i.e. without being rescued by the instructor)

As for my other flight (and last with Justin), that one was quite challenging too. First we went over skyline to the ocean where we usually train, but this time without me being able to see anything outside. I was flying instruments only with some kind of helmet on my head that prevented me from seeing outside the plane. It was interesting (i.e. 0 outside references) and I actually didn't do that badly.
After that, we went to my dreaded slow flight excercise (slow flight = stall warning on the entire time, flying at 40 knots or less (i.e. less than 65kph, which is very slow for a plane to still stay in the air). I think I got a bit better at keeping the plane coordinated (i.e. rudder vs ailerons). As for stall recovery practise, I was a bit less freaked out this time, and even recovered the plane stalling sideways, on its way to a spin with proper rudder. Yay! (the conquer your fear thing)



Well, I guess the next flight with me holding the stick won't be before a couple of weeks or so. I'll try to use the time to read the books.

Can't read? Letters too small? Ok, then try the pictures here

I was looking forward to going to thunderhill again, it had been too long (since last year). It just wasn't quite done deal from the start though. After trying to guess from the weather reports whether it was going to rain monday or not, it first looked like it wasn't so I mounted my other wheels with Toyo RA-1s to replace the current "winter" tires (Toyo T1-S) a couple of days before the weekend.
On saturday morning, I managed to flat-spot my front right tire while bedding / testing my newly installed brake pads. Swell... At this point my options were to mount the tire in the wrong place (left back) and worry about the weather reports that had switched back to partial rain (those tires were not ready for rain at all since they mostly had the sticky rubber left on them, but little tread), or to take the backup car.
It came close to that, until Larry nicely answered a post on BAMO and offered to sell me his brand new RA-1s that were sitting in a garage (turned out it was the only way to get those on a saturday as all the possible warehouses in California didn't have them for same day delivery). Some running around to pick them up and get them mounted, by late saturday, I was all set. Yeah!

On the drive to thunderhill on sunday evening, I refueled at some Arco on the way, and noticed that my EGTs (exhaust gas temperatures) were shooting a bit high (more than 800C) at 110mph, so I just drove an almost decent speed on 505/5. That should have been a hint that things were slightly amiss already.
The next morning, I filled the empty portion of my tank with 100 octane, but that was only 4.5 gallons out of 12.7.

I first went out with my student to show him around the track in my car, and then later in his. He had a lot to learn, but eh, it was his first time, so that's normal.
After that, I went to have a little more fun on the track, but soon realized that my EGTs were really getting out of control. So, I called tech support (aka JasonC), took notes on what to reprogram in the Tec-II, and went to a support technician (aka MattY) to make sure the fuel enrichment and timing advance were done properly.
This helped a little bit, but still, I was running quite hot. Since Carlos was having the same issue and we both had gotten Arco 91 Kalifornia crapola gas, we figured that this week's Arco gas was probably watered down or something. We both added more fuel in our respective maps and messed with timing some more, which helped a bit. It also got a bit better for me after another more aggressive enrichment tune, and 6 more gallons of 100 octane in my tank once I had burned some by mid-day.
This is also around the time that I obliterated my AC/power steering belt (luckily it was that one), which in hindsight may be related to the high EGTs I was having, and a small exhaust leak (I think this caused my map sensor problem later). Anyway, I got to drive the last 4 sessions with no power steering, which made the drive a lot more intense (incidently, my back and shoulders were fairly sore the next day from pushing/pulling the steering wheel with such high gearing an no assist).


Matt "I'm too cool for my hair" Y


Carlos "I'm faster than you, but I can't drive 10 10th right now"


Jason "My blower is bigger than your turbo, so there!" W


Marc "Look at the back of my car, that's all you'll see Carlos" M




bling bling! represent! :)

By the end of the day, I was able to run the open track at full bore and came down to 2:18-ish (maybe 2:17), which was decent but not as good as I did last time when I didn't have all those mechanical problems and was much more focussed on driving and shaving off imperfections. Eh, at least I got a nice "you are positively insane" comment from the last passenger I got. All in a day's work... :)
Just for the record if you were wondering :), I never got close to losing control of the car, left the track with even one wheel, or made any dodgy pass, but with the RA-1s, I could drive very hard and keep a nice controlled yaw angle through turn 2. For that matter, even Bonni tried to get me off track by getting off turn 10 backwards and throwing dirt right in front of my car, but she failed too :)




Now, on the mechanical side, my clutch started acting up again, just like last time I went to TH: somehow it wouldn't always downshift from 4th to 3rd before turn 2, or 2nd to 3rd in turn 11 (mostly due to temperature apparently). This was annoying in itself, but on top of that in turn 11 while struggling to shift back to 3rd, I must have messed up a bit, and the gear somehow slipped in 1st, when I was at the top of 2. Ouch!!! I was actually expecting to see my engine drop on the road in my rear view mirror after that, but somehow it was still working...

Things became more gloom when I came back to my car that was idling on the paddocks to circulate oil through the turbo while it was spinning down and cooling off, and I noticed that the engine wasn't running anymore. Ok, maybe a fluke, so we drive to Willows to refuel, and when I'm ready to leave with my BAMO buddies, my car half starts and dies, and then won't start. Damn...
I pull out the laptop and connect to the engine diagnostic/reprogram port, and notice that one of the sensors is reporting failures: the MAP sensor (manifold air pressure). The Bamo buddies who had stopped to help me start looking at it, MattY at the laptop, and Carlos at the engine bay, and Carlos finds that one of my vacuum lines by the manifold was very hard and half pinched (hard due to temperature under the hood I'm sure, and pinched due to poor routing). Carlos cut it, re-routed it, and that took care of it.





We head out on Hwy5 south, but I end up driving slow: 55-60mph because I noticed that my EGTs are quite high. Argh... After pulling over, I tried to re-upload my engine map from the track (over-rich) even if I'm not supposed to need it and it might knock with less 100 octane gas in the tank. Car barely starts and move after that upload. Argh! Ok, now I try the middle map I had (a little less rich), and the serial connection fails half way through the upload, and I can't see the engine computer on my laptop after that anymore. Argh, argh, argh!
At this point, I was quite stressed because it looked like a half upload was a failure you couldn't recover from. Yet, somehow after restarting the stupid wintec2 crap software, I finally got an upload to work, and the car was finally on its way. EGTs were still high (more than 800C for cruising), but I was able to drive 85mph or so.
Then, I noticed on the way while looking at the real time engine stats on the laptop that it was showing much lower RPMs than I was driving (2900 rpm when I was doing 4500 or so). Since I know my gearing, I knew that my dashboard was right, and the laptop (and therefore ECU) wrong. While I'm not much of a mechanic, I knew enough that my ECU being off on RPMs by 1800rpm is very wrong. For that matter, my engine won't run if it's off by an 8th of a turn, never mind more than ten thousand times that. Anyway, the car limped along up to Mell's diner on Hwy 80, and after talking to tech support (JasonC), I re-routed the crank position sensor wire away from the ignition wires which were apparently messing with the electrical signal (Jason also said that the Tec-II has a weird failsafe mode where it apparently runs the engine without really knowing what position it's in)

After a dinner at Mel's with the BAMO guys, the car started fine and showed the correct RPMs, so we headed for the freeway, where I proceeded to drive 45mph this time due to even higher EGTs :( The convoy nicely pulled over for me again, and Matt helped me look into the problem again. Since the RPMs were now fixed, we reset the original map (the non enriched one), and Matt slightly tweaked it. After a quick test drive the car really seemed ok this time, and we were able to finish the drive home.
This was frankly more excitement than I was hoping for, and I'm not quite sure what state the car is in right now, but I'll have John look at it.
Either way, I'm somehow still happy I was at thunderhill with the BAMO crew and the miata, and thank you so much to all the people who helped me and waited for me on the way back.

Moral of the story: if you have a Tec-II, don't leave home without your laptop, a cell phone, and your tech support numbers :)

Anyway, you can browse the pictures here

It does in a car, but even more in a plane.
This morning, after practising "flying" by going from Sunnyvale to the San Carlos airport (Redwood Shores, by Oracle) in about 10mn :) (kind of forgot about the DST switch), I got to the airport on time for my appointment.
Today was slow flight practise (down to 50knots, which is only a measly 95kph), which was ok until we turned it into stall inducing and recovery.
First, to stall the plane (Cessna 152) is hard, it just doesn't want to and you really have to push it (well pull on the stick) a *lot*. First, I was kind of failing because I was unconsciously not pulling enough, just because it didn't seem like a good thing to do :)
Recovery wasn't as much of a problem as creating a clean stall: I was getting the plane sideways at 40knots pointing up and got fairly close to inducing spins (well, maybe not, but it felt like it). By the end of practise, I was fairly nerve wracked (stalling and intentionally putting the plane out of control just sucked). Although on the way back I was half tuning out, I actually more or less managed the landing.

Anyway I noticed that my car shakes a bit around 110mph. One of my tires must be slightly out of balance. Damn... Oh well, that shouldn't matter too much for the track. I'm not above 110mph for too long on the circuit.
We'll see how it goes tomorrow.

Current Music: AVB - ASOT 82
Current Mood: Good

After confirming that it would be impossible to buy a new set of RA-1s today, and having posted to the BAMO list, I got a few replies with offers and suggestions, including a friend who had a set of brand new RA-1s setting around at a shop in Santa Clara. Talk about luck.
He gave me his set in exchange for my old tires and some money :) and I got his mounted in time before the shops closed, and to realize after driving off that some of the balance weights they put in were scraping against my back RX-7 calipers (horrible metal scraping noise). Tss, can't they even test a car after putting tires on...
Anyway, I found another firestone affiliated place where they nicely agreed to fix the wheel and rebalance it (took all of 10mn). I tipped the guy for saving me a longer drive back to the other shop that was closing anyway.
Now, I'm out of excuses for not bringing my miata to the track monday :)

In other car news, some guys hacked their honda prius to run in electric mode only, swapped the batteries and added a plug to recharge the car. They now get more than 100mpg (using off the grid electricity to recharge). As much as I was really not convinced by the hybrids and their inability to run on electric for even 20 to 30 miles, or to be recharged without using gas, those modded cars are really what's it's all about. Hopefully the carmarkers will get a clue.
NYT with soul selling registration article here