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GameboyRMH
GameboyRMH MegaDork
8/17/17 10:06 a.m.

Haven't been doing much with the car, a little tuning here and there, and recently I took it to get the crank sensor bracket modified again because the alternator & water pump belt is bowing outward at high RPMs and shaving itself away on it. But it looks like the next autocross which was originally scheduled for this weekend will be postponed to a date when I'm out of the country. The only upside is that it's being done because the track's being partially repaved, and a smooth surface would be a massive advantage for my car. I was starting to consider going for a more rally-oriented suspension because of how bumpy this track is.

GameboyRMH
GameboyRMH MegaDork
10/10/17 10:24 a.m.

So there was a track day on Sunday. Only work I'd done since the crank sensor bracket mod was some tuning, mostly on the accel enrich settings. This setting works well, it's almost impossible to get burst knock now:

But on the warmup lap (warmup for brakes and tires anyway, the engine was already warmed up and I was running it hard from the start) I started to hear a faint scraping/whistling noise. My wrecked-engine PTSD sprung into action and told me to get back to the pits ASAP. As I drove back in I could hardly guess what it might be, it seemed to have something to do with engine RPMs, but maybe a rear sway bar tab came loose again. When I popped the hood I saw some smoke coming from the pulley side of the engine. I had a look around and soon saw the problem:

Half the timing belt had been chewed off by something. No idea what. The crank sensor bracket might be an immediate suspect but it's not that close to the timing belt. You'll also notice the fresh streaks on the alternator belt, indicating that the sensor bracket is still making contact with that belt at the very highest RPMs, so it needs some more clearancing. One suggestion I got is that the stock timing indicator bracket might've been bent close enough to the timing belt to slice it apart when it bows out at high RPMs, apparently it doesn't take much. I don't know where the oil on the timing wheels came from. Oil has spewed from the dipstick tube before, but I had the dipstick velcro-strapped down and didn't see any oil around the top of the tube. Might've been a spill from an oil change the day before.

Anyway I got permission to leave the car at the track for a couple days, I'll take it to the shop that did the crank sensor bracket mods this evening.

GameboyRMH
GameboyRMH MegaDork
10/10/17 10:42 a.m.

Some bonus track day pics. It was a pretty ballin' track day, I think I had the plainest car there:

The famous "RX3" with the front clamshell off:

oldeskewltoy
oldeskewltoy UltraDork
10/10/17 12:17 p.m.

not saying this is your belt shredding issue.... 

I've seen the tensioner spring fall off before.... 

GameboyRMH
GameboyRMH MegaDork
10/27/17 6:36 p.m.

Turns out a backed-out bolt is what shredded the belt, also the cam and crank seals were both leaking on the front of the engine, which is odd because they're fairly new. Maybe too much crankcase pressure? I'm thinking I should add a PCV valve to the crank vent system to be safe.

GameboyRMH
GameboyRMH MegaDork
10/31/17 9:19 p.m.

Got the car back tonight, on top of the timing belt and crank sensor bracket problems, the car also had a backed-out alternator bolt, dirty alternator output connector, and a coolant hard line with a tiny leak. Also it seems that my WB02 controller has failed, possibly from getting too close to the exhaust, I'll have to take a closer look tomorrow evening.

GameboyRMH
GameboyRMH MegaDork
11/2/17 8:57 a.m.

There were no physical signs of damage to the WB02 controller, but electronically it looks very FUBARed. It isn't outputting calibration values on startup as it should and outputs noisy nonsense readings of 9.7:1 (below the normal minimum output value)~15:1 while driving. So it's disabled for now, luckily I got plenty of tuning in before this happened. After the autocross I'll get the wiring checked just in case there's a bad connection somewhere, if not I'll get a replacement smuggled in around March next year.

I might be able to bring home a trophy for the first time in quite a few years at the end of this season. I'm one of 4 competitors tied for 4th in 2wd class, behind my navigator who's just 2 points ahead. One guy who just bought a Toyobaru and took the 2WD class win at the last event is just 2 points behind. I've beaten Toyobarus before, but with drivers of questionable skill, this guy I used to see at track days when I was a teenager so I know he has experience.

My car is the 2nd least powerful of any of the potential contenders for 3rd (after my navigator's rally car), one of which is the electric sevenesque - I dread the day when the driver figures out that if he were to artificially limit the car's power output for autocross to 1/4~1/3 of full power, it would give his right foot a sporting chance at controlling wheelspin (and the related gratuitous spinouts) and make the car nearly as dominant in autocross as it is in drag racing.

GameboyRMH
GameboyRMH MegaDork
11/15/17 7:15 p.m.

Finally have some time to recap the autocross on the weekend before last. Took the car on the day before to get the alignment checked, at a different shop this time. The guy did a good job, and this is a shop with a laser alignment machine I can get the car to on my own without taking a day off work. I still think my usual alignment shop was trying to give me a right-turn-biased setup to be faster around the bigger track here, even though that's not a course I'll ever compete on.

The morning of the event, my offroad rally navigator wanted to share since he was between cars, and he'd shared his rally car with me once before, so it's only fair. I figured the car was pretty well sorted out by now. On the first run I went out and one of the sway bar link tabs slipped again, so I had to abandon the run and fix that. At the end of my second run I got a decent time but heard that all of the course workers were smelling coolant from my car, and now I could smell it too. I popped the hood and saw that one of the caps over the ports that would've gone to the heater had burst open and was sprinkling coolant onto the gearbox. I called a nearby parts shop to reserve a cap and called my dad to bring it to me with some coolant from home. He got there just before the end of run 3 so I actually didn't miss a run. I rushed out there, forgetting to start the data logger or roll down my windows, and surprisingly cut 4 seconds off my previous run. I didn't think I could cut off more than 2.

My 4th run wasn't as fast as the 3rd. So I got 5th in 2wd for the event (behind the guy in his new Toyobaru, a top rally driver in an e36 rallycross car, and two guys in an R33) and 4th in 2wd for the season. If the previous event hadn't been rescheduled to when I wasn't here, I easily could've got 3rd or even 2nd. But, it's clear now that this car can't be a championship contender anymore. The guy with the new Toyobaru beat me by about 9 seconds, and the guy in the electric Sevenesque almost took an even faster time before he plowed past the finish gate. Before I swapped in the 4AGE I was usually within 2 seconds of FTD. So I've started spreading the word that I'm thinking about selling the car. I don't know what I could afford to replace it with that would be competitive, but the best platforms to start with around here would probably be an IS200 or late RX8.

GameboyRMH
GameboyRMH MegaDork
12/22/17 2:12 p.m.

Now to recap the track day I did a couple weeks ago.

To prevent any more coolant caps from blowing out, I changed them for a looped line. I couldn't find any shaped lines to make the sharp ~270deg bend, but the hydraulics specialty shop recommended a silicone line and assured me that coolant wouldn't seep through it:

These are the two ports where the caps were:

I also added a PCV valve connecting before the throttle body to give blowby gases another path in case the catch can was too restrictive:

This time at the track, I was focusing more on lines and less on finding the car's limits, so the times weren't as quick. I was worried the looped heater line might not be good for coolant flow, but there were no heat problems, the needle stayed centered and the data logger shows that engine temps never went above 203F. The only problems I had are first that the engine felt weak above 6500rpm, I'd just added 1deg of advance at 6krpm+  trying to address a fall-off in power at high RPMs, thinking that overly conservative timing could be the cause, but that seemed to make it worse. I'll undo that and try retarding cam timing next. Second, the alternator belt is still scraping on the crank sensor bracket at high revs, so I'll have to get that modified again. For this data log, I also added in the megasquirt's log file for engine data:

 

GameboyRMH
GameboyRMH MegaDork
1/9/18 7:54 p.m.

So recently I've been thinking about what to do with the car this year and looking very closely at the wheels. Since the car can't be competitive anymore, there's no point in rushing for more performance, I might as well take my time and do things properly the first time. Even 15x8s are a tight fit, spacers would most likely be needed in the rear. So I'll work toward a rear pushrod conversion to make ample room for 15x8s without spacers, or ideally even 15x9s with 245-wide tires. This will also give me room to go back to the old progressive springs which I think performed a little better, the rear is a bit jittery with linear springs. I could then move the springs currently in the rear to the front with tender springs for better tire clearance and droop travel.

First though, I want to get the rust fixed and get some fresh paint on the car. Since performance mods aren't priority #1 for the first time ever, now's the perfect time. I may also reduce the depth of the spare tire well to make more room for a diffuser later on. And I figure the car would be a lot more pleasant to drive with working AC. Probably next weekend I'll get the problems I found at the last track day looked at.

And here's a little bonus, the full-length video from that last track day where I chase down a Toyobaru. I'm sure I could get even closer with my last thousand revs of useful powerband back.

 

GameboyRMH
GameboyRMH MegaDork
3/23/18 9:05 a.m.

I have an huge backlog of stuff to post for this thread and on my Samurai, it's the busiest part of the racing season and the busiest time of year at work, but I just saw loosecannon say that he's jealous of people who don't have to wait for snow to melt, so it's time to make living in the Caribbean pay for itself cheeky

First, here's a quick vid of a track day back in February. The day before I got an alignment and the battery was drained in the process again, and it failed on the track that day, causing the car to go into limp mode and later, voltage-induced sync losses. And then the starter motor finally died completely. Here are the only good laps I got in (no data due to voltage problems):


Reducing ignition advance eliminated the high-RPM power loss problems. Had to get a push-start to leave the track after this, drove it straight to the electrician to look at these problems, I'll give the rest of that story in a later post...

GameboyRMH
GameboyRMH MegaDork
4/8/18 8:30 p.m.

The backlog continues, now I have 2 events to cover.

So the autocross was soon after the track day back in February, I had both a dead battery and a bad starter. The starter couldn't be fixed so a replacement was found. But the gear wasn't moving far enough outward on that one, so I had to get it exchanged, so I had a dud starter for the autocross and had to get push-starts.

First run was decent, second run I had a brainfart at the turnaround point near the start, went around one too many cones and DNF'd. 3rd run was an improvement, then I got the suggestion to try handbraking instead of driving around the far side turnaround which was full of rubble. That shaved off nearly 4 seconds on my final run, good enough for 5th in class behind the electric sevenesque, a Toyobaru and 2 top drivers in a 3-litre BMW rally car.

After this it needed some more time at the electrician for a second starter replacement, a troublesome gauge wire and a replacement Spartan Lambda 2.

GameboyRMH
GameboyRMH MegaDork
4/23/18 10:50 a.m.

OK so now it's time to update on April's autocross. I got the starter replaced (again), got the gauge fixed and the new WBO2 system installed, so the car was working well. Weather wasn't great, it was hot and sunny but there were occasional bursts of moderate to heavy rain, it fell pretty heavily during the course walk in fact, plus there was a thick layer of dirt on the track in the middle of the course. Bernie Ecclestone's dream! We also had electronic timing for the first time ever.

On the first run I went out and...set a pretty good first run. The turnaround in the box could've been faster, and the turnaround at the tires could've used some handbrake to reduce the wide plowing, but it was good otherwise. Heading toward the turnaround by the tires was the first time I had a reason to bounce off my rev limiter, it was pretty violent with retard from 8000-8200 leading to fuel & spark cut, so after this run I changed it to retard from 7800-8300 leading to fuel & spark cut.

The trouble is that when I tried to make my later runs faster, I messed up on the dirt in the middle of the course. In retrospect, even though the rain never fell close enough to one of my runs that I had to drive on a wet course, I think the rain was changing the condition of the dirt and making it more slippery over time. On my last official run, I was extra careful to take it slow over the dirt and got into a big 180-degree spin, rather than just plowing wide or getting too sideways as on previous runs.

So my first run ended up being my fastest official run of the day.

On my fun run I think I showed that there was room for a run in the 1:46s with better driving, I got a 1:47-something plus one cone down, even though I had a brainfart and almost went the wrong way around a cone.

So I ended up 5th in class behind the two drivers in the 3.0 BMW rally car, the Toyobaru and a new competitor in a Nissan March-based SR20-powered race car. If I'd driven better I might've been able to move up one position ahead of the "March." A former champion who was working the course said that my car seemed to be the fastest in the tight part of the course and that softer rear damping might help on the dirt. I'd increased rear rebound damping to get more rotation in track driving, but softer rear settings did work well in autocross, so I might try a softer rear setting next time.

The electric Sevenesque wasn't competing because its battery pack burned down in a drag race a couple of weeks before and the new batteries hadn't arrived yet. I did plan to beat some cars with reliability, but that's the last one I would've expected! So in class points I could have a shot at 3rd this year. Right now I'm 4th in class and overall.

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