Wednesday, November 27, 2013

Some New Zip

After the last race, we have to get ourselves some new Zip.  A couple of us plan on doing some prep work the week after Thanksgiving.  We will unhook the wiring, hoses, intake, remove the radiator, driveshaft, exhaust.  Then the weekend after, we hope to pull the old (ventilated) engine out.

We will spruce up the spare engine with a new timing belt and some gaskets, then swap it in.

If you are really lucky, we will post photos :)

Sunday, November 24, 2013

Charlotte Chump Race - Take 2 Results

Saturday morning, race day!  Everybody was up bright and early and at the track well ahead of the driver's meeting.  Except Duncan, who had an alarm malfunction possibly related to user error.  The CTS-V made some sonic boom noises heading up I85, and he barely rolled into CMS at 6:31.

We were out of the driver's meeting, in the car, staged on pit row, and ready to rock.  But c'mon, Charlotte Motor Speedway Chump Racing ain't racing without some drama.  Mother nature did not cooperate.  It was so foggy, the guys in the control tower couldn't even see the cars on pit row.

Thick fog delayed the November CMS Chump race
A 15 min delay turned into a 30 min delay, then 60.  Finally, a few minutes after 8am, the fog had lifted enough for the green flag to fly.  There were 52 cars in the lineup, and after 65 minutes of frustration, there were some happy drivers out there.

Because two of our five teammates did not get a chance to drive at the last race, we inverted our driving order this time.  Jason was the first up.

The course was set up strictly on the oval.  The CMS Christmas light thing was set up in the infield.  To keep non-NASCAR drivers awake, with both hands on the wheel, Chump set up a chicane on both the front straight and the back straight.  The chicane at the front was fairly wide and not particularly tricky.  The chicane at the back was the opposite.  It really wasn't wide enough to go in two wide, and the exit of the chicane was a little tricky.  So this prompted a few spins at the front chicane, and a WHOLE LOT of screw ups on the back chicane.

The Charlotte race used the entire oval, with a chicane added in each straight as marked in yellow

Jason settled into the car well, with frequent interruptions for yellow flags.  He reported the temperature of the car would stay reasonable as long as he didn't run it too hard.  Short shifting at 4k or 5k rpm seemed to hold things together.  The car was handling well, and the brakes were phenomenal.  Top speed was around 105mph, a bit of an improvement from the last race.  Jason completed about 80 laps before roaring into pit row.

After a quick addition of five gallons of gas, Brad was up next.  With plenty of open track in front of him, Brad scooted around half a lap before doing a great job of exploring the tire wall in the back chicane.  After sliding to a stop about 2" from it (2:37 in the vid below), he waited for a chance to reverse and get back into the mix.

Another 30 minutes went by, with Zip6Racing showing as high as 13th or 14th place.  Then Brad put the finishing touches on a strong passing maneuver down the front stretch by managing a lurid slide and a complete 360 going into Turn 1.  No harm, no foul, no impact or crunched body panels, but good for a bit of a pucker.

Alas, the vg30 was fading.  An oil pressure warning light, set to go off when oil pressure dropped below 10 psi, went from flickering occasionally under heavy braking and low rpm, to flickering frequently under hard cornering.  Engine temps would only stay down if the car was kept below 4k rpm.

Roughly 128 laps into the race, Brad accelerated out of a chicane and knew something was wrong.  The car seemed to lack power, and was reluctant to pull up to speed.  A few hundred yards later... BOOM!  She blew:

This twisted chunk is what's left of a connecting rod that went through the oil pan
A now well-ventilated VG block
We got a tow back to the garage, and mourned our dead engine.  Even if we had a spare with us, it's questionable whether we would've had time to swap it in and get back on the track before the end of the race.  We packed up and headed home.  We'll be back!  In the coming weeks, we'll decide which of the 2014 races we want to shoot for.

Charlotte Chump Race - Take 2

As some of you may have known, ChumpCar was nice enough to rebook us for another race at Charlotte Motor Speedway since the previous one ran less than smoothly.

Zip6Racing had a good bit of work to do in preparation for the event, but it was an order of magnitude less than for the previous event.  The car had a few issues at the last race, and we wanted to fix those as well as make a few improvements.  A portion of the list:

Flush engine/radiator
Diagnose charging system
Trace MAF issue
Remount bumper
Plug header hole
Fix melted wire loom
Put pins in window net bar
Fix hole/replace tire
Check front brakes
Check rear brakes
investigate low oil pressure
fix camera system
fabricate headlight covers
better temp gauge
Head lights
Mount side windows
Replace rear window
Adjust pass. side windshield wiper
fix cylinder head temp sensor
check compression

The intermittent miss seemed to go away once we soldered in a new connector for the mass air flow sensor along with putting a jumper in the cylinder head temp sensor harness.  With the engine running better, that left us with 2 main things to worry over.

1) We had a tire that somehow suffered a puncture at the very end of the last race (possibly when loading it on the trailer).  We patched and plugged it, and it seemed to hold air.  We would have preferred to replace it, but every retailer seemed to have this tire in our size on backorder.  So we were crossing our fingers we wouldn't have an issue with the plugged tire.

2) Our venerable vg30 engine, as tough as it is, had been through a lot.  When we changed the oil, it looked ok, but we noticed it was smoking at good bit at idle.  A compression test confirmed our suspicions:
Compression test - not so good
Nissan's min for this engine is 128 psi.  We barely made that on the #3 cylinder.  Nissan also specs a max differential between cylinders of 14 psi.  We were nowhere close to meeting that.  From our inspection of the engine last year, we had
cyl #1 200psi
cyl #2 165psi
cyl #3 187psi
cyl #4 170psi
cyl #5 200psi
cyl #6 185psi
so even then we were flunking the max differential requirement.  And as you can see, the numbers had fallen dramatically after Race #1.  The engine was not healthy.  Our spare engine was in Columbia SC, and we really didn't want to go through the trouble of retrieving and installing it.  So... engine health was a worry.

We actually installed plexiglass in the rear hatch frame twice.  The first time, it looked cloudy, and it was removed only to discover an additional layer of peel-off film stuck to it.  Oops.  We really wanted to try and make the car more aerodynamic, as our top speed in the last CMS event wasn't competitive.  The combination of
- running without a hood
- no headlight covers
- no quarter panel windows
- no rear hatch
was in theory really killing our top end.

On Friday, the day when we needed to get the car through tech/safety inspection, we were a few minutes later than planned in getting the car on the trailer and getting our gear loaded, but it was nothing like the exhausting, nerve-wracking thrash before the last race.

We had a bit of a hiccup once we got to the track and realized the race car's brake lights weren't working.  We had packed several totes and boxes of parts into the car for transport to the track, and our assumption was a wiring harness was damaged by doing that.  Sure enough, one of the guys found a ground that had ripped out, and we quickly patched it up.  We had ordered a new CHTS plug, and it was scheduled to land at the local Nissan dealership at 11am.  While one of the guys went to pick it up, a few of us worked on spacing the new headlight covers upward to fit closer to flush with the hood.

The line for tech inspection was fairly short, but it still seemed to take awhile.  With no real surprises or disagreements, we made it through tech and spent a few minutes checking the fit of a spare tire and looking over the car one last time.  With little left that we could do, we all headed home to get some sleep for a 6:30am driver's meeting and a 7:00am race start time.

Ready to race and lookin' better than ever!
To be continued...