Even more challenges

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The drive thankfully was boring – that’s how I like them.  15 hours the first day, then a brief stop in a motel, then 8 hours the second day starting at 4 am and arriving at noon, directly at Pikes Peak International Raceway for a brief shakedown.  Some nice views of the Mountain on the way. It is cold up there (29 degrees forecast for the morning) but down in Colorado Springs it’s hot – feels like 90+.

We arrive, unload, and Jonathan goes out for a few laps of the parking lot to see how the car behaves.  Things that are new are bodywork, wheels/tires (including different size in the back) and a few minor tweaks to systems.

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He’s able to hit some pretty impressive speeds in that small space as the videos attest:

Everything seems to be working well.  Then Rodney goes out for a bit to get a feel for the car.  He is surprised how well it puts the power down.  Watching Jonathan’s videos you’d think the tires want to spin, but he’s actually using quite a bit of skill to get the car to do that.  Normally, you punch it and it just goes.

Then Rodney goes out again and quickly comes in – the car is pulling hard to the right under braking.  I set off to retrieve his replacement credentials at the hillclimb office while Chris and Jay set about figuring out what’s wrong.  After getting the paperwork I stop by an auto parts store and get a replacement brake bleeding kit that we seem to have left out of the trailer.  Then I get a call from Jay – bad news, we sheared off a suspension bolt.  We do have replacements but getting the old one out will take a bolt removal kit and a tap set to chase the threads.  Back to the store then back to the Raceway.

Things are not going well.  The area where the broken bolt is located is very tight and it’s hard to get the drill in there. So the hole for bolt remover got drilled off-center.  The bolt has red Loctite on it so it’s unlikely it will come out with small diameter extractor.  We definitely don’t want to snap one of those off in the chassis, that would be a showstopper.  So we try drilling a bigger hole.  The drill snaps, fortunately not in the hole.  Progressively bigger drills enlarge the hole but get perilously close to the threads on one side.  Extractors are not working.  It is now around 6pm and the track staff are wondering how long we’re planning on staying.  At the moment, we’re dead in the water and have no possible way of getting the car ready for tomorrow 4am on the Mountain.

For those curious, the bolt sheared off at thread root (even though the shear plane load is across the solid shank some 1/4″ away).  The fracture shows a stress riser at a point which is older than the rest of the break, from which the failure propagated.  It seems it took numerous cycles to finally make the part fail – it’s the same bolt that was in there for last year’s race and all the testing since.  While it looks like a defective bolt issue, we do have a way of reinforcing the area just the same.  It will get done when we get back to Portland but it doesn’t help us now.

In the meantime, we are told that Paul Dallenbach and his crew are working in their shop a few hundred feet away to get his car ready, and they have a full set of tools. I think about how that might help us.  If I fashioned a steel pilot bushing that is 3/8″ OD and 11/32″ ID, I could use it to guide a drill or endmill to get rid of the old bolt while saving the threads.  A trip to their shop yields a piece of 3/8″ OD steel tube about an inch long, but it would have to be drilled out.  They help me put it in their lathe and I make the bushing.

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We try it with a 11/32″ drill first which doesn’t work.  Borrowing a 5/16″ endmill and carefully aligning the drill does get the job done.  The old bolt is gone, we can see undamaged threads and a couple passes with a tap clean them right up.  By now it’s 8pm and we have to load up and get going.  One great thing about this race is that it’s still a community – Paul is our competitor in the Unlimited class but he and his crew, as well as the staff at PPIR, have really come through to help us.  We literally would not be running tomorrow without them.

Some pictures of the car in the setting sun – it does look good in this two-tone primer grey. We’re still planning to paint it orange for the race, but good to know it wears dark colors well because those are my preference.

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We pull into the rental house in the dark.  It is 11 pm as I write this, and we’re up again in 4 hours for testing.  Tomorrow is another day. In the meantime Tristan is back in Portland working feverishly to get the D1PPS ready.

 

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