Thursday, July 12, 2012

Lotus Cup Laguna Seca 2012



What a weekend! This was the first time at Laguna for Glen, and he once again proved to be a quick study, learning the track quickly and accurately during our Saturday afternoon practice sessions. This proved to be instrumental to our success, as we lost the last portion of the final practice session on Saturday and the entire first session on Sunday, due to a mechanical issue with the Art Car’s engine. Racing has an amazing ability to bring any weakness in preparation and equipment to the surface, which is what makes competition valuable for us as a learning experience. As we all know, sometimes learning experiences are not easy!

During Saturday’s last session Glen had been turning laps in the mid to high 1:40’s, still learning the track. On the 7th lap, he had an issue entering the corkscrew which ended in a spin. After he got going again, the car suddenly lost power. He brought the car immediately to the hot pits, and it was apparent the car was randomly misfiring. The decision was made to abandon the rest of the session and get the car back to the truck for a closer inspection.

With the car back in the pits, imagine our surprise when we found the entire intake and blower assembly loose from the cylinder head! Working back through the sequence of events leading up to the race, it became apparent what happened. We had recently installed an air temperature sensor in the intake manifold, for measuring the temperature of the intake charge. When the manifold was re-installed the top two fasteners (of 5 total holding the intake / blower assembly to the cylinder head) were incorrectly torqued, leaving the bottom three studs highly loaded from the belt tension and eventually shearing them all off!


Picture Showing Top Fasteners, which loosened up, placing additional stress on the lower fasteners

 

Picture Showing Center, Lower, Stud on the Intake, One of the Three which were damaged at Laguna

With the problem identified, we set out to remove the components required to access the broken fasteners, still at that point not certain they could be extracted with the engine in place. With the blower, intake manifold, fuel rail and injectors, plus throttle body out of the car, the guys gained enough access to go to work.

Armed with a drill motor, center punches, hammer, and borrowed left hand drill bits (THANKS TO ROBB BANNANO!) we set about extracting the broken studs. By 10 p.m., all were out with no damage to the cylinder head, and the engine was ready for re-assembly.

Sunday morning, we arrived early and thanks to the generous help of Rob Dietsch of Dietsch Werks in San Jose,( www.dietschwerks.com, THANK YOU ROB!!!) we had new studs and flange nuts to replace the ones we lost on Saturday. Working through the first practice session we were able to get the Art Car re-assembled and back to her former self!

Moral of the story: Always use the proper torque specification on any fasteners.

After a quick run test in the pits using the data system to verify all engine parameters were in spec, we were ready to go for the second and final practice session. Glen turned consecutive mid 1:38’s on the 4th and 5th laps on worn tires, and the car was working well.

The next session was time-attack qualifying, and with a fresh set of tires Glen and the Art Car ripped off a 1:36:62 on the second flying lap, a truly impressive performance.

In the race, after an epic battle with Kevin, Glen managed to win the Open Class, and take Third overall, with only Andy and Robb in 211’s ahead. This was the best possible way to end our weekend, and certainly Glen’s performance on Sunday made our aching muscles from Saturday night well worth it!

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