In one corner of the room sits a polished 2006 Porsche Cayman S resting on hydraulic lifts. In the other corner, senior Jonathan Granstaff wears earplugs and safety glasses as he stands over a buzz saw cutting support ribs out of aluminum. Granstaff has spentnearly 90 hours here this past semester.
Granstaff worked to build a rear spoiler. He is in his second year in the auto program at East. He has always enjoyed reading about cars and would consider working on them as a job if the opportunity arose. His idea to design and build a spoiler was something entirely new to East auto teacher Brian Gay.
“[No projects] have been aerodynamic like this,” Gay said. “This was the first that needed to be designed on [Computer Aided Design]. Usually they are more physically challenging, but this was more of a design problem. He almost could have decided on building an airplane body and had similar problems, it just so happens that we put it on a race car.”
Granstaff built the rear spoiler to go on a Porsche Cayman S owned by a friend ofGay. He built it to help increase the traction of the car. The spoiler does this by causing air to flow over the top of the car. It then pushes down on the spoiler, which pushes the car into the track on curves, increasing speeds.
“On race cars, in general they have spoilers and just other aerodynamic parts that help them out on the racetrack to give them grip,” Granstaff said. “That is what you’re going for, as much grip as you can get with as little weight added so you can go into turns faster.”
The car started off as a standard Porsche Cayman S worth approximately $60,000. Last year, Gay had his beginning auto tech class strip the Porsche and rebuild it into a racing Porsche worthy of use in the interseries races- – an American car series with car designs based off of historic racing Porsches. After two semesters of work from the auto tech class, the car’s value has risen to about $80,000.
“[The owner] would be allowed to use the car if he joined the interseries, although they would have to make a couple little changes,” Gay said. “We built the car up with the idea that if he decides to go racing he has the set up all the modifications we do are good for that.”
Gay suggested that Granstaff expand off of what the auto tech class did last year when they changed the Porsche’s transmission, suspension and overhauled the interior. Granstaff looked at Porsche interseries cars and their rear spoilers; this gave himthe idea to design and build one.
“I went into CAD and drew it out,” Granstaff said. “It took about a week to figure out how to make it structurally sound because you don’t want it to fall off. Then I printed it off to scale on paper so I could print off all the pieces.”
Granstaff started off by cutting out all of the ribs from aluminum using a jewelry saw. After all of the main pieces cut out, he riveted them together with the help of Gay. He used about 300 rivets in total to attach the ribs to each other and to a piece of L channel aluminum, a bent piece of metal used for strength. The final step was to wrap the entire spoiler in a thin sheet of aluminum.
One of the main problems that Granstaff ran into while building the spoiler was ensuring the structural stability. With speeds approaching 175 mph and nearly 200 pounds of down force being applied at the most critical angle, the wing had to be built stiffer than expected.
“We didn’t really account for having to put in the L channel aluminum lining the entire wing,” Granstaff said. “He just told me we needed ribs but it turned out we also needed a lot of other support.”
According to Gay, all of the hard work payed off as he was able to take out the Porsche for a day a couple of weeks ago.
“With Jonathans’ spoiler it was just a little bit slower on the straight away,” Gay said. “But it was much more stable in the corners. On a racetrack, you are happy to give away a bit of straight away speed to make it up in all of the corners and it does a good job of that.”
Granstaff said it is also a possible career path. Next year he is attending the University of Kansas and is planning on majoring in mechanical engineering.
“I really enjoy doing stuff like that so if there is an opportunity I definitely will pursue it,” Granstaff said. “I like working with my hands and I love CAD, I don’t know what I’m planning on doing with my degree but I would like it to have something to do with cars.”
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