I know people were interested in seeing the build on our last car, so I figured some more might be interested in this car. Last year was technically our first year, so this car should be much improved. We learned a lot while building and tuning the last one.

For those who don't know, FSAE is a student engineering competition where students design and build a racecar from scratch. The pretense is that the car is supposed to be marketable to the weekend AXer. The rules are pretty wide open; besides safety rules, the main points are that engines have restrictors and are limited in size to 610cc's, the car must have 4 wheels, and is limited to a minimum wheelbase. The goal of the competition is understanding the engineering behind the components and systems; all parts are supposed to be student designed from the suspension kinematics to the frame to the suspension components. There are competitions all over the world (Michigan, Virginia, California, Germany, etc). The main competition is in Michigan; we brought a car last year and are planning on doing so again this May. At competition teams participate in design and marketing presentations and dymanic events such as the skidpad, AX, and a 22km endurance.

The first picture is of last year's car running in the Endurance in Michigan. Following that are pictures of the frame construction, homemade dyno, and some suspension design pieces. Most of the pictures I have are of frame components because I am in charge of chassis fabrication, but I'll try to get some more suspension/engine pictures up.

Competition last year:

Tilt Table
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Endurance?
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The frame is constructed from low carbon steel (CrMo really doesn't make sense in this instance since we are shooting for stuffness, not ultimate strength). This frame weighs approximately 65lbs, and discounting stiffness contributions from the motor, FEA results project a torsional stiffness of 2500lb/degree of twist when loaded at the wheel. I can't fid the FEA screenshots, but when I do I'll post some up. The pictures show a tacked frame, but welding should be finished by this Saturday. In general it is mostly MIG welded, though sections will see the TIG torch.

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As a note, the frame is rather wide because of new cockpit and fuselage rules. They make it a bit harder to keep the weight down and stiffness up, but do allow for more equitable car building. Without those rules in place it was very disadvantageous to have larger drivers.

Lats year we used a Honda CBR600RR motor. We made a mistake with the oil pressure relief valve (no one knew it was removable), and neglected to put a bung to hold it in the custom oil pan. It ended up popping out and the engine ran oil starved for quite a while. Surprisingly, it lasted for a while after that mishap.

In any case, due to cost/availability problems, we decided to make the switch from Honda to Suzuki. Now we are running a GSXR600 motor which are much easier to find locally in the case of emergency and are also significantly less expensive. This motor is being run with an Adaptronic e420c computer. The cool think about this computer is that it has a serial port to plug into our Innovative LC1 O2 controller. It also has a ton of I/O which is very useful for this application. Currently some EE's are working on a wireless transmitter to monitor vitals from track side.

We're still waiting on a few harness pieces, but the motor should be running within the next 1.5 weeks or so. We were able to get our hands on an older Stuska water brake engine dyno and custom-built the engine interface/pump/control valve system. The whole assembly is being run using LabView. One of the team members is on his second career and has 15+ years of tuning experience, so it should be interesting to see what can happen in somewhat professional hands. I only have in progress dyno pictures but you can get the idea.

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cool! keep us posted

I'm not a huge suspension guy, and don't have any built component pictures, but here are some of the drawn components in fabrication now. The goal of this year's suspension design is standardize as many parts as possible to simplify potential mass production of the car (one of the competition's design goals). From our perspective, standardized components are good because we need to make less spares.

The first picture is of the brake rotor design. The rotors weight less and 1lb, and are stainless steel and fully floating. We are using off the shelf Wilwood PS1 calipers as can be seen in the suspension corner assembly.

The next pictures are of the front and rear corners. Yes, the a-arms are made using bonded carbon tubes. The uprights are cast aluminum graciously donated by one of our sponsors, Yankee Castings. The uprights are interchangeable from front to back. As is shown, the brake rotors are inboard. This should allow for easier component changing and also works better with the wheels we have. There is some more, but I'm getting tired of writing so onto the pictures:

We have a sponsorship from Lotus, and used one of their programs as a suspension design tool. Here is an example plot.
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Front/rear corners:
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Upright FEA screenshot:
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Cutaway assembly view:
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That's all for tonight; I've got to get back to tensor calculus.

If anyone has any comments or suggestions I/We'd [the team] would love to hear them.

Hope the heck your car is more reliable than the one that runs aroud down here. Didn't even finish one AX run.

Good luck.

What a great project! Thanks for posting. I wish they had had something like that when I was in school....yeah I know me and Henry Ford way back when. The wheel base looks so short, but I guess it's only because the nose sticks out so far. What is the wt distribution like?
Those carbon fiber locating rods look trick. Are you guys fabricating them yourselves? How?

IIRC the wheelbase is around 60in; its very small. I'll check on that for you though. All of these cars need an impact attenuator on the front and our nose was large because our attenuator was rather long. The old car also had bottom mounted pedals with the master cylinders ahead of the pedals. This adds about 8in to the nose. This year's frame is actually about 12in shorter than the old car's without impact attenuator.

We are fabricating the a-arms and pushrods in house, though we are not actually making the carbon tubes. While we have some of the equipment necessary to make them, we're buying them from a tube supplier. The tubes are then cut on a wetsaw and bonded to the lugged ends. We're making the ends in house unless a gracious sponsor comes out of the woodwork and is willing to machine them. They will probably be one of the most complex pieces to make on the entire car as we only have access to a 3 axis CNC mill and they'll need multiple setups.

On that note, a shameless plug: If anyone here is interested in sponsoring us we're a non-profit student organization which does not receive any official school support and can get you sponsorship packets with details. Even the smallest monetary, labor, or material sponsorships are helpful.



Edit: Talking about the carbon arms, each complete corner assembly weighs a bit under 17lbs including wheel.

Quick story: The old car is entering a car show on Friday and we got it running last night. It sounded good last night and had good oil pressure. Today was a different story. It started off sounding good, and suddenly it threw a rod. Interestingly, the rod is still attached to the crank, but turned towards the transmission and broken into 3 pieces. It also wrecked the cylinder wall, broke into the water jacket, and punched a HUGE hole in the block. All of the oil poured out of the exhaust and lit and we ended up hanging out with the fire department for a while. No pictures as of yet but rest assured that the case is toast. Luckily we have 2 more motors.

On a more positive note, the gas tank is almost done. It's 1.91 gallons and occupies space to the right of the driver, conforming to the frame rails. On the engine front our new ECU just got here today. We upgraded the firmware tonight and did a thorough check to be sure its ok, and we're planning on starting wiring it up on Friday.

Have you thought about the advantage of running the the carbon arms vs. time and cost. You don't really save much weight and the complexity of machining the ends can offset the advantage pretty quickly. Also the carbon tubes you can buy (I'm assuming from McLean Composites, as most teams do) are better suited to tension than compression, so you will need to oversize the tubes vs. your calculations of loads, making the advantage even smaller. Also not sure if you have seen what happens to these tubes with a simple cone hit. I know you shouldn't hit cones, but it happens.

When I was in FSAE we made carbon a-arms with flexures replacing the inboard rod end/sphericals. The were light, and unbelievably strong. Also when they failed they could still carry 70% of the normal load meaning the car doesn't drop to the ground (which would be very bad on a carbon tub). That never happened while driving, but we tested them to destruction in the lab.

The car looks good. Put your time in with the team. It is by far the most fun you will have in college hands down, and you will learn a lot too (probably more than in your classes, or at least learn it sooner then your classmates.)