Coming back from my second fsae competition in fsae west it looks to me that most of the top teams are competitive exotic FSAE cars rather than a prototype weekend autocross racer. Being on an upper mid range team in west (15th place in 2008, 11th place in 2009) I may be slightly bias.

It makes sense that to win this competition, being competitive in the dynamic events is the priority since that is where all the points are. Hence the use of rare materials, and custom parts.

However, the static events levels out the playing field, and enforce teams to make a prototype weekend autocross racer rather than a highly unfeasible exotic small scale formula car.

One thing that does not make sense is when I walk down the design semi-final garage being flooded with monocoques, custom diffs, custom calipers, paddle shifters, one piece machined uprights, and carbon this carbon that. It seems to me that design judges no longer respect old school simplicity and engineering practicality.

Im not saying that monocoques and exotic materials are not suitable for a weekend autocross racer at all. I’m just saying that as of today, composite technology has not reached the level where it’s feasible to do so. If I was a weekend autocross racer I would rather buy a simple, reliable, and serviceable steel chassis race car with an old school shift lever that comes in a reasonable price.

And if I was an investor I will choose a design that could be easily manufactured in a simple shop with simple tools, and run as many purchased stock parts as possible.

If there are any design judges reading this, please comment.

As far as I can tell, after 6 years of watching this series of events, the weekend racer concept has never been a serious design consideration. The idea of a car so fragile that it cant pass the brake test( sorry OSU, but you werent the first and probable wont be the last) is the opposite end of that spectrum. A car that can finish this event and then race the next weekend is what I would be interested in as a customer. Cars that cant run 20 laps in a row either havent been tested enough or havent been engineered to survive. Some of the "exotic " material is needed in some cases to have that reliablity and although it is more expensive, it is state of the current art of road racing. I spoke with a design judge from a Formula car manufacturer at FSAE West 2007 about tube frame cars and he couldnt think of any reason to build one without a spec design rule. Speaking of the reliability factor, having watched Kansas redesign their way into a solid, competitive team was mostly about making the car stronger, stiffer, and working on the little details that keep it running. This paid off with a string of 8 competitions where they finished all the events. The old racer adage that to finish first, first you must finish is true and how you win FSAE titles. Another indicator for KU is the JMS06 car that was finished early enough to test for about a month prior to Detroit, ran at Fontana, ran at UTA weekend in Texas, ran SCCA divisionals, Nationals and many, many weekend events usually with 2- 3 drivers since. It has had some DNFs but has survived and thrived in the Weekend Racer mode since its construction. It is now the test car for KU wings and aero testing and it possible the fastest car on the campus. (KU tries to keep them all available). How many other teams can say that. UTA, OU, MU S&T, Maryland I know about, but east and west coast teams dont seem to show up for solo events. Isnt that what the cars were designed for. I would like to see more teams at local events and at Nationals. If racing improves the breed then bring your cars out and make them better.

I'm often frustrated by comments such as those that you've made. This isn't specifically aimed at you, but what you say echoes a lot of what I hear on these forums and from some teams and judges at comp, and while I agree with some of the points I think there is a belief that just because something didn't exist 20 or 30 years ago or that Dad didn't teach you how to do it in your garage, that it's complex and exotic and not suitable for an amateur racer.

The monocoque is a prime example here - since most amateur level, purpose built race cars have had space frames for the last 50 years (or more?), people look at a monocoque as a terrifying piece of new technology that should be left to F1 teams. So what are the downsides? The labour required for an experienced composite technician to lay up a monocoque using pre-cut fabric (which it would be if you were doing more than 4 or 5 - same as steel tubes would probably be laser cut and scalloped for a space frame), would probably amount to 20 to 30 hours, with another 5 or so on bagging and autoclave prep. The labour would be cheaper because the required skill level is much lower than a professional welder. The materials cost is much, much lower than most people seem to think it is, probably around $1500-2500US for 25m^2 of carbon + 8m^2 of glue film and 4m^2 of honeycomb core. And don't forget that once the monocoque is done there's usually little to no bodywork to manufacture. So your body and frame might cost somewhere around $5-7K US, which I would imagine isn't a great deal more than a space frame and body work built to a similar standard (maybe $3-5K? Don't have as good an idea of time or materials cost for space frames).

When I look at a space frame I see complexity - multiple tubes intersecting at a node requiring scalloping to a high accuracy, jigging and fixturing to locate all the aforementioned tubes, welding materials of considerably different thickness, welding at difficult angles with difficult access, post-production heat treating to relieve stresses, and I'm sure there's more intricacies that I don't know about. To an experienced spaceframe builder I'm sure that stuff is all easy - to me it sounds like more work than a monocoque . The biggest cost in making a monocoque is really the tooling to do so - plugs and moulds are usually more expensive than the final part, but as the cost can be split across a lot of parts it reduces this part considerably.

The argument people make about repairing damage being difficult is somewhat valid, but boaties have been fixing fibreglass hulls themselves for decades, it's just a matter of learning the requisite skills and understanding the process. For major repairs a monocoque would need to be returned to the mould, but the same goes for major repairs on a spaceframe needing to be re-jigged and heat treated.

As far as custom one-off parts goes - if these were being produced at a rate of 1000 a year, those one-off parts would no longer be one offs, and would probably cost a similar amount to other "off the shelf" alternatives. The difference is that one way the manufacturer is making the profit, the other the profit goes to the generic part manufacturer.

I think in this competition there are advantages whichever way you go: if you use off the shelf parts and stick to manufacturing processes and materials that you know then the car should take less time to build and therefore the added testing time will allow you to extract more performance from your design. If you use more custom parts and delve into modern manufacturing techniques and materials you can probably build a lighter, stiffer, less compromised car, but possibly at the expense of testing time. If you can adequately justify your decision to go either way (or somewhere in the middle) then you should do well in design, and if your justification was sound then you should do well in the dynamic events too. If you do poorly then maybe you need to re-evaluate because it probably suggests the benefits you expected to get from the path you chose were overestimated or just plain wrong

Manufacturability is worth a percentage of the 150 points designated to design. Since no team comes with a true go kart, teams rarely get the max points alloted for manufacturability, but no team comes with a design that is unmanufacturable either, so no one gets zero points. There are no points awarded for cost in design. Once teams make it to finals, manufacturability is rarely considered as to which team wins design. Team knowledge carries more weight in finals.

Also, not pointed towards you but I saw considerable backlash on the competition thread. No judge feels comfortable penalizing a team who was able to build an F1 car with their F1 budget, nor inflating a teams score that did the best they could with a meager budget but whose car is just not as good. This isn't the US government, this is racing.

I think students spend a lot of time trying to figure the judges out when it's really very simple. There is no such thing as brownie points, judges just want to see well thought out systems engineered cars that have been optimized for all 'and only' the applicable variables, and students that truly understand what they've built. Judges don't speak in the language of excuses; judges like data points, not sales points. There's difference between selling your design, and explaining your design.

These types of posts are always interesting. Even within my team when I was still in Uni, we had this discusion. Where we fell at the time was that composite monocoques were outside of our means and unreasonable to be repaired. Obviously the current team has taken a different direction as witnessed by their first year monocoque. And I think they have succesfully shown that it is possible to repair a composite carbon structure that has been compromised.

Also, both Boeing and Airbus are now widely using composite strucutres in areas that are prone to flight damage. While the 787 has not yet flown, several current aircraft use composites in the external structures of the aircraft. This has neccesitated the development of field repair kits for the composites just as they have repair kits for the Aluminum structure. The same can be done for a race car chassis if you understand your potential modes of failure and the materials you are working with.

On the topic of buy vs. build it is a touchy situation even in the real world. It is one of the most common things that comes up where I work. The reality of it in this type of situation is that you need to balance it. A customer will almost always want a part to be off the shelf. While for the person manufacturing the equipment using a bespoke part can often be better. A bespoke part when bought in the quantities dealt with at my company often falls on the edge of cheaper or more expensive than off the shelf. If everything I made was in the quantity of 1000 as opposed to 25-200 then bespoke parts would usually break even or be cheaper to make than off the shelf parts are to buy. In that situation a manufacturer is better off making bespoke parts both because it is cheaper during the initial manufacture, but also because they get to sell spare parts. The downside is the customer now has to maintain spares if the bespoke part is one that is prone to failure.

Here's how I think of it:

Throw the whole "weekend autocross" mindset out. Throw it away. It's garbage.

That may have been the original intent of the rules. It still says it in the rules. It's not true.

No team that has won design since I've been around has had anything close to a weekend autocross vehicle.

The F1 teams will continue to win, and shouldn't they? They manage to get the best budget, best technology, implement it well, and have fast cars (or sometimes just pro drivers). Sound like real winners to me.

Thanks a lot for the comments guys, this has straighten out some things in my head. However my question really comes down to
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Can and team with a budget of $50 000, 300hrs of machining time, and no access to composite facilities win design finals??
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From what I can see in the short two years of my FSAE experience, high budget teams that run an “exotic” car has greatly improved and has gotten far more "exotic". While the low budget teams that run the traditional spaceframe and hand shifter havent moved at all. The gap between the teams is just getting larger and larger.

What bugs me is not cause the high budget team are not getting punished for not following the "weekend autocross racer" theme, but is due to the fact that the low budget team who is only capable of making a "weekend autocross racer" is not rewarded for their efforts.

AA

Stuttgart did incredibly well last year, including numerous design wins, with a car that didn't have anything that should really be out of reach of most teams - they had a pneumatic shifter, some nice cast aluminium uprights, and carbon wheels; but I doubt the results would've been much different without those items.

By the way, $50,000USD is considerably more than our budget, our total sponsored machining time (including work done by the Engineering Dept machine shop) would be under 300hrs, and last year we still managed to build a car which features a number of things that are above the basics, and pay the costs of competing overseas (no competition in NZ!), and the only extra advantage we have is a sponsor who supplies us free autoclave time (but in the past we used to make all our composite parts with wet layups or resin infusion). We came second in design in Australia last year (to Stuttgart), so I don't think you need a massive budget to succeed in design. I'm not sure if we would have done as well in a bigger competition, but I think it's a good start.

My theory is this: well organised teams are probably able to make a stronger push for sponsors, and therefore get more money. Not coincidentally, these well organised teams also have a logical design approach that entails putting a lot of analysis into their designs and their decision making processes(which is a good start to doing well in design). Their organisation extends to being prepared for static events (which is the big secret - we went from 12th to 2nd in design at Aus in 1 year by being considerably better prepared), which means they do well in design.

I know what it's like to despair about perceived disadvantages in the design event, but if you can create a sound justification for your designs to yourself then there's a very good chance you can convince the judges too. How many months out from the competition do you do you first practice for design event? And on how many separate occasions do you do practice presentations and simulated events? If the answer to either of those questions is less than 4 or 5 then I'd suggest rethinking your strategy

You're designing a car to score the most points at a FSAE competition. Pure and simple. Going along with Hector... forget the weekend autocross thing.

Having seen 5 years of competitions and observed a number of teams... a lot really comes down to being the least shitty. It's all relative. It's not that judges don't like simple practical things. In 2002 or 2003, some relatively simple cars were probably the least poorly designed ("best") of the lot. Many teams have moved beyond that.

'Exotic' does not win design. Well-engineered does. I used to think fancy crap would score well in design, but it doesn't. Engineering merit and data are where it's at. That can be a simple solution or a really wild one. If someone uses flexure suspension joints, or built their own shocks.. or even just use a trick off-the-shelf shock... big deal. Who cares, unless there's a good reason behind it. Show me why damper curve X is required for your car, in a transient vehicle model (or whatever you want to use to justify it). Show me the design alternatives, and show me which one best met your requirement. Show me the data that shows it performed as expected. That's what judges want to see.

With regard to monocoques though, there is a bit more to it than just the build cost. Sure you can build something out of carbon for relatively cheap. But, as was said the tooling cost is high. This is FSAE, so it is a one-off. The engineering cost is also probably much higher than a tube frame... between analysis required for accurate analysis and design with varying ply orientations, and time behind the computer. I wish this was also included in the cost event, though it would be impossible to track.

I really don't think you need a fancy car to win the competition. Even the real trick 'super' teams these days that perform really well.. there's still plenty of untapped room above them that's up for grabs by anyone.

So to answer your most recent question Alvin, "Can and team with a budget of $50 000, 300hrs of machining time, and no access to composite facilities win design finals??" YES. Absolutely. That's actually quite a bit of cash.. a shitload really.. and a lot of machine time. I machined the majority of the parts on the car by a fair margin and only came to ~180 hours, including programming and setup where applicable. That includes custom wheel centers, billet uprights, billet 4130 hubs, etc. And I coulda been going faster

Comes down to the people. I'd bet that a team of 6 alums could do it and crush the static and dynamic events. I even know who I'd pick. Wouldn't be fair, but again that's the point that it comes down to the people and the knowledge.

Of course, that's just my opinion.

$50,000 is a high budget team. Structural composites certainly aren't neccesary. From the picturse I saw, RIT was a steel frame car. Also, from the limited information that I have, the steel frame car that OSU ran last year was only 60 lbs heavier than their carbon car this year. That weight difference can be entirely contributed to the engine change, last year they were running a 4cyl and this year a single. I also don't think that their physical perfromance is all that different between the two cars.

The big difference in their performance was an increase in knowledge and preparation. Every year I was involved with the team and the 3 years since I graduated the knowldege and organization has generally increased on the team. Early in my involvement there was some thoughts amongst our team that it was what you had that mattered. At the '04 competition it became blatantly apparent that how you present your car and how well you know it is far more important. We made a huge step in '05 and they have continued to build on it since then. A car with design compromises but with lots of good reasoning and understanding will do better in design than a perfectly designed car that is not understood. In order to do well in design you need to bring both to the table and present it in a coherent cohesive manner so that the judges understand that you know what you are doing.

Regarding the "weekend autocross racer", the reason FSAE cars don't look like a typical autocross car is because a typical autocross car isn't made by people with access to equipment typical of what a manufacturer might have. Most FSAE cars are built by groups that have access to equipment typical of what a manufacturer making 1000 of these per year might have. Look at the manufacturer produced D sports racers for an idea of what might happen if a manufacturer actually produced turnkey autocross cars.

Well. Just to be annoying and point something out. This isn't what I suppose would be called a "typical" weekend racer, but it comes very close and a very large amount of people are using it just for that reason.

Stohr WF1

And actually, if you want the F1000 car, its cheaper. The WF1 is $59000 for a rolling chassis. The F1000 is $39900. The point is, yeah, its not built in a garage but it is the current state of the art and if you want a weekend racer but didn't want to throw it together in your garage you'd buy something like this or similar. And these are fairly similar to a High Budget FSAE car. This is your goal. You want to build a easy- to- manufacture, well designed weekend racer using the current state of the art. Carbon is that. CNC aluminum is that. Yeah, you can't really make that in your garage with your 110 volt welder and 2 axis bridgeport mill. But you can't win with that garage built car either and you sure as hell couldn't/ wouldn't do the testing and data acquisition required to win if your weren't willing to send stuff out for CNC'ing and carbon manufacturing.

I think its just welcome to 2009. The age of tinkering in a home garage is over. Gotta send stuff out to the guys who have the machinery you can't afford.

This is the first really good thread I've seen in a while, good job guys.

The teams that win competitions act like racing teams with a driver training program, NOT like weekend autocross car manufacturers. There is a reason for that. They succeed at achieving every possible advantage over other teams, whether that comes in the form of weight, driver talent, money, stiffness, power, etc.

If you are building a car to make 1000 of each year, just give up on trying to win. There's nothing wrong with that goal, but it will not win you the competition.

Regarding winning design, I disagree with exFSAE. Maybe in 2003 you could win design with a simple car, but the head design judge at MIS this year said in the design review that ETS had the car the judges would want to buy, but they gave 1st place to TUG because it's fancier. This is a clear indication that teams need to push the limit in terms of technology to succeed.

When giving design feedback, our judge told us to 'have an active diff' (this is a direct quote) or make our own ECU (we run the most advanced ECU in the series that no student could ever beat). From this experience, it became clear to me that the judges are increasingly looking for fancy shit rather than thorough engineering. Frankly, it's pathetic.

And while we're on the subject, let's not ignore the fact that many teams the thread maker would call 'exotics' are mainly composed of 22-26 yr olds who take off from classes to work on FSAE. When most everyone is an undergrad 18-22 yr old who has to balance school and racing, it's a slap in the face to see what are essentially young professionals beating us in the design event and on track. I can assure you that the 25 yr olds who were on my team are now working on real race cars that win LeMans, Cup, etc. They are NOT beating up on kids who are just learning what engineering is. And kudos to teams like UMR and RIT who keep these guys honest and show what a well integrated, well tested undergrad-built car can do.

This message has been edited. Last edited by: flavorPacket,

I don't really understand people complainig that judges would only recommend the most tricky carbon cars.
For example the discussion about monocoques. I can't see if judges prefer them or not. Last year several design events were won by space frame cars and several by monocoque cars. As said above it's about to justify your design. A well engineered space frame will always be better than a bad monocoque.
Same for all the other fancy stuff. If you just have it but you don't understand it, you won't get any credit by the judges.
And telling a judge that your opinion is that a fancy solution is too expensive will count as a good point, if you really thought it through.
I also want to say, that it is possible to build a car that is competitive while reliable enough to run several weekends in a row. Our old cars are all still running. Of course sometimes something has to be repaired but that's normal also for a normal autocross racer.
Reliabilty is the most important point for both the autocross racer and for a competitive FSAE car. I think you will always be better up if you build a simple car and finish it early than building a fancy car and don't manage to finish it in time. So I think that winning competitions and building cars suitable for amateur autocross racers can definitely go together.

quote:

Originally posted by Hector:
No team that has won design since I've been around has had anything close to a weekend autocross vehicle.

Our 2007 car won design. We regularly use it for SCCA events, and it is competitive, light, simple, and easy.

Our 2006 car has gotten second at SCCA Nats, and is still running in competition trim, with the only changes being oil and more fuel.

Our 2008 car (Third in West) Is still running as it was in competition, and has been to numerous SCCA events.

2009 was also designed for the weekend autocross - because we like to drive it there, and if the judges don't like that we don't particularly care. We design it for a weekend autocrosser, and whether or not we win design, as long as we've benefited from the competition in the way that we see fit, then we're satisfied. Just as the judges look for certain criteria in a car for them to place more weight on it's design, we look for certain criteria in competition that we care about. If it doesn't fit our design plan and team goals, we'll just skip that part. So long as we're rules compliant, we'd much rather make a car that we would teach us engineering and have fun driving than would win design.

I think my response was mis-understood, although I can't seem to see how it was. I didn't say judges prefer simple designs. What I was getting at is they don't care how complicated the car is, they only car about how fast the car is. If a seemingly simple design creates a super fast car, they'll know.

I think technology and doing well in design don't correlate to each other but both correlate to the best teams. A simple example is to give the TU graz car to a few high school kids and see if they make secondary. You could also imagine an opposite scenario where a bunch of alumni could create a 'simple' car, but be able to talk at the same level as the judges and make it to semis if not finals.

And in just 2007 didn't Texas A&M win with a 'simple' tube frame car with minimal bling? Doesn't mean it could still happen, but that's a lot more recent then 2003.

quote:

Originally posted by VFR750R:
A simple example is to give the TU graz car to a few high school kids and see if they make secondary. You could also imagine an opposite scenario where a bunch of alumni could create a 'simple' car, but be able to talk at the same level as the judges and make it to semis if not finals.

Agree 100%. The latter would be kinda fun, though completely unfair and pointless.

Thanks a lot for the comment guys, I never thought that I would receive this many comments for this thread. I just want to comment that the weekend autocross racer is not only reliable easy to maintain. (As shown by all the evidence of the running old cars teams are running etc etc). The number 1 priority is the cost, money is everything.

Everyone knows there is a BS cost report cost for the car, and a true cost that is embedded within our heart. If there is a simple spaceframe car that has 90% the performance of a fancy monocoque that come in at 25% of its price, I think the simple spaceframe car is by FAR FAR the better "weekend autocross racer". (Just a note I don't think 25% of the cost is exaggerated).

So far I have gotten the following conclusion

***** “Prototype Weekend Autocross Racer” theme is unofficially scrapped by both the teams AND static event judges. We are designing/building a car to compete in the FSAE competition.

***** There would never ever, be an underdog in the design event. Maybe in the past, but not anymore. Teams with limited budget, facilities and experience (garage cars) would never ever win design.

Like I said before, I belong to a team that is run by only undergrads doing full course load and incapable of building an “exotic” car at the moment. Therefore I am most likely bias towards the less “exotic” cars.

AA

quote:

***** There would never ever, be an underdog in the design event. Maybe in the past, but not anymore. Teams with limited budget, facilities and experience (garage cars) would never ever win design.

What are you defining as an underdog? A team that builds a spaceframe car without a lot of bell and whistles or a team that doesn't fully understand their car?

Teams with relatively simple cars have made it to design finals in the past 3-4 years. Just look at RIT, Penn State, and even Stuttgart. Outside of the welded ti suspension bits on the PSU car,(which really aren't an impossibility for another team to do, and might not even be a good idea) there really isn't anything particularly "fancy" about those cars.

Granted there's a fair amount of luck in which design judges you pull, but by and large the teams that do well in design are the teams that do a good job of managing their program and defending their design decisions. The teams that don't do well in design usually either have something glaringly wrong with their car or don't spend enough time preparing for the static events.

quote:

***** There would never ever, be an underdog in the design event. Maybe in the past, but not anymore. Teams with limited budget, facilities and experience (garage cars) would never ever win design.

Opposite. I feel entirely confident I could start a team with some friends, at a community college, and make it to design semis, design finals, or just outright win.. with the first car.. using no Ti, and no carbon. Probably be a 2 year project, admittedly.

It's all about KNOWLEDGE, and proper use of real engineering design, application, and analysis. Admittedly if we started a team of alums from pro motorsport they all have specialized knowledge, but consider that "industry mentoring" in your case.

Racecar engineering is really NOT that trick, once you figure out how to break it down. YOUR team could certainly win design. You've just got to establish a good knowledge retention program so you can continue to build on past experience every year... and a good project timeline and budget management system to include some level of year-round design and testing.

exFSAE, I have to disagree. Would your simple car kick ass? Without a doubt. But I doubt it would win design.

My alumni friends and I have discussed this at length. Simply reducing the amount of bullshit you deal with, let alone increasing the quality of the car, would make any team much faster.

BUT, the judges are starting to give points more for what you do, than for how you do it. If you don't do something really impressive, you won't win design. Every car in finals has something to really impress the judges, whether it's TUG's chassis and motor, UAS's motor, ETS's chassis and ergo, PSU's weight. I'd bet you make semifinals, though.