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Thread: 2015 FSAE Rules

  1. #81
    The Jr. Dragster tires are meant to be used burn-out free because they are attached to Briggs and Stratton engines that have trouble doing a burn-out in the first place and they come in a 8.5" wide model. I don't think they would have a problem finishing endurance, honestly.

    The 8.5" wides are 8" wheels if anyone decides they need to go even smaller.

    Alex and I have had serious conversations about Jr. Dragster tires but never had the funds to buy a set to test.
    Last edited by MCoach; 08-02-2014 at 05:14 PM. Reason: because racecar
    Kettering University Vehicle Dynamics
    Formula SAE 2010 - 2015
    Clean Snowmobile Powertrain 2012 - 2015

    Boogityland 2015 - Present

  2. #82
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    duh, like, evry1 nose go carts arnt legal. like, duuuhhhhh

    I have never really prioritized the acceleration event – rather I always assumed that one point earned in acceleration was worth half of two points earned in Cost. Or maybe that one point in acceleration was worth ten times as much as a tenth of a point in skid pad. Once I had satisfied myself that one point was in fact equal to a point, and that our overall score would not be adjusted because acceleration points have greater awesomeness than presentation points, I just put them all together into an overall event sim to see what concept worked out best over the whole event.

    Some quick observations having skimmed through the above fairly quickly:

    The reward for the Accel Event is in points. Points then sum to an overall score, which determines the overall event winner. The times above are interesting – but I didn’t notice anyone taking the next step to convert them to points. It is then you begin to see whether the changes required to bring about these times are feasible.

    I would love to see a 300hp FSAE car. I would love to see how fast it was along straights. How much faster it would be around corners. How fast it would be under braking. How cheap it would be to run. How cheap it would be to build. How little fuel it would use. I would love to meet the powertrain leader and the traction control programmer. I would love to give the two of them a teacup, and call the teacup “grip limit”, and fill it to within 5mm of a line drawn just below the rim. At the sound of an academic wringing his hands and quietly sobbing the word “sub-optimal” I’d set them the challenge of filling the cup to the line using nothing but:
    a metropolitan firetruck driven by banjo wielding bogans wearing Chev v8 t-shirts, and
    a small bailing bucket with a traction control brochure in it.
    I’d offer the two of them $50 to finish filling the cup to the line, and in plain view but without telling them I’d debit their credit card $25 for every litre of water that was wasted, and every minute spent on the task. Upon completion of the task, I’d get them to write a cost benefit analysis on cost benefit analyses until someone cried the word “futility”.

    It is a constant amusement to me to see the way that the first reaction to Z’s input is one of antagonism - more often than not to identify some detail that is wrong, or difficult, or uncomfortable, or unfashionable, or just plain different – ridicule it – and then dismiss it. It is almost a sport. Z pokes his head up – and the masses quickly rally to shoot him down. Irrespective of his message.

    Quick lads, better shut him up. How can we all agree on what it takes to be novel and creative while this guy keeps throwing up different ideas…

    Now I do not agree with everything he says. But I enjoy hearing it. He challenges me. I learn from the challenge. I look for aspects that I might refute, and I look for gems that might help me.

    Z and I chatted about acceleration event at Oz comp last year. He mentioned the concept of the 100% rear axle load acceleration vehicle. That was enough for me. I took the idea home. I wrote a simulation. I found that raising a c of g 30cm gave the same gain as 15 extra kW for the vehicle spec I analysed. I started thinking of ways to design a device that could jack up 30cm through reversible brackets, etc. I didn’t think of FSAE car, I thought of “self propelled jacking seat”. I had an original thought. I had fun.

    It seems that others prefer to pick the eyes out of z’s words, in order to dismiss them and shield themself from a different way of thinking. I personally see that as exerting yourself in order to stand still. Seems a bit pointless really. Probably get you a good middle management job in Australian manufacturing, though…

    Our society only celebrates critical analysis of what is wrong. Creativity often comes from recognizing and toying with what is good. The former is confining and narrows down the solution space. The latter is generative and expands it.

    Z is the only guy here who takes the time to draw diagrams. Bloody good ones. Do any of his detractors bother to expend as much effort?
    Should we dismiss his ideas just because he is not “one of us”? Does dismissing the different make us more creative thinkers?

    Z is not here to teach detail. When he screams BROWN GO KART, he couldn’t give a ship about BROWN. Or GO. Or KART. The message is THINK OUTSIDE THE SQUARE. LOOK FOR INSPIRATION ANYWHERE. BE ORIGINAL. DON’T FOLLOW THE CROWD. The response? Duh….why brown????

    Z is the guy here to stand up and make a call on the emporer’s new clothes. If you want to reject all he says without looking into his intent, then you are the one at the risk of smugly shouting in your underpants.
    Geoff Pearson

    RMIT FSAE 02-04
    Monash FSAE 05
    RMIT FSAE 06-07

    Design it. Build it. Break it.

  3. #83
    Geoff, you still keep amazing me with your posts! 10000% agreed with you!

  4. #84
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    thanks Harry! Hope you are doing well, mate
    Geoff Pearson

    RMIT FSAE 02-04
    Monash FSAE 05
    RMIT FSAE 06-07

    Design it. Build it. Break it.

  5. #85
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    p.s. how to win FSAE
    1. learn rules
    2. build car to suit

    how to win ten times:
    Repeat above ten times
    Geoff Pearson

    RMIT FSAE 02-04
    Monash FSAE 05
    RMIT FSAE 06-07

    Design it. Build it. Break it.

  6. #86
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    Geoff, sorry that I spewed times not points, but since the discussion was about massively improving acceleration times and EVs vs ICVs we can see the results from the UK.

    Fastest Electric car: 75 points (3.439s)
    Fastest IC car: 38.39 points (4.147s)

    I would say in anyone's language or point sim that 36.61 points is quite a lot!! It is more than the difference between the highest performing IC car and EV car in the comp (around 19 points). In fact that points difference covers the top 5 cars in the field. It was the only event in which the EV cars showed a big points advantage (efficiency also gave a 20 point advantage). In this case the IC car is slower what we normally see as the fastest (closer to 3.9s to 4.0s). That would have still been a deficit of around 25 points.

    If Z is right and an IC car can equal these times it is a worthy exercise to investigate the claims. From a rules perspective if you want to run EVs against ICs and Z is wrong then the rules absolutely need to change. Handing a 35-55 points advantage (efficiency & accel) to the EV cars with no apparent detrimental event (except cost event appears to be a 10-15 point loss) is not something you can overcome by fiddling the concept. Remembering that an IC brown go-kart can be met with an EV brown go-kart. There is no weight penalty for the top EV cars in powertrain anymore.

    Does that satisfy your points requirement Geoff?

    Sorry that I used results rather than a simulation, but the calcs performed earlier back up these sorts of times, and hence points.

    Kev

  7. #87
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    Kev, I'd respond promptly but as you know the internet here in Cockatoo is delivered by horse, and deliveries stop whenever it starts raini.. damn
    Geoff Pearson

    RMIT FSAE 02-04
    Monash FSAE 05
    RMIT FSAE 06-07

    Design it. Build it. Break it.

  8. #88
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    Hi Kev,
    The point I was making was that a fair analysis would cover the whole breadth of the competition. I.e. the two options should be analyzed across all events, cost, energy used, etc. For each of these factors, relative points allocations should be compared.

    I'm sure there is not much new to you there kev.


    Cheers

    Geoff
    Geoff Pearson

    RMIT FSAE 02-04
    Monash FSAE 05
    RMIT FSAE 06-07

    Design it. Build it. Break it.

  9. #89
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    I will try to avoid a two person conversation happening ... especially one between to self-acknowledged gasbags.

    What I am not sure is blatantly obvious is how well a small handful of EV teams have exploited rules that favour EV performance over IC cars. They should be commended for it, and not have their toys taken away. Z is spot on in saying that there is a lot more to look at in the IC cars, but I think way off base in any assumption that would claim parity between EV and IC in the current ruleset.

    Once there is a powertrain performance advantage (power, efficiency, handling) with no noticeable detriment (with cost as the exception) then the solution is clear. It is definitely not an option for all because there is a very large monetary cost associated with the high level EV powertrains.

    I am a big supporter of all teams running points analysis over the full comp. However with some issues there is a clear technical winner. High grip vs low grip tyres for instance, no need to run the points sim on that one. It just so happens that for competitions between EV and IC cars there is a clear winner in the powertrain department. A well executed IC team will not be able to beat a well executed EV team. The points just aren't there. I would also add that people need to chuck the crazy into their points sims even if they don't think it will happen. No one expected the high powered EVs to weigh what they do now, and have enough energy to do the endurance at full tilt. Has everyone considered what an IC car could do if it was 120kg with aero? What would happen if a team had custom made slicks capable of sustained mechanical grip of 2.5g?

    My take is that if your concept is within 10 (maybe 20 points) then you can call it about equal and in with a chance. Anymore and you carry a deficit that is unlikely to be overcome in a large competition (i.e. ~100 teams) The reason for doing the overall comp points analysis is not to show that all concepts have an equal opportunity, it is to try and find if there is a clear winner (or an alternative strategy that differs from the leaders, but close enough to give you a chance). Or to plot out the best value in terms of points per dollar or points per hour. In that equation the IC cars still come out on top.

    I do worry that without careful consideration of where the competition is heading that we will lose something special. Now having been involved with a team building a custom engine I have seen first hand how difficult it is to build a better engine than what you can buy off the shelf. Any team can access (for $2-5k) an engine good enough to build a comp winning IC car around. Build a simple vehicle around that out of fibreglass, glue and balsa, a couple of steel suspension members and you can have an innovative high performance vehicle. With the right skills a team can legitimately build a top level IC car for $20k. ECU's most recent car with carbon folded tub, carbon wings, plenty of spare wheels and tyres, and a custom engine cost around $40-50k. Monash's probably a lot less for more performance. The higher spends on these cars don't translate well to improved performance. Mainly because the nearly all components can be built by students at a very high quality, and there aren't too many of them.

    For the EV programs these amounts of money do not even start to pay the bills.

    Just don't run them against each other. The points sims validate this ... but don't trust me ... do the calcs, and please post the results if they say something different.

    I'm sure there is not much new to you there Geoff.

    Kev

  10. #90
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    I REST MY CASE.
    =============


    Firstly, thanks Geoff for the supportive words.

    I gave the "points argument" for faster Acceleration at the top of page 6 (and some more words later regarding E-Car-bias in Fuel Efficiency). The ~50 points that are on offer from doing Acceleration properly, and the self-evident fact that better straight-line acceleration out of slow speed corners (ie. NO fish-tailing!) also means more points in AutoX and Enduro, are my main reasons for pushing this point.

    (And to repeat "my point", it is that Teams (other than Maryland+) should, for the first time in 30 years, start thinking about weight-distribution and tyre sizes, given FSAE's particular power levels and track layouts. The answer is only "50:50 with equal-sized tyres" when you have a sub-~30kW engine.)

    But I have all but given up trying to help anyone from the "University" system.

    LONG MAY THE DENTALLY-VENTILATED LIVE, for they are the only hope humanity has left...
    ~~~o0o~~~

    PROOF POSITIVE OF MY PREVIOUS POST - The fastest Acceleration time at the just run FSG was ET = 3.36 seconds with Vmax = 115 kph = ~32 m/s (this taken off the web, so I shouldn't trust it, but anyway...).

    This was a 4WD E-Car, but note that,
    * It has LESS POWER than the maximum available to a C-Car (and as noted many times, MAX POWER IS NOT VERY IMPORTANT!!!)
    * It uses the SAME TYRES as those available to ALL other FSAE cars (NOT magical "super-sticky" drag racing hoops). So same Mu, and same Fx/Fz.
    * It set the time on the SAME TRACK as that used by all the other FSAE cars (NOT a specially prepared dragstrip).
    * Its ET and Vmax are remarkably similar to that of Team Toothless's in my last post, so its V-T graph should be very similar to curve B.

    So, to anyone who has a skerrick of understanding of the simplest 1-D Mechanics (ie. as spelt-out in my last post), A SIMILAR TIME IS POSSIBLE FROM A RWD C-CAR! (In fact, see below to see why RWD can be faster.)
    ~~~o0o~~~

    But, in the SAME competition, on the SAME track, with the SAME weather conditions, ALL the C-Cars had the SAME SLOW TIMES that they have been getting for the last 30 years!

    Here, from some earlier posts, are paraphrased the LAME EXCUSES for this PERENNIAL UNDERACHIEVEMENT.

    * "A 200 kg total mass is IMPOSSIBLE because the driver MUST weigh at least 70 kg." - Just really, really stupid!

    * "A lightweight car with a reasonably powerful engine is IMPOSSIBLE... because NO ONE HAS DONE IT YET." - So, you best go back to living in caves.

    * "It is IMPOSSIBLE to go faster, because if the times keep dropping we'll suddenly be at 0.0 seconds..., which is IMPOSSIBLE" - Groaaannnn... How about just taking a few percent off the times each year (which you can do FOREVER!!!)?

    * "It is IMPOSSIBLE to go faster..., err ... unless we spin the tyres impossibly fast..." - Jonny, a lot of the 4.5+ second teams where doing just that.

    * "It is IMPOSSIBLE to go around a corner with a Junior-Dragster tyre. Just IMPOSSIBLE! And even if you could, they'd wear-out INSTANTLY!" - So, you may as well QUIT RIGHT NOW. Go home to Mummy... Or spend 2 x $150 (RRP on link) and have some fun.

    (For the record, I DO NOT think any sort of special tyres are needed for a RWD C-Car to get into the low 3s. But, sadly, I do know of a team of PERENNIAL LOSERS who are planning to spend ~$8,000 on totally inappropriate tyres this year, simply because their $chool gives them a huge wad of cash each year. I say "sadly", because it is my tax dollars they are pissing away!)
    ~~~o0o~~~

    The above are just some examples of the FSAE world's STUPIDITY and LAZINESS. To some degree you can pass the blame for that onto the Education System, for it is they who have fostered your belief that "Going faster is IMPOSSIBLE, just IMPOSSIBLE... But if we keep optimising our ridiculously ornate rockers, then WE DAMN WELL DESERVE OUR GOLD STARS!".

    But you CANNOT BLAME OTHERS FOR YOUR COMPLETE LACK OF WILL TO WIN. All of the knowledge of how to do well in FSAE, both generally and in Acceleration specifically, has been spelled out on this Forum for years. Yet, year after year after year, you all seem oh-so happy to just STAND STILL, DO NOTHING, and GO NOWHERE.

    I pity your children...

    Z

    (PS. I don't know why I bother, but one more time.
    * To get really fast Acceleration times, THE CAR'S CG MUST LIFT as it comes "out of the hole"!
    * This puts MORE THAN 100% of the car's weight on the driving wheels (so faster than 4WD with constant CG height).
    * This "launch" lasts a split-second, and covers ~2 metres.
    * Measure that 2 m time, and get it right.)
    Last edited by Z; 08-03-2014 at 10:08 PM.

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