This is a humorously-titled reflection after ASC 2018, aimed at figuring out why our car seemingly does worse compared to the competition. Hopefully we can identify areas of improvement, knowing that these are obtainable baselines that other teams are able to meet.
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300 miles - 242 miles = 58 miles |
Where are the other 58 miles going?
In order to be competitive with teams that are racing at WSC, we drastically need to improve our energy consumption.
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WSC = 3020 km
WSC duration = 6 days
3020 km / 6 days = 503.333333 km / day |
If we assume we were able to maintain 390 km every day, we would still be short 113 km of range. Either our aero is really bad, or there are losses being incurred somewhere (say via damaged tyres, friction of tires rubbing against fairings, etc.) that we didn't account for.
Note: We were targeting a cruise speed of 60 km/h (37 mph), but App State averaged a minimum of 42 mph assuming they started at 9 am and travelled 210 miles by 2 pm. We found that going 6 mph faster significantly increased our current draw so it would be unlikely that we would make 242 miles with 40+ mph.
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Our NGM SC-M150 motors struggled a bit climbing the hill on our hill-start.
IV. Motor Controllers
App StateWe were running into a lot of issues with our Motor Controllers overheating. Supposedly a lot of teams either run with the WaveSculptor 20 setup that we have, or the WaveSculptor 22. This resulted in us having to frequently stop and allow them to cool down.
V. Regen & Brakes
I was talking to App State after the stage stop on Day 6, and their driver was saying how he was regen-braking the whole way down the hill.
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| Team | Weight (kg) |
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| App State | 362 |
| Bologna | 300 |
| Minnesota | 380 |
| Waterloo | 475 |
| PrISUm | 1150520 |
Considering PrISUm didn't qualify, this really does make you think 🤔I also highly doubt that PrISUm's car is actually 1150 kg, otherwise it's a wonder they are able to trailer it anywhere.
I don't think we need to go full-on carbon fiber like Bologna (nor do we have the expertise), but we can definitely identify areas where there are potential weight-savings.
We had initially projected 506.9 kg as the upper bound our weight in our weight budget (which included 2 drivers and their ballast). Our weight without the dropout and fairings (probably 10-20 kg in total) was 632.5 kg.
Even if we ignore the dropout and fairings, this a pretty big difference (~20%). It would be good to understand where we can save weightthe additional weight is coming from, and what the actual breakdown is, so we know what to optimize.
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632.5 kg - 506.87 kg = 125.63 kg |
There might be value in revisiting the original weight budget and comparing to see whether we were off in our projections (and if so, where?), or if there were items that were missed.