Greetings From the Shakedown
This Edison2 team was driven right against the breaking point when getting the cars ready. It was the most impressive effort I have ever been part of. There were stressed moments but we never dropped the ball. The cars were in Michigan at the prescribed time by a margin of 90 minutes, following a relentless effort in the Lynchburg shop.
We are in the second day of the X Prize Shakedown stage; half of 28 teams remaining in the competition are with us at the Michigan International Speedway this week, the other half come next week. Yesterday and today was spent with our 4 cars undergoing technical inspections (yes, 4 cars; other teams have one or two; we are entered in all 3 classes, with 2 vehicles in the mainstream class).
Our cars made it through tech on all the important safety issues. More evaluations for the rest of the week, with time on the track. Getting 100 mpg is difficult and will become clear as in my opinion only a few teams have a realistic chance of success. The lesson of pure efficiency - the message of low mass and good aerodynamics - will sound loud and clear.
There are an impressive array of specific solutions here: some very nice electric car installations and some very heroic combinations of different approaches. However, the hurdles are set high and only the very careful and very well executed solution will stand the test of this X Prize.
There is a reason why the big automobile manufacturers have not done it. It is really hard to do…
Oliver
Reader Comments (6)
Can you tell us anything about the difference between the two Mainstream class cars?
Good luck gang!
I have switched from following Aptera to following Edison2. Your integrity and relentless dedication to low mass/drag are the reason. The blog is outstanding, and I'm looking forward to any updates you can squeeze out during this challenging time -- even a tiny one.
I have complete faith in your principles and admire your courage to uphold them. Your platform will indeed speak loud and clear in this contest. Go get 'em!!!
At the Shakedown the difference was one car had an EFI and one a Motec Control unit and the EFI had a larger plenum. We compared detail solutions.
Conclusion: We will run the Motec ECUs only. We will run EFI data logger and Morray (mandated by X Prize) and we will run EFI Dash logic. For the plenums we must do another test. The weight difference in the cars was 3 lbs. (probably because we rushed on the body. Otherwise they are inter-changeable. The Motec car is VLC 007 and the EFI was 005.
These cars are very busy as we do not have enough hardware:
tomorrow 007 meets with me and Barnaby for aero work on the radiator.
007 is going to make a very important presentation on Monday . - wish us good luck. I will let you know as soon as I can what it was if it works...
Tuesday morning to Roush emissions for cold start work for a few weeks ...
There is a reason big companies are big. this is really hard but it is all happening.
I have a great crew and quite a few insider believers who get it.
Hello Oliver,
Thanks for keeping me keyed in on your progress.
I think perhaps you are not quite correct in your evaluation of regenertive braking. And no, it is not perfect, but the losses are not in inertia of the drive train, they are in the imperfect ability to capture that inertial energy and get it into batteries. The electrical losses are where you take the hit. Whatever kinetic energy you get from braking that goes into the drive train is theoretically possible to convert to electrical energy. There is a lot of room for imperfection since all such devices lose some energy. However, if done right it can be quite effective.
The implication of what I say here is that the very light feature has less importance if the regenerative braking is done right. Theoretically, if you ignore conversion losses that is, the weight is not so important in the efficiency equation. It shows up significantly as a factor that increases rolling resistance in the tires, and that is probably the most important impact of weight, and is not so easily defeated. In a real world weight does count, but perhaps not as much as you now seem to be thinking.
Still, your capability to implement your ideas is very impressive. Good luck.
Oliver - I saw on the Edison2 Facebook pages that you had some issues with pre-detonation. Just a random thought (if you guys already haven't tried it) - have you tried intercooling the EGR gas as well as the turbo output? Seems like it wouldn't be too hard to do....and might help this issue by reducing the inlet temp. Might also allow you to run a bit higher compression ratio too. Also, if you've got extra power to spare - you might try having the inlet valve close early (or late) - to convert the engine to an "atkinson cycle" where the expansion ratio is greater than the compression ratio. This will give you higher efficiency (try googling Atkinson Cycle). Good Luck, Kevin
Oh...and don't forget (sorry if I'm annoying you with things you guys already know or have tried) - if you change the valve timing to Atkinson, you'll need to pop-in a higher compression piston, just to get back to the original effective C.R. because the chamber isn't starting with a full charge. Kevin