If racing is trying to be green minimum weight rules are wrong
#51
Posted 29 July 2012 - 13:30
* and my car is by no means a sports car... although it does have the engine and driven wheels at proper end of the car
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#52
Posted 29 July 2012 - 20:15
This is a good one. The worst thing you do to your car's fuel economy is start it up on a cold morning and drive reasonably slowly out of your drive and into your local street, where you probably don't tear off at full throttle. Meanwhile you've got your heater on full heat, attempting to bring the interior temp up to nice and toasty. All that heat comes from the cooling system where it should be warming the engine up.
If you have electric seats then (a) you can and will settle for a cooler cabin (b) the electrical load helps to heat the engine up faster. (a) is far more important.
There' also a benefit for cooled seats in hot climates, but they are more difficult to make
Following on from Greg's electric seats improving fuel economy, at the end of any significant journey the engine is up to temperature but then loses all this heat to the atmosphere - why not convert this heat to electricity and store it in a battery. This energy could be used to rapidly heat the engine at the next cold start so improving fuel economy - is this possible / does anybody do this already?
#53
Posted 29 July 2012 - 23:33
How practically?
#54
Posted 29 July 2012 - 23:52
Following on from Greg's electric seats improving fuel economy, at the end of any significant journey the engine is up to temperature but then loses all this heat to the atmosphere - why not convert this heat to electricity and store it in a battery. This energy could be used to rapidly heat the engine at the next cold start so improving fuel economy - is this possible / does anybody do this already?
Already in production, some VW and all current Prius syphon off their engine coolant into a thermos flask. I don't know much about this system, but here's the gen
http://www.google.co...CcWLhrsHtZ4mhXA
#55
Posted 30 July 2012 - 00:27
"why not convert this heat to electricity and store it in a battery."
How practically?
Small Stirling engine driving a generator?
#56
Posted 30 July 2012 - 00:30
Already in production, some VW and all current Prius syphon off their engine coolant into a thermos flask. I don't know much about this system, but here's the gen......
I believe those thermal storage devices are geared more towards reducing emissions than improving efficiency. Modern SI auto engines have incredibly low emissions under most operating conditions. But the one operating condition that is hard to deal with is a cold start. Combustion is not real stable, fuel/air mixing is not so good, and the exhaust catalysts are cold. Lots of unburned HC.
It's similar to the reason cars have vapor recovery and sealed fuel systems. Exhaust catalysts are so effective that the HC emissions from refueling your car can exceed those produced while the engine is running.
#57
Posted 02 August 2012 - 02:31