05-25-2018, 03:09 PM
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#1 (permalink)
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Master EcoModder
Join Date: Sep 2011
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Frogger - '00 Honda Insight Gas Only (unHybrid) 90 day: 68.51 mpg (US)
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Pre-Heating the cat?!
I saw this article today...
https://arstechnica.com/cars/2018/05...id-sports-car/
And it says...
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While I'm in awe of all of the teams' accomplishments, EcoCAR 3 is a competition, and that means there has to be a winner. As mentioned up top, yet again that was The Ohio State, which scored 895 points out of a maximum of 1,000. Among its achievements was a hybrid with 20-percent greater fuel efficiency than the rest, in part thanks to an electrically heated catalyst that dropped emissions upon startup by 85 percent.
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Not sure what that would do for the rest of us who are looking at our bottom line MPG, but curious if anybody has looked into anything like this.
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 Today
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Other popular topics in this forum...
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05-25-2018, 03:33 PM
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#2 (permalink)
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Master EcoWalker
Join Date: Dec 2012
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It isn't a new idea. In fact, it has been produced commercially more than 20 years ago:
Continental Emitec GmbH
Even so, there's a bunch of recent patents:
https://scholar.google.nl/scholar?q=...=1&oi=scholart
One relatively readable scientific publication:
https://pure.tue.nl/ws/files/3268429/Metis237278.pdf
Then there is...
Couldn't resist 
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2011 Honda Insight + HID, LEDs, tiny PV panel, extra brake pad return springs, neutral wheel alignment, 44/42 PSI (air), PHEV light (inop), tightened wheel nut.
  lifetime FE over 0.2 Gmeter or 0.13 Mmile.
For confirmation go to people just like you.
For education go to people unlike yourself.
Last edited by RedDevil; 05-25-2018 at 03:38 PM..
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05-25-2018, 03:47 PM
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#3 (permalink)
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Cyborg ECU
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Quote:
Originally Posted by RedDevil
It isn't a new idea. In fact, it has been produced commercially more than 20 years ago ...
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Totally agreed. I think BMW put electrically preheated CAT in a production vehicle 10 or 15 years ago. I did some light internet research on this about a year or two ago.
I don't see the major fuel economy gains, though, unless it is just by getting into closed loop sooner.
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See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.
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05-25-2018, 03:51 PM
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#4 (permalink)
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Cyborg ECU
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And this looks like a pretty cool set of developments (also a nice abstract of parts of the history):
http://www.emitec.com/fileadmin/user...d_catalyst.pdf
__________________
See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.
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05-25-2018, 03:56 PM
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#5 (permalink)
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Master EcoModder
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Just don't put it in the microwave, mmkay?
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05-25-2018, 08:40 PM
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#6 (permalink)
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EcoModding Lurker
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Quote:
Originally Posted by California98Civic
I don't see the major fuel economy gains, though, unless it is just by getting into closed loop sooner.
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It's not just about getting into closed loop faster. Modern cars are tuned to intentionally waste a bunch of extra fuel in order to heat the cat up faster.
Here are the things the stock tune on my Subaru does to (presumably) heat the cat faster:
- Idles in stratified fueling mode up to coolant temps of 60C (increasing fuel use by at least 50% at idle)
- Retards ignition timing for the first 3 minutes after engine start.
- Retards exhaust cam timing by 20 to 50 degrees until the coolant temperature is above 50C.
- 1800rpm idle speed up to coolant temps of 40C, and even for a while after hot starts.
I've pretty much tuned all these things out, with great benefits to short-trip fuel economy. They don't affect driveability. I can only assume the engine is tuned like this to heat up the cat quickly for regulatory reasons. I'd be surprised if overall NOx emissions were even reduced much.
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Last edited by twj347; 05-25-2018 at 09:15 PM..
Reason: I do what I want
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05-25-2018, 10:13 PM
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#7 (permalink)
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Cyborg ECU
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Quote:
Originally Posted by twj347
...Here are the things the stock tune on my Subaru does to (presumably) heat the cat faster: ... I've pretty much tuned all these things out ...
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How did you find out the tune did all this and how did you adjust the tune? You have one of those software packages for monitoring and editing ECU parameters and such? Pretty cool.
__________________
See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.
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05-26-2018, 03:42 AM
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#8 (permalink)
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It's all about Diesel
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Presumably it's meant with emissions compliance as a higher priority than overall efficiency. But anyway, depending on what kind of heater core it may use, it would eventually be more efficient than other approaches to increase the EGT right after the engine start.
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06-05-2018, 08:24 PM
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#9 (permalink)
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Master EcoModder
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Would thermally insulating the exhaust manifold pipes and cat be at all beneficial?
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06-06-2018, 12:58 PM
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#10 (permalink)
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Engine-Off-Coast
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Quote:
Originally Posted by teoman
Would thermally insulating the exhaust manifold pipes and cat be at all beneficial?
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Yes, I think so. Usually cats have a heat shield on them. I lived in Canada for a few years and I got a car where the heat shield had rusted and fell off my catalytic converter. I fashioned a new one out of sheet aluminum to put back over it.
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