Go Back   EcoModder Forum > EcoModding > Aerodynamics
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 12-29-2007, 02:03 PM   #31 (permalink)
Master EcoModder
 
basjoos's Avatar
 
Join Date: Dec 2007
Location: Upstate SC
Posts: 1,051

Aerocivic - '92 Honda Civic CX
Last 3: 70.54 mpg (US)

AerocivicLB - '92 Honda Civic CX
Team Honda
90 day: 55.14 mpg (US)
Thanks: 6
Thanked 563 Times in 269 Posts
Quote:
Originally Posted by martae View Post
Great job Basjoos, but why didn't you start with a civic VX instead of a CX ? It was the high mileage model. Feather light aluminum wheels. Wider ratio transmission with a higher final drive ratio (2000 rpm at 60 mph). Variable valve timing with a twist. In this engine only one intake valve opens below 2500 rpm. Since there is only one intake valve open more of the pressure drop between the atmosphere and the cylinder is across the valve rather than the throttle plate. This gives a more turbulent fuel air mixture which allows a leaner fuel/air charge, greater torque at low engine speed, and no predetonation . The use of a very sensitive oxygen sensor (unique to the VX) allows more precise control of the FA mixture making a very low idle possible. On a warm day mine idles at about 500 rpm. The practical effect of these engine tweaks is high torque at low RPM sort of like a diesel. As I'm sure you guys know, the great weakness of the Otto cycle (the spark igniton gasoline engine is an Otto cycle engine) are the large pumping losses at part load caused by sucking the FA charge past the throttle plate. The ability of this engine to deliver good torque at low RPM (and thus lower pumping losses) is the secret to the high fuel economy this car delivers. The CX and the VX share the same body, but the CX is listed at EPA 42/46 and the VX at 47/56. The VX also offers higher power since the engine has the same displacement, but four valves per cylinder (92 vs 70). I bought mine new in 1992, have put 208 thousand miles on it and still average 45 mpg to work and around town. When the car was new 52 or 53 mpg was not unusual on a long road trip. The fact Honda could do this with the technology of 15 years ago shows what a bunch of liars the auto companies are when they squeal about a 35 mpg average fuel economy rule.

I started with a CX (which I had bought new in 92) rather than a VX because that was the car I was driving at the time I decided to start aero modding my car. The CX and VX share the same transmission. The main differences being the in engine,, lighter wheels, some additional interior features in the VX (the CX is the bare bones Civic model) and some underbody aero to slightly reduce the Cd of the VX. The VX and CX have the same weight. When new, my CX typically gave me 51mpg on the highway in the summer (44mpg highway in the winter) and 38mpg was the worst I ever got with it (in snow driving and winter tires). Interestingly, when I installed a DX engine at 245,000 miles (but kept the same transmission), the mileage remained the same, but my 0 to 60 times dropped to 10 sec.

__________________
aerocivic.com
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 12-29-2007, 05:20 PM   #32 (permalink)
Dennis the Menace
 
Join Date: Dec 2007
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Exhaust / Coolant / Air intake

You were talking about changing the intake for the coolant to vary with need of cooling, have you thought of a heat exchanger for the intake air for combustion or for that matter from you exhaust, routing the cool air through the rad, then to an exhaust heat exchanger then to the engine, in effect reclaiming the heat that would have been waisted... there is an interesting article in Popular Science about using the heat to produce steam in the engine...

http://www.popsci.com/popsci/technol...cbccdrcrd.html
  Reply With Quote
Old 12-29-2007, 08:04 PM   #33 (permalink)
Master EcoModder
 
basjoos's Avatar
 
Join Date: Dec 2007
Location: Upstate SC
Posts: 1,051

Aerocivic - '92 Honda Civic CX
Last 3: 70.54 mpg (US)

AerocivicLB - '92 Honda Civic CX
Team Honda
90 day: 55.14 mpg (US)
Thanks: 6
Thanked 563 Times in 269 Posts
I figure my intake air gets warm enough just from the tightly cowled engine compartment (its completely underpanelled, with a mostly blocked grill and the hot radiator air exhausted out through the front wheel wells). They've had some discussions of warm air intake temps at Gassavers and concluded that although warm intake air improves mileage (at the expense of power, you are in effect driving a less powerful engine with a more open throttle plate with reduced pumping losses), but if the intake air gets too hot, it has detrimental effects on mileage (perhaps because the engine ECU isn't programmed to handle intake temps that are way above what its programmers thought it might ever experience).
__________________
aerocivic.com
  Reply With Quote
Old 12-30-2007, 11:52 AM   #34 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 21,463

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 52.8 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
90 day: 73.57 mpg (US)

Fancy Metro - '14 Mitsubishi Mirage top spec
90 day: 58.72 mpg (US)
Thanks: 3,231
Thanked 6,085 Times in 3,153 Posts
70 years ago... the aero Model T

FYI - for those interested in the subject of radical aero mods, you might want to check the thread about Harry Stevinson, my friend's dad. He was bitten by the same bug that got basjoos ... 70 years ago:

__________________
Latest mods: 3-cylinder Mitsubishi Mirage. EcoMods now in progress...
Ecodriving test:
Manual vs. automatic transmission MPG showdown



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
Old 12-30-2007, 05:40 PM   #35 (permalink)
Master EcoModder
 
basjoos's Avatar
 
Join Date: Dec 2007
Location: Upstate SC
Posts: 1,051

Aerocivic - '92 Honda Civic CX
Last 3: 70.54 mpg (US)

AerocivicLB - '92 Honda Civic CX
Team Honda
90 day: 55.14 mpg (US)
Thanks: 6
Thanked 563 Times in 269 Posts
All of this recent activity used up all of this month's bandwidth on my free Photobucket account. Next month's bandwidth allotment will become available on Jan 2.
__________________
aerocivic.com
  Reply With Quote
Old 12-30-2007, 06:04 PM   #36 (permalink)
Dartmouth 2010
 
SVOboy's Avatar
 
Join Date: Nov 2007
Location: Hanover, NH
Posts: 6,427

Vegan Powa! - '91 Honda CRX DX
Team Honda
90 day: 66.52 mpg (US)
Thanks: 92
Thanked 114 Times in 82 Posts
Send a message via AIM to SVOboy Send a message via MSN to SVOboy Send a message via Yahoo to SVOboy
If you want to send me the pictures I can host them on the ecomodder server for you.
  Reply With Quote
Old 12-31-2007, 11:43 AM   #37 (permalink)
EcoModding Lurker
 
Join Date: Dec 2007
Location: Iowa, USofA
Posts: 17
Thanks: 0
Thanked 0 Times in 0 Posts
The images can also be seen at this site: http://www.cleanmpg.com/photos/showg...=500&ppuser=18
  Reply With Quote
Old 01-01-2008, 12:20 PM   #38 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 21,463

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 52.8 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
90 day: 73.57 mpg (US)

Fancy Metro - '14 Mitsubishi Mirage top spec
90 day: 58.72 mpg (US)
Thanks: 3,231
Thanked 6,085 Times in 3,153 Posts
Quote:
Originally Posted by basjoos View Post
All of this recent activity used up all of this month's bandwidth on my free Photobucket account. Next month's bandwidth allotment will become available on Jan 2.
I've posted the images on the Ecomodder server - they're all visible now. No more Photobucket bandwidth problems.
__________________
Latest mods: 3-cylinder Mitsubishi Mirage. EcoMods now in progress...
Ecodriving test:
Manual vs. automatic transmission MPG showdown



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
Old 01-01-2008, 03:35 PM   #39 (permalink)
EcoModding Lurker
 
Join Date: Dec 2007
Location: Iowa, USofA
Posts: 17
Thanks: 0
Thanked 0 Times in 0 Posts
If we get the aftermarket body mod industry to start thinking ecomodding, changes like the ones Basjoos has made might be accomplished in a weekend. See: http://www.bodykits.com/store/home.php?cat=1281 as an example.
  Reply With Quote
Old 01-01-2008, 03:38 PM   #40 (permalink)
Dartmouth 2010
 
SVOboy's Avatar
 
Join Date: Nov 2007
Location: Hanover, NH
Posts: 6,427

Vegan Powa! - '91 Honda CRX DX
Team Honda
90 day: 66.52 mpg (US)
Thanks: 92
Thanked 114 Times in 82 Posts
Send a message via AIM to SVOboy Send a message via MSN to SVOboy Send a message via Yahoo to SVOboy
I do believe newton has had that thought (of making aero body kits for ecomodders), and I definately think it's worth a go. If I knew anything about molding and all that jazz I might play with it myself...

If someone made a boattail for a prius I'm sure that would get the business going.

  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
aero mods-data-% change or Cd change ( installment # 7-Wheels/Tires/Wheelcovers/etc. aerohead Aerodynamics 5 06-04-2014 12:14 PM
[aero-mods(aft-body streamlining/boat-tails)Part-3 History/Timeline cont'd aerohead Aerodynamics 10 08-13-2010 12:50 AM
mods-data-% change or Cd change( installment#5-roofline data) aerohead Aerodynamics 3 09-26-2009 02:01 PM
Build Thread Key Postings Index Experiment. TestDrive Forum News & Feedback 7 02-15-2009 08:53 PM
Drafting and Cd reduction basjoos Aerodynamics 5 12-06-2008 10:45 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com