Go Back   EcoModder Forum > Introductions
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 04-28-2008, 10:29 PM   #1 (permalink)
Master EcoModder
 
Join Date: Apr 2008
Location: Earth
Posts: 303

Pushrod - '02 Chevrolet Cavalier
Thanks: 0
Thanked 8 Times in 4 Posts
Long time modder, 1st time poster :)

Hello everyone. I'm a 23 year old computer programmer and I enjoy squeezing MPGs out of my Cavalier. I also own a Porsche, but that car is strictly for fun and wasting money on.

I'm quite good with electronics and have been programming AVR microcontrollers since 07. I made a simple controller board for my Cavalier's IAC motor to try and lower the idle, but I was unsuccessful. The board worked just fine, but the ECU switching from lean to rich made the reduced idle wander. The next microcontroller project I want to tackle is a board that will take over the fuel injection tasks of the ECU. Once I can take full control of fuel delivery, I'll be able to get a few more city MPGs out of the car.

Recently, I've installed a Bosch wideband O2 sensor in the vehicle, mated to a breadboarded circuit that allows me to maintain a 17.5:1 AFR. From a 50 mile round trip, I averaged 42.8 MPG on E10 87 octane gasoline. I could probably do better on pure gasoline, but I can't find any around these parts. I'll build the circuit into the car this week.

I do have a Scangauge II, but I find it to be unreliable since it cannot read injector pulse widths. It's only accurate for a single AFR, and my car can be anywhere from 12.5:1 all the way up to fuel-cutoff. During FCO, the SG reads 0.8GPH, when the engine is burning no fuel. This makes it impossible for the scangauge to reinforce good driving behavior.

A project I want to start is a true MPG meter, one that connects to the #1 injector and to the VSS lines of the car. That way I will have a very accurate MPG rating regardless of air/fuel ratio or fuel cutoff.

I hope to pick up some good MPG tips from you guys

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 04-28-2008, 10:43 PM   #2 (permalink)
Dartmouth 2010
 
SVOboy's Avatar
 
Join Date: Nov 2007
Location: Hanover, NH
Posts: 6,447

Vegan Powa! - '91 Honda CRX DX
Team Honda
90 day: 66.52 mpg (US)
Thanks: 92
Thanked 122 Times in 90 Posts
Send a message via AIM to SVOboy Send a message via MSN to SVOboy Send a message via Yahoo to SVOboy
Welcome to the site, I would check out the instrumentation/mpguino subforum, you'll find some stuff right up your alley there.

Great to have you aboard!
  Reply With Quote
Old 04-28-2008, 11:20 PM   #3 (permalink)
Future EV Owner
 
Join Date: Mar 2008
Location: Sussex Wisconsin
Posts: 674

Wannabe - '05 Honda Civic LX
90 day: 40.53 mpg (US)
Thanks: 0
Thanked 4 Times in 4 Posts
Welcome JG!

The Cavalier is a great car to mod. My son is looking forward to working on his once school is out. You should add your car to the EM Garage.
__________________
  Reply With Quote
Old 04-29-2008, 02:26 AM   #4 (permalink)
Future EV Owner
 
Join Date: Mar 2008
Location: Sussex Wisconsin
Posts: 674

Wannabe - '05 Honda Civic LX
90 day: 40.53 mpg (US)
Thanks: 0
Thanked 4 Times in 4 Posts
Hey, JG, here's a fuel log of one of our member's Cavalier. It should give you some inspiration.

http://ecomodder.com/forum/em-fuel-l...?vehicleid=155


http://ecomodder.com/forum/emgarage....&vehicleid=155
__________________
  Reply With Quote
Old 04-29-2008, 08:59 AM   #5 (permalink)
Master EcoModder
 
Join Date: Apr 2008
Location: Earth
Posts: 303

Pushrod - '02 Chevrolet Cavalier
Thanks: 0
Thanked 8 Times in 4 Posts
Wow, phleas is putting down some great numbers!

Our vehicles are just a little different. Mine was the last year of the 2200 motor, which is a 2.2L 8 valve pushrod. He has the 2.2L 16v DOHC Ecotec. Both are rated 33mpg highway by 2007 ratings.

Unfortunately, I'm not going to be able to put down all highway tanks like he does. My work commute is 3.2mi of city driving on a cold engine.

I'd be interested to know which mods got him that huge increase. I'm considering fiberglassing a belly pan as well.
  Reply With Quote
Old 04-29-2008, 09:30 AM   #6 (permalink)
Administrator
 
Daox's Avatar
 
Join Date: Dec 2007
Location: Germantown, WI
Posts: 11,203

CM400E - '81 Honda CM400E
90 day: 51.49 mpg (US)

Daox's Grey Prius - '04 Toyota Prius
Team Toyota
90 day: 49.53 mpg (US)

Daox's Insight - '00 Honda Insight
90 day: 64.33 mpg (US)

Swarthy - '14 Mitsubishi Mirage DE
Mitsubishi
90 day: 56.69 mpg (US)

Daox's Volt - '13 Chevrolet Volt
Thanks: 2,501
Thanked 2,585 Times in 1,553 Posts
Welcome to the site.

His biggest mod would be to his right foot (aka driving technique). It'll net you more mpg and cost less than any modification. The best article is actually here on driving technique.

I hate to sound like a broken record (I've mentioned this to others recently), but you do know by leaning out your fuel mixture you are going to increase NOx emissions which cause some pretty ugly damage to the environment, right?
__________________
Current project: A better alternator delete
  Reply With Quote
Old 04-29-2008, 09:47 AM   #7 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,513

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

MPGiata - '90 Mazda Miata
90 day: 52.71 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car - '14 Mitsubishi Mirage ES (base)
90 day: 60.16 mpg (US)
Thanks: 4,058
Thanked 6,957 Times in 3,602 Posts
Quote:
Originally Posted by JohnnyGrey View Post
My work commute is 3.2mi of city driving on a cold engine.
Not if you use a block heater.

Also, with that commute length, sounds like you're a good candidate for the "bicycle" mod , at least in good weather.

Anyway, welcome to the forum! As Ben noted, maybe you'll be able to sink your chops into the open source fuel economy computer project.
__________________
Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
Mitsu mods: 70 MPG in my ecomodded, dirt cheap, 3-cylinder Mirage.
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 04-29-2008, 09:47 AM   #8 (permalink)
Master EcoModder
 
Join Date: Apr 2008
Location: Earth
Posts: 303

Pushrod - '02 Chevrolet Cavalier
Thanks: 0
Thanked 8 Times in 4 Posts
Quote:
I hate to sound like a broken record (I've mentioned this to others recently), but you do know by leaning out your fuel mixture you are going to increase NOx emissions which cause some pretty ugly damage to the environment, right?
Absolutely. However, if you look at what happens in a typical engine, you'll find the increase isn't as dramatic as what some people make it out to be. More on the order of 20%, so I figure my 2.2L's NOX emissions are similar to that of a stock 2.7L. Our environmental standards limit PPM, not total NOX output. If that were the case, you wouldn't see any SUVs on the road. I like to look at the glass half full, so think of it as a 2.7L motor with the fuel consumption of a 1.8L



Actually, if you compare the NOX output between the stock 14.7:1 ratio and the 17.4:1 ratio I'm running at, my NOX emissions might be a little less than stock, not to mention HC emissions!
Attached Thumbnails
Click image for larger version

Name:	fic-af-emissions.gif
Views:	752
Size:	13.7 KB
ID:	646  
  Reply With Quote
Old 04-29-2008, 06:38 PM   #9 (permalink)
Future EV Owner
 
Join Date: Mar 2008
Location: Sussex Wisconsin
Posts: 674

Wannabe - '05 Honda Civic LX
90 day: 40.53 mpg (US)
Thanks: 0
Thanked 4 Times in 4 Posts
Quote:
Originally Posted by JohnnyGrey View Post
Wow, phleas is putting down some great numbers!

Our vehicles are just a little different. Mine was the last year of the 2200 motor, which is a 2.2L 8 valve pushrod. He has the 2.2L 16v DOHC Ecotec. Both are rated 33mpg highway by 2007 ratings.

Unfortunately, I'm not going to be able to put down all highway tanks like he does. My work commute is 3.2mi of city driving on a cold engine.

I'd be interested to know which mods got him that huge increase. I'm considering fiberglassing a belly pan as well.
Don't dispair. I usually go 50% highway, but today I took a more rural route with a few stops. Although I had to stop 4 or 5 extra times, I was able to go a little slower and take advantage of more coasting opportunities that would have been useless at a higher speed. The difference was a 5 mpg increase! I will continue to test this route for the next few days. Never give up!

__________________
  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Long time GS/Ecomodder lurker LostCause Introductions 6 02-24-2008 08:52 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com