Batman we have lean burn! 49.6 mpg! - Page 8 - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Reply
 
Thread Tools Display Modes
 
Old 08-05-2007, 11:59 AM   #71
Supporting Member
 
cfg83's Avatar
 
Join Date: Sep 2006
Posts: 1,779
Country: United States
popimp -

Quote:
Originally Posted by popimp View Post
cfq83:

Did it work for you?
From the limited data I was seeing, I don't think it was working for me. I predicted seeing the A/F ratio getting more lean with the mod, but it was still in the 14.7 range. I also wanted to capture the other data (MPG/IGN/TPS/MAP) to see if the ECU/PCM was modifying other settings in reaction to the IAT mod. Here is why my experminent failed :

Attachment 812

The A/F meter is legible, but the scangauge is not. If I had prepped the setup to get the lighting under control, then I think it would have worked. My plan was to enter each change in value in a spreadsheet and average the totals.

Note : Filming the scangauge is a kind of "poor man's carchip" :
http://www.davisnet.com/drive/produc...p_products.asp

Note : When the engine is cold and in open loop, I do think the IAT mod works, because I was definitely observing a bias in the A/F.

CarloSW2
Attached Thumbnails
Click image for larger version

Name:	scangauge.bad.2.jpg
Views:	267
Size:	25.5 KB
ID:	695  
__________________

__________________
Old School SW2 EPA ... New School Civic EPA :

What's your EPA MPG? http://www.fueleconomy.gov/feg/calculatorSelectYear.jsp
cfg83 is offline   Reply With Quote
Old 08-05-2007, 02:54 PM   #72
Stay true to the Game!
 
popimp's Avatar
 
Join Date: May 2007
Posts: 303
Country: United States
So can we put the resistor mod in the busted field for Dodge Grand Caravan and Saturn?
__________________

__________________


popimp is offline   Reply With Quote
Old 08-05-2007, 10:17 PM   #73
Supporting Member
 
cfg83's Avatar
 
Join Date: Sep 2006
Posts: 1,779
Country: United States
popimp -

Quote:
Originally Posted by popimp View Post
So can we put the resistor mod in the busted field for Dodge Grand Caravan and Saturn?
Most probably, but I don't want to say for sure because my test failed .

CarloSW2
__________________
Old School SW2 EPA ... New School Civic EPA :

What's your EPA MPG? http://www.fueleconomy.gov/feg/calculatorSelectYear.jsp
cfg83 is offline   Reply With Quote
Old 08-06-2007, 10:19 AM   #74
Registered Member
 
unstable bob's Avatar
 
Join Date: Jul 2007
Posts: 158
Country: United States
Send a message via AIM to unstable bob
Angry

Quote:
Originally Posted by popimp View Post
So can we put the resistor mod in the busted field for Dodge Grand Caravan and Saturn?
I'm trying an IAT mod right now in my Cavalier, using a potentiometer to set the incoming air @ 222 degrees. Doesn't look too promising so far, and I may in fact be losing MPG. I should have some more concrete evidence later in the week.
__________________
unstable bob gable
AMERICAN ROAD WARRIOR!

www.unstablebobgable.com

1973 AMC AMX: The beauty
1987 Buick T-Type: The beast
2004 Cavalier: The MPG machine
unstable bob is offline   Reply With Quote
Old 08-06-2007, 12:46 PM   #75
Registered Member
 
Join Date: Jul 2007
Posts: 280
Country: United States
Quote:
Originally Posted by cfg83 View Post

Note : When the engine is cold and in open loop, I do think the IAT mod works, because I was definitely observing a bias in the A/F.

CarloSW2

That's what I was expecting, when in open loop the ecu has to use the inputs it has to determine fuel and IAT is am important part, so it will see it's hot out and use less fuel.

Once closed though it will adjust almost solely based on the O2 sensor, some ECUs have only a 'range' of adjustment to a fuel calculation (that's the same as open loop), so the calculation will say to run at 16:1 and then in closed loop it'll know it's lean and adjust as much as it can but can only add a certain amount of pulsewidth and so will end up lean still (like 15:1).

I could see other ECUs adjusting totally on the O2 or allowing more pulsewidth adjustment and holding you at 14.7.

That's why I always thought the resistor inline with the O2 sensor was a better mod, since it change the target AFR itself (of course you'd better get a digital AFR gauge or something so you can really tune how much resistance yields whichever results). This also shouldn't affect the AFR at WOT since it will just ignore the O2 sensor and calculate fuel just like it always has.

Of course best would be to have a stand alone (programmable) ECU with a wideband O2 sensor so you can just dial in the AFR you'd like.

For your digital gauge did you install a wideband sensor or is it just reading your stock sensor?




Also, asked way above about how to know if you're too lean, install an EGT gauge (Exhaust Gas Temp) that will show you if you're getting to dangerous levels (like the melting point of iron).
itjstagame is offline   Reply With Quote
Old 08-06-2007, 01:52 PM   #76
Supporting Member
 
cfg83's Avatar
 
Join Date: Sep 2006
Posts: 1,779
Country: United States
itjstagame -

Quote:
Originally Posted by itjstagame View Post
That's what I was expecting, when in open loop the ecu has to use the inputs it has to determine fuel and IAT is am important part, so it will see it's hot out and use less fuel.

Once closed though it will adjust almost solely based on the O2 sensor, some ECUs have only a 'range' of adjustment to a fuel calculation (that's the same as open loop), so the calculation will say to run at 16:1 and then in closed loop it'll know it's lean and adjust as much as it can but can only add a certain amount of pulsewidth and so will end up lean still (like 15:1).

I could see other ECUs adjusting totally on the O2 or allowing more pulsewidth adjustment and holding you at 14.7.

That's why I always thought the resistor inline with the O2 sensor was a better mod, since it change the target AFR itself (of course you'd better get a digital AFR gauge or something so you can really tune how much resistance yields whichever results). This also shouldn't affect the AFR at WOT since it will just ignore the O2 sensor and calculate fuel just like it always has.

Of course best would be to have a stand alone (programmable) ECU with a wideband O2 sensor so you can just dial in the AFR you'd like.
I wish I knew a year ago what I know now. I would have gone with something along the line of DRW's Apex SAFC fuel controller that he has in his Plymouth Laser.

Quote:
For your digital gauge did you install a wideband sensor or is it just reading your stock sensor?
It's reading the stock narrow-band sensor. After it arrived, I was worried that it was wide-band only, so I e-mailed the manufacturer, and they assured me that it was narrow-band compatible.

I have also read in the net that it can be modified to read wide-band, but I don't have the URL in front of me.

Quote:
Also, asked way above about how to know if you're too lean, install an EGT gauge (Exhaust Gas Temp) that will show you if you're getting to dangerous levels (like the melting point of iron).
I also have a high temperature probe kit for just this purpose :

High Range Adjustable Temperature Switch with LCD
http://www.jaycarelectronics.com/pro....asp?ID=KC5376

But, I haven't built it yet.

CarloSW2
__________________
Old School SW2 EPA ... New School Civic EPA :

What's your EPA MPG? http://www.fueleconomy.gov/feg/calculatorSelectYear.jsp
cfg83 is offline   Reply With Quote
Old 08-06-2007, 03:44 PM   #77
Supporting Member
 
lovemysan's Avatar
 
Join Date: Jun 2006
Posts: 595
Country: United States
Well I'll update my findings. I removed my IAT resistor. I had to recalibrate the SG. I reworked my HAI for more consistant hot air. I also work to keep the temps above 150 and below 190. I'm getting better mileage. I'm 3 days away from my first mixed driving 50mpg+ tank. For me the resistor mod is busted! I'm getting 57mpg around town. I can get 59mpg @50-55mph. Next up is a block heater and sealing the engine compartment.
__________________
02 Saturn SL
5 speed
for pics click the link below

http://s75.photobucket.com/albums/i3...emysan/saturn/

[SIGPIC][/SIGPIC]
"for best mileage swap in a d15z1"
lovemysan is offline   Reply With Quote
Old 08-07-2007, 12:27 PM   #78
Registered Member
 
Join Date: Jul 2007
Posts: 280
Country: United States
cfq83: Those are pretty sweet kits. I bought a kit to learn programming a pic controller myself but just haven't had the time to play with it. I think what I'd really prefer is the exact voltage that being outputted by the sensor, but I guess the LEDs are enough to give an idea of where you're running.
itjstagame is offline   Reply With Quote
Old 08-07-2007, 12:43 PM   #79
Supporting Member
 
cfg83's Avatar
 
Join Date: Sep 2006
Posts: 1,779
Country: United States
itjstagame -

Quote:
Originally Posted by itjstagame View Post
cfq83: Those are pretty sweet kits. I bought a kit to learn programming a pic controller myself but just haven't had the time to play with it. I think what I'd really prefer is the exact voltage that being outputted by the sensor, but I guess the LEDs are enough to give an idea of where you're running.
Yeah, I really like the jaycar stuff. Cool kits that are car focused and at a decent price. They seem to link their car-mod articles with the kits, so there is more explanation than just the assembly instructions.

If you want the exact voltage, then all you need is a multimeter, but it would need a major refresh rate if it is digital.

CarloSW2
__________________
Old School SW2 EPA ... New School Civic EPA :

What's your EPA MPG? http://www.fueleconomy.gov/feg/calculatorSelectYear.jsp
cfg83 is offline   Reply With Quote
Old 08-07-2007, 12:52 PM   #80
Registered Member
 
Join Date: Jul 2007
Posts: 280
Country: United States
Hmm, yeah, I just found these:
http://www.allelectronics.com/cgi-bi...810&type=store
http://www.harborfreight.com/cpi/cta...emnumber=90899

At those prices it's cheaper to just hook or hack one of those up as a permanent install. I'm actually picturing pulling a couple different + lines (like from O2, Water temp, IAT, etc) and a negative line all to under the dash with some kind of convenient connectors and just plug the probes on my dash mounted multimeter on whatever I want to test.

You're right though about the refresh rate, the one say about 2.5sec! I don't really want to see it bouncing all over anyway, I think what I need is two displays, one showing the most recent max and the other showing the most recent min.

What does your do, average over the past however many microsecs?

If only I weren't so cheap :-).
__________________

itjstagame is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Number Section of iOs keyboard boostventilator Fuelly Web Support and Community News 5 09-23-2012 10:23 AM
Not very precise mpg calculation larjerr Fuelly Web Support and Community News 4 08-20-2012 02:03 AM
A Couple of Possible Additions mechjames Fuelly Web Support and Community News 3 02-13-2010 11:16 AM
"active" aero grille slats on 06 civic concept MetroMPG General Fuel Topics 21 01-03-2006 01:02 PM

Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 08:36 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.