Go Back   EcoModder Forum > Introductions
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 03-17-2014, 12:01 PM   #11 (permalink)
EcoModding Apprentice
 
KrautBurner's Avatar
 
Join Date: Mar 2014
Location: SUNNY Sequim, Wa
Posts: 238

Cavalier of D00M - '05 Pontiac GTO LS2 T56
90 day: 23.2 mpg (US)

The New One - '10 Toyota Prius II
90 day: 51.55 mpg (US)

Chick Magnet - '91 Geo Metro 3cyl/5sp
90 day: 48.07 mpg (US)
Thanks: 79
Thanked 39 Times in 33 Posts
Quote:
Originally Posted by dtmerritt View Post
OK, here is where I need your help! I know manufacturers set the mixture at 14.7 for the catalytic converter, which I don't have. I know leaner ratios are better for mileage, but without running too lean, what ratio should T strive for?
I'm fairly confident there was no cat on a car built in 1955

but a wideband O2 sensor could be helpful, and or a Pyrometer
you may also want to look into a vacuum gauge

__________________
2005 GTO 6.0 V8 (600hp)

1991 Geo Metro 1.0 3/5 base

2010 Prius II (replaced 2001 Tahoe 5.3 V8 April 2014)

1994 F-350 7.3 TurboDiesel (Rollin' Coal)
  Reply With Quote
The Following User Says Thank You to KrautBurner For This Useful Post:
dtmerritt (03-17-2014)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 03-17-2014, 01:18 PM   #12 (permalink)
Master EcoModder
 
Join Date: May 2012
Location: USA
Posts: 2,643
Thanks: 1,503
Thanked 276 Times in 226 Posts
Just remember running lean and cranking up the timing will raise your NOX levels if you are subject to any emissions testing.
  Reply With Quote
The Following User Says Thank You to Cobb For This Useful Post:
dtmerritt (03-17-2014)
Old 03-17-2014, 01:57 PM   #13 (permalink)
Master Novice
 
elhigh's Avatar
 
Join Date: Jan 2008
Location: SE USA - East Tennessee
Posts: 2,285

Josie - '87 Toyota Pickup
90 day: 28 mpg (US)

Felicia - '09 Toyota Prius Base
90 day: 48.42 mpg (US)
Thanks: 403
Thanked 592 Times in 434 Posts
Those older rides are usually grandfathered out of emissions testing. I can imagine some nanny state looking over your shoulder but I don't realistically expect it, not with a '55.

The O2 sensor won't help his car but it could go a long way to helping with the tuning, hooked up to an AFR gauge on the dash or even just a handheld.

I wonder what it would take to retrofit an on-the-fly mix control like in light planes? They have to be adjustable while running to compensate for air density changes as the plane gains altitude. I know we have some light plane pilots on this forum, anyone want to weigh in on that idea?

My truck has a carb. Leaning it out for highway cruising would be pretty sweet.
__________________




Lead or follow. Either is fine.
  Reply With Quote
The Following User Says Thank You to elhigh For This Useful Post:
dtmerritt (03-17-2014)
Old 03-17-2014, 02:12 PM   #14 (permalink)
Burn lean and prosper\\//
 
Join Date: Jul 2012
Location: scranton pa
Posts: 576

VLX - '93 Honda Civic VLX
Team Honda
90 day: 51.1 mpg (US)
Thanks: 55
Thanked 65 Times in 54 Posts
Personally I would adjust carb, points, ignition timing to stock for the trip. I wouldn't risk doing damage.

However when you get it home then I would have some fun. I'm on the same page I'm building a 68 rambler American and I can't wait to start playing around with the carb for fuel economy.

Couple notes-
Don't waste money on a 30 dollar afr gauge. They only come with the gauge and are made to wire into the signal wire of a narrow band o2 sensor. Get a good wideband afr gauge that comes with the o2 sensor.

Invest in a vaccum gauge first!

On my car not only am I planning on messing with the carb but the entire fuel system. I ditched the mechanical pump and I'm running an electric with a relay system grounded by an oil pressure safety switch (much like gms of the late 80s early 90s) if I shut the engine off for engine off coasting the pump will shut off. Im also running a fuel pressure regulator. I'm going to set the float to factory spec but I'm going to play with pressure at the carb. Im not counting on that making a difference at all but who knows. It's a carter yf 1 barrel.

Edit: also your only going to see gains from playing with jets rather than idle mixture screws. the idle mixture circuit isnt even used at cruise speed which is where you want your lean condition. the main jet circuit is what you want to modify. only problem with that is your timing curve is set at a certain spot and guess what, if you jet it wayyy lean your going to deal with detonation and chance melting a piston or 8. msd makes an adjustable timing knob where you can retard your timing up to 15 degrees on the fly. it requires driver feedback and constant monitoring but i think it would be fun as heck to have lean burn in a carbed car!! i should pm pgfpro about it he could give some insight on timing a lean burn car.




Also I'm ditching points. I'm 25 and I know how to set these cars up but I really want to take advantage of a stronger spark if I can get it, so I opted for the pertronix conversion. Oh yea and reliability and not having to change them after 20k will be nice too

Take that mechanical fan off and toss an electric fan on via a switch or thermostatically controlled switch. I'm running an adjustable thermo switch.
__________________
Burn lean and prosper \\ //

Last edited by slownugly; 03-17-2014 at 05:21 PM..
  Reply With Quote
The Following User Says Thank You to slownugly For This Useful Post:
dtmerritt (03-17-2014)
Old 03-17-2014, 04:09 PM   #15 (permalink)
Master EcoModder
 
Join Date: Feb 2014
Location: Missoula, MT
Posts: 2,048

Dark Egg - '12 VW Touareg TDI Sport AWD
90 day: 25.81 mpg (US)
Thanks: 165
Thanked 845 Times in 583 Posts
I'm glad you asked this as well. Often I see tuning related to modern cars but these pre-emission cars get to benefit from tuning best for pure economy. Plymouth made a feather Duster in 1976 that with the slant 6 and overdrive manual got great mileage. I wonder how much better a car like that could do with some modern fuel injection and aero mods.
  Reply With Quote
The Following User Says Thank You to Hersbird For This Useful Post:
dtmerritt (03-17-2014)
Old 03-17-2014, 05:13 PM   #16 (permalink)
(:
 
Frank Lee's Avatar
 
Join Date: Jan 2008
Location: up north
Posts: 12,685

Blue - '93 Ford Tempo
Last 3: 27.29 mpg (US)

F150 - '94 Ford F150 XLT 4x4
90 day: 18.5 mpg (US)

Sport Coupe - '92 Ford Tempo GL
Last 3: 69.62 mpg (US)

ShWing! - '82 honda gold wing Interstate
90 day: 33.65 mpg (US)

Moon Unit - '98 Mercury Sable LX Wagon
90 day: 21.24 mpg (US)
Thanks: 1,566
Thanked 3,469 Times in 2,172 Posts
Planes use exhaust temp as the guide for leaning.

http://flighttraining.aopa.org/stude...ls/engine.html
__________________


  Reply With Quote
The Following User Says Thank You to Frank Lee For This Useful Post:
dtmerritt (03-17-2014)
Old 03-17-2014, 09:04 PM   #17 (permalink)
EcoModding Lurker
 
Join Date: Nov 2013
Location: Peoria, AZ
Posts: 9
Thanks: 24
Thanked 0 Times in 0 Posts
I would like a wide band in a few months when my wallet recovers, but for now I purchased a narrow band and the mechanic there will install it for me. I'd rather, but both me and my wife are crippled and have to use scooters to get around. Because of an auto accident I have almost no cartilage in my right hip, add in a stroke on the left side, well I can walk into the bathroom by hanging on (from my electric wheelchair). The stroke made my left hand pretty useless however, so I do what I can, and pay someone to do what I used to.
  Reply With Quote
Old 03-17-2014, 09:08 PM   #18 (permalink)
EcoModding Lurker
 
Join Date: Nov 2013
Location: Peoria, AZ
Posts: 9
Thanks: 24
Thanked 0 Times in 0 Posts
In AZ no emission test is required, IF. You have to belong to an organization and have classic car insurance, it must only be used for car shows and kept in a locked garage.
  Reply With Quote
Old 03-17-2014, 09:09 PM   #19 (permalink)
EcoModding Lurker
 
Join Date: Nov 2013
Location: Peoria, AZ
Posts: 9
Thanks: 24
Thanked 0 Times in 0 Posts
I am thinking EFI.
  Reply With Quote
Old 03-18-2014, 11:07 AM   #20 (permalink)
EcoModding Apprentice
 
KrautBurner's Avatar
 
Join Date: Mar 2014
Location: SUNNY Sequim, Wa
Posts: 238

Cavalier of D00M - '05 Pontiac GTO LS2 T56
90 day: 23.2 mpg (US)

The New One - '10 Toyota Prius II
90 day: 51.55 mpg (US)

Chick Magnet - '91 Geo Metro 3cyl/5sp
90 day: 48.07 mpg (US)
Thanks: 79
Thanked 39 Times in 33 Posts
Quote:
Originally Posted by iveyjh View Post
Maybe I missed it somewhere in the reading of this post nobody ever answered your question about cruising AFR. I find that a ratio of about 16.5 to 18.5 to 1 yields good economy. I don't think you can reach that ratio by just adjusting the idle jets though.
Good luck
that seems aweful lean to me
but all my AFR tuning was done at WOT

thats why I mentioned a EGT (Pyrometer) could be a good safety gauge

__________________
2005 GTO 6.0 V8 (600hp)

1991 Geo Metro 1.0 3/5 base

2010 Prius II (replaced 2001 Tahoe 5.3 V8 April 2014)

1994 F-350 7.3 TurboDiesel (Rollin' Coal)
  Reply With Quote
Reply  Post New Thread


Tags
need advise

Thread Tools




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