dejavouxdoux

How can you tell you're getting better mileage from an EGA? There are so many factors to getting better mileage that you have to try one at a time to see what really works. Here's what I already know works.

Tire pressure. Keep your tires inflated to the max tire pressure listed on the tire. This reduces friction and makes your tires last longer. Every two pound decrease in pressure results in an 8 degree increase in temperature and greater friction.

Remove the ethanol from your fuel. Here's a great way to accomplish this for under 20 bucks.

http://www.beginyourdreams.com/no-ethanol.html

Buy an Ultra Gauge for under a 100 bucks so you can monitor all your sensors. I doubt if the mileage calculator is accurate but it at least gives you a benchmark to adjust your driving habits.

http://ultra-gauge.com/ZC/index.php?...c53em01vmip9t5

E10 (and soon E15) will make your PCM/ECU think you're running lean and add an additional amount of fuel. So, you probably can use an O2 sensor spacer to trick the computer into thinking there's less O2 in the pipe faking a rich condition. But again, you have to have a way to monitor the sensor output before and after the installation. The Ultra-Gauge EM Plus can monitor 78 different values including O2 sensor output. Check it out on this page.

http://www.ultra-gauge.com/ultragauge/TEN/gauges.htm

Here's some great info on how the ECU determines the correct AF ratio:

http://www.ultra-gauge.com/customer_...php?article=29

The last thing I'll mention in this reply is that ethanol has an addition oxygen atom that also adds to the lean condition sensed by the O2 sensor. The molecular formula for ethanol is C2H6O.

Here's the sensor spacer I'm going to try. It allows you to use different openings like jets to adjust the O2 volume sensed by the sensor.

http://www.iaperformance.com/product...oducts_id=3100

I'll keep everyone posted when I have some data.

Later, gator.

Just call me Sean

iTrader: (1)

Thanks for responding to a three year old thread.

Warlockk

Wow I don't know where to begin to point out the error in that. I guess I'll just mention that the entire theory predicted on the idea the the system is set rich is a problem. The system is always set as lean as possible to create lower emissions.

sdmartin65

Spacing the 02 out of exhaust stream wasn't a good idea, didn't take long to get a lean misfire.
Thanks for the replies.

dejavouxdoux

I believe that used to be the case but several articles I've read claim that a lean factory setting is no longer necessary. This is because almost all of the gas we use now contains ethanol. Ethanol allegedly burns cleaner and contains additional oxygen. The molecular formula for ethanol is C2H6O and the Stoichiometric AFR for 15% ethanol is 13.79:1. Claims are that when you burn ethanol the computer thinks you're running lean and adds more fuel to the mix which results in less mileage. I'll be able to give you more info when I get my Ultra Gauge and I can look at the data with and without ethanol fuel.

dejavouxdoux

Just curious, how long was your spacer? They make several different lengths.

sdmartin65

Probably spaced it back 3/4", but it also surrounds it with aluminum. The spacer had to be widened out with a drill bit to fit the 02.

Warlockk

Ok fortunately before I began to lay into your post again I re read it and realized I was combining your post with another. Most if what you are saying makes sense. However the computer still sets the air/fuel ratio to the leanest possible setting. It doesn't care weather the oxygen comes from the air or the fuel. You could run liquid oxygen and have no air intake and the o2 sensors will still set to the same ratio for oxygen. Newer systems with flex fuel programmed into the system will measure mass air flow and fuel intake vs o2 outputs and determine the type if fuel used then advance timing to maximize the potential of ethanol. That is its greater resistance to detonation. Some variable intake and direct injection cars can actually increase compression when running ethanol to increase power output. But our cars were designed long before that technology was common on the market. Those that used it for racing fuel designed custom programs and fuel tables obviously. The article about separating the ethanol in my opinion is a complete waste of time unless you are using it on a vehicle which needs to be stored for pong periods like a collector car, boat or other equipment. Ethanol doesn't store well and can damage fuel lines and pumps, but in a vehicle you would be hard pressed to find a difference that is worth collecting and pouring fuel back and forth. Not to mention the risk of water contamination in the fuel is far greater than any gain. Then adding octane booster will only in increase carbon deposits in the cylinders and decrease performance on a properly running engine at stock compression. Lower octane burns more energetically producing more power. When compression is increased it can burn so energetically that it explodes on more than one front causing ping. So we use high octane on high compression engines because it burns slowly. On a low compression engine in our trucks high octane burns too slowly and doesn't complete the burn in time. So raw fuel is left cooling the cylinder. The cylinder tests too cool and the unburned fuel turns to carbon deposits creating more problems until there is valve damage. Since not all the fuel is burning you loose power and mpg. I still don't see why anyone wants to attempt to throw off the o2 sensor. It will just mess up the vehicles performance. It was designed over a lot of testing. The only real way to improve the fuel control is with a gas analyzer and a dunk and some runs on a track. Throwing a spacer on it ain't going to cut it. Rule #2 of modification is if it could have been done for less than a buck and produced gains why didn't the factory do it?

dejavouxdoux

I'm not gonna get into a big debate with anyone about this but let me make just a few more comments. I'm not sure where you get your information, but if it comes from the Net, it's always questionable. I've been removing ethanol from fuel for about six months and I haven't had a single problem. It's so easy a 5th grader can do it and it only takes about 10 minutes. And from what I've read (on the Net ??), it's the ethanol that causes the carbon buildup in your combustion chambers. The main ingredient in octane booster is methanol, which is a clean and cool burning fuel so I can't see where you would have any problems. When you take ethanol out of the mix you lose octane. I changed my original post because I can't find the article and I may have possibly misinterpreted something. I'm really not sure about 4 wheelers but with motorcycles the ECU always tries to achieve the Stoichiometric AFR. I know this because I was an instructor at MMI in Phoenix and took several courses about EFI theory and operation in my 4 1/2 years there. Thanks for your input.

sdmartin65

I would disagree with "if it's cheap the factory would do it". Not exact quote but anyway. The factory always builds a safety factor into engine operation and have to account for sound levels and so forth, so there is some room for improvement of performance.