Congrats to COZX2 on the 100+ MPG fill!

[CO ZX2]

I list my mods and my estimate of the effect they have had on my FE. This is not intended to be a guide for anyone, just my statement of what I have done and how they relate to my car. A little hard to give completely separate figures for each mod as some are intertwined and depend on others for best results. I will use 43 mpg as a baseline as that was my best measured tank in 4 years before any mods and normal driving. Note that 43 mpg is considerably over EPA before any mods. I have evaluated a number of mods that didn't pass the test. No gain, they are not here anymore. Keeps me from accumulating a bunch of useless mods.

1. I will start with the first 2 mods I ever did. I completely covered and sealed the grille area and installed quickie rear skirts, also sealed. The first tank with these mods produced 11 mpg over my previous best. There was some engine on neutral coasting involved here but not to a large extent. Much later I found that these mods also were effective in reducing negative pressures at the rear of the car, something I was not fully aware of when the mods were first installed. Shortly afterwards is when I joined GasSavers.

2. ScanGauge II woke me up considerably. Changed my driving forever. Very valuable in making me aware of real time mpg and other engine functions that would lend themselves to improvement. I will group engine off neutral coasting and pulse and glide (my idea of a true glide is engine off in neutral) in with SG. I believe these items, developed over time, have produced (conservatively) 20 mpg for me.

3. I will list the following items together because they are so intertwined and dependent on each other. Combined I estimate 22 mpg benefit from items below.

a. Partial belly pan, bumper to front tires and under engine (placed my engine temps and AIT temps into a more consistent efficiency range, especially in frigid weather). I have recently discovered the belly pan also has a profound effect on my measured wake pressures at the rear of the car. Additions to this pan proved detrimental to wake pressures and were promptly removed. The pressure/flow gauges have enabled me to identify and correct turbulence all around the car. I have managed to reduce the negative pressures at the rear of car to near zero. Sources that I have read cite that negative pressures and turbulence at the rear may produce as much as 85% of total aero drag. Have also read that a Ford Taurus pushes 6 tons of air per mile out of the way at 60 mph. These are astounding figures.

b. Wheel spats(4) to deflect air around tires. Front fender skirts. Air dam and recent extension of it. I have recently realized the cumulative effect of these mods on the wake pressures measured with the pressure/flow gauges I acquired in February. These gauges have made these mods' effects easier to identify and explain than I was able to do before.

4. I will group the following miscellaneous items together to try and shorten this report a bit. I consider each of these mods stand-alone that have their own distinct advantages. Combined, my estimate is 15 mpg benefit as I use them optimally.

a. Cold startup aids, engine block heater, coolant heater, engine compartment insulation.

b. Alternator off switch.

c. Fairly recent transmission gear change reducing my engine rpm 7%. I will mention that I have another home/modded gearset that will lower my engine rpm an additional 22%. Have not used these yet. I have a camshaft in the works as a complement to this lower rpm range. I am fairly certain camshaft will be needed to provide additional torque at the lower engine speed. These items will probably constitute my next major attempt at increased mileage.

d. Also recent, ECU fuel trim range adjustments.

e. More recent, select disconnection of knock sensor to allow additional ignition timing. Especially helpful in my quest of better upgrade mileage.

f. Injector kill switch mounted on gearshift lever. Instantly kills engine without fumbling with ignition switch. Everything else stays on that ignition switch controls. No fuel can be consumed when this is switched off. Makes EOC infinitely easier. I can shut the engine down, slide into neutral, turn the switch back on and bump start when ready by putting back in gear, all while keeping my eyes on the road.

g. B.F. Goodrich TA Touring tires with real decent LRR rating. I use 60 psi in all 4 tires, wear patterns look great. Spun smooth wheel discs.

h. I keep thinking of one more thing I should mention. I have a manual switch for my radiator fan, I have not had it turned on at all in the last 8 months. I have found that my engine is more efficient at temps 210-225 degrees. Rejected heat is lost energy, I strive to retain as much as practical. A great help when EOCing in keeping engine temps from dropping too far.

Hope this is an adequate picture of my mods and what they did for me. They are here for anyone to consider as they see fit.

[minic6]

Whew lots of work for alot of gain. Thanks for sharing. Curious is the gear set changes your own work or did you find available pre built parts.
Engine running hotter is a new concept to lots of people. Remember the days of lowering the thermostate temp. We were going the backwards to todays metods. Getting the car up to temp. fast is the way to go. Most new cars are built that way.
Also your fan mod. is of intrest. Corvettes now have a 98% duty cycle fan that comes on only as needed as fast as needed. Suspect lots of veh. use this today. Thanks again for sharing. I think your supporters out weigh your skeptics. Way to go!

[CO ZX2]

Originally Posted by minic6

Whew lots of work for alot of gain. Thanks for sharing. Curious is the gear set changes your own work or did you find available pre built parts.
Engine running hotter is a new concept to lots of people. Remember the days of lowering the thermostate temp. We were going the backwards to todays metods. Getting the car up to temp. fast is the way to go. Most new cars are built that way.
Also your fan mod. is of intrest. Corvettes now have a 98% duty cycle fan that comes on only as needed as fast as needed. Suspect lots of veh. use this today. Thanks again for sharing. I think your supporters out weigh your skeptics. Way to go!

Thanks, minic6, I posted my gearset info into a thread started by another member. You will find 3 of my posts there:
http://www.gassavers.org/showthread.php?t=3094

I kyped the idea from my friend Tom, an engineer in Michigan. There is a link to his site that shows great pics. Made from stock gears from another Escort trans. I paid $200 for precision grinding of the gears, $55 for the used trans and my brother did the welding. Custom cut gears would probably cost more than my car is worth. Hope all this info is of some use.

[88HF]

have you considered any weight reduction? Also, how do your pressure gauges work, that must be what the black box is in your photos?

[CO ZX2]

Originally Posted by 88HF

have you considered any weight reduction? Also, how do your pressure gauges work, that must be what the black box is in your photos?

I have thought of weight reduction, but not seriously. I do not want to rip my car apart which would be necessary for any meaningful reductions.

My gauges direct read air pressure as the car is moving. I read the gauges inside the car at 60 mph. All windows and vents have to be tightly closed and fans turned off in cabin. Assists me in spotting problem areas of turbulence and flow. Gauges are zeroed to atmospheric pressure at rest. I use 3/16 in. plastic tubing taped to various spots on the car. I have started using all 6 at once to minimize the place tubing, start, accelerate to 60 mph, stop, change tubing position then repeat over and over. Saves a lot of time and gas. Recently started testing on my regular driving trips instead of special test only sessions. What can be learned from these gauges has been my biggest discovery ever.

[88HF]

so you are looking for pressure differences within the cabin?

[CO ZX2]

Originally Posted by 88HF

so you are looking for pressure differences within the cabin?

I can but have not. I am using only to pick up pressure readings on the outside of the car at this time. Gauges compare outside pressures to the atmospheric pressure inside the cabin. I could use the gauges to read the pressure effect of window(s) down, vents open, fans on, etc.

My main focus has been to reduce the negative pressures at the rear of the car. As the car moves forward at speed, punching a hole in the air, vacuum (if you will) forms at the rear because the punched hole does not fill in at the rear as fast as it is occuring. This created vacuum is trying to pull the car backwards. Experts cite 85% of total aero drag is caused by this vacuum and turbulence at the rear of the car.

[mrmad]

Have you found that the front air dam on your car decreases the pressure under the car? Before banned, F1 cars used to have skirts to cause downforce (and probably increased drag) to allow higher cornering speeds. I have seen several cars on Gassavers using air dams on the front or lowering the car, but have thought that it would be better to improve the flow of air under the car then try to reduce the amount of air flowing under the car.

[CO ZX2]

Originally Posted by mrmad

Have you found that the front air dam on your car decreases the pressure under the car? Before banned, F1 cars used to have skirts to cause downforce (and probably increased drag) to allow higher cornering speeds. I have seen several cars on Gassavers using air dams on the front or lowering the car, but have thought that it would be better to improve the flow of air under the car then try to reduce the amount of air flowing under the car.

Have not got around to checking the undercar pressures much. With the reduction in negative pressures at the back of the car, that has to outweigh most all other factors. With no skirts at the body sill I would not expect to see significant low pressures underneath. I will test it more in the future.

Has any of this given you any ideas for you own car?

[88HF]

I've been trying to figure out how to wire up switches to interrupt my injector signal grounds which appear to run from the injectors up to the driver's side near the injector resistor. I'm thinking the brown, red, light blue, and yellow need to be cut into and a switch added there. I also think the green/white wire to my alternator may be the one to interrupt which signals the alternator that the battery is charged. I'm not really up for the aero mods yet. I have to make sure it looks alright, but most importantly that it won't fly off. I don't understand how you route those little tubes to outside the car without creating some kind of air leak.