MPG fooler - Design phase

[stodg73]

I had someone build me an IAT fooler for my truck, because I don’t really know how to use a relay and soldering gun. I took a run to Denver and back last Friday and here are the results: going to Denver 18.841 MPG without fooler on, coming back from Denver 20.380 MPG. On this trip, I tried to keep my speed consistent, using the cruise control. Everything in my sig. is current. Yes, the propane was on for both runs, that way there was no difference other than the fooler being on. Out here the speed limit is 75 MPH on the highways, so the 1.5mpg difference should be more drastic as the speed limit is lowered.

[Mopar1973Man]

I had someone build me an IAT fooler for my truck, because I don’t really know how to use a relay and soldering gun. I took a run to Denver and back last Friday and here are the results: going to Denver 18.841 MPG without fooler on, coming back from Denver 20.380 MPG. On this trip, I tried to keep my speed consistent, using the cruise control. Everything in my sig. is current. Yes, the propane was on for both runs, that way there was no difference other than the fooler being on. Out here the speed limit is 75 MPH on the highways, so the 1.5mpg difference should be more drastic as the speed limit is lowered.

[stodg73]

Was that the one ISX made for you?

[Rogan]

that's a good increase!

[Heavyd1980]

yes that is a pretty decent increase. so whats next on the agenda in the testing phase?

[JOHNFAK]

I didn't want to toss him under the bus, but yes he did.

WTF ? Where's mine ? Well no Xmas cards for him in 2011 ... Haha Can we just add a resistor permanently to the IAT sensor harness to keep at a steady temp all the time ? Will that work ?

[stodg73]

John, if you put a resistor in there permanently, you would not have your grid heaters working. They are controlled by the IAT. I found this out by leaving the fooler on at 10*, let's just say hard and extended starting. The grid heaters turned off in about 5 seconds, when they normally are on for 20-30 seconds at that temperature.

About the other, I asked, so you have to talk to the builder.

[ISX]

Yeah it really needs a switch in there. Mike just threw a resistor on his and his starts like crap (I heard it on the phone ). They will start without the grids but they wont like it and it will wear the engine out (know this from personal experience skipping the grids on mine, now it relies on them, just like when you use ether, your engine will eventually rely on it since it screws up compression). As far as what to do next with all of this testing, I think it is apparent that it works. I would like to see results of other trucks that are stock or something. The only thing with making them is that I hate wires. It would take 4 wires into the cab to just use a regular switch and resistor and nothing else. For stodg's truck, I used a relay with switch ground so he just stuck the positive on the battery (though he stuck it in the fuse box so it would be fused) and then you only have one wire going into the cab which is hooked to a switch. The other side of the switch you just hook to ground, which means anything in the cab that is grounded will work so you don't have to send a wire back out of the cab. Being a relay, you can switch it up however you like, meaning it doesn't matter which polarity you hook to the relay power wires, as long as one is positive and one is negative, it will work. I need to work on the design a little more. Someone (I think it was JJCTD, cant remember the full name lol) suggested phone cable, which would be very small and so it wouldn't take a gaping whole in the firewall to hook it up. I will have to keep looking at my options.

[stodg73]

ISX, When I redid the wiring, for a LED lighted switch to know when it is on, I used a positive wire from the switch to the relay, using the same hole for all my gauge wiring, and then to a body ground. This way everything is still a 2 wire hook-up, along with the wiring connectors to the IAT. stodg73

[Mopar1973Man]

WTF ? Where's mine ? Well no Xmas cards for him in 2011 ... Haha Can we just add a resistor permanently to the IAT sensor harness to keep at a steady temp all the time ? Will that work ?

That exactly how I'm hooked up but I got to remember to flip the IAT fooler for the high idle on to over ride the resistor in the plug so I do get grid heaters. PITA really... Because if you forget and then flip it on after the key then it too late and the ECM will not fire the grid heater no matter what you try... So you got to fight it and get started... Rather harsh...

[JOHNFAK]

Grid Heaters ??? What are they ?? I live in AZ not MO now ......... remember Yeah it was ISX that told me about the resistor thing a while back (don't want people thinking I am clever) ...... main reason I want to check it out is to see if it helps with my stalling issue ..... I have a feeling it will due to the fueling at certain temps ....... (help not FIX) So ..... until you guys get a design done that you are going to sell (which I think would be a good idea) ....... couple questions 1) ISX what was the resistor type I needed to get ....... what OHM or whatever and what IAT should that keep the truck at (just 1 level permanent for now would be fine). 2) I am *guessing* this will work better for guys in cold climates. My IAT's get up to 110 not too long ...... what are you guys running generally ??? Once you get up to say 110 - having the resistor is not really providing any benefit right ??

[ISX]

Grid Heaters ??? What are they ?? I live in AZ not MO now ......... remember Yeah it was ISX that told me about the resistor thing a while back (don't want people thinking I am clever) ...... main reason I want to check it out is to see if it helps with my stalling issue ..... I have a feeling it will due to the fueling at certain temps ....... (help not FIX) So ..... until you guys get a design done that you are going to sell (which I think would be a good idea) ....... couple questions 1) ISX what was the resistor type I needed to get ....... what OHM or whatever and what IAT should that keep the truck at (just 1 level permanent for now would be fine). 2) I am *guessing* this will work better for guys in cold climates. My IAT's get up to 110 not too long ...... what are you guys running generally ??? Once you get up to say 110 - having the resistor is not really providing any benefit right ??

Mike put in a potentiometer (variable resistor) and is testing to find optimal setting, though I think he is having some issues with the potentiometer he is using (way too high of range resistance). I was wanting someone to use a 5K one so they could change it more precisely, possibly even watch the instant MPG on the scangauge while your driving to find the best resistance setting. But you basically want a resistor around the 2-4k range. 2.2k is what I used in stodg's which should be around 143, 2.7k is 132F (the one mike used before putting in the potentiometer). There is no solid answer as to what the resistance should be, but at least 100F seems to be the key. Hmmmmmmmmmmm, I wonder if you could hook it in with the ECT sensor. Would work perfect, though I think over 200F throws a code? I might know how to get around that.

[SASQCH]

I was wanting someone to use a 5K one so they could change it more precisely, possibly even watch the instant MPG on the scangauge while your driving to find the best resistance setting.

That’s exactly what I am doing using a dpdt on off on mini toggle and a 5K pot. I like the idea of using phone cable to connect it to the IAT location. I really am hesitating on cutting into the wiring to the IAT. I would like to build a plug compatible harness to just plug into the IAT on one side and the harness on the other. Anyone know where I can get connectors?

[Heavyd1980]

Grid Heaters ??? What are they ?? I live in AZ not MO now ......... remember

Yeah it was ISX that told me about the resistor thing a while back (don't want people thinking I am clever) ...... main reason I want to check it out is to see if it helps with my stalling issue ..... I have a feeling it will due to the fueling at certain temps ....... (help not FIX)

So ..... until you guys get a design done that you are going to sell (which I think would be a good idea)

1) ISX what was the resistor type I needed to get ....... what OHM or whatever and what IAT should that keep the truck at (just 1 level permanent for now would be fine).

2) I am *guessing* this will work better for guys in cold climates. My IAT's get up to 110 not too long ...... what are you guys running generally ??? Once you get up to say 110 - having the resistor is not really providing any benefit right ??

Thats what i'm taking about!!!

[Mopar1973Man]

Well just double checking again to see if the there is a change... My weather this morning was -7*F and IAT was hooked up to the sensor (NO FOOLING RESISTOR) I ran my day and topped out at 15.8 MPG with cruise set at 55 MPH and only passed 1 vehicle the whole trip from Home to Donnelly, ID and back home. So the warmer temps are scoring better MPG's for sure. IAT was hovering right around 49-53*F... Cold Air Intakes suck big... Like I said the only change was the resistor was removed and the IAT sensor hooked up and took a down fall in MPG's.

[Heavyd1980]

well thats a good thing then right!?! that proves that the fooler is working and you can continue on with some fine tuning!!! great work Mopar thank you!!!:hyper:

[txmasterplumber]

my '01 is at 325,000 and was on the original thermostat. It was grunting to get to prob. 150*. I figured that it was stuck open, so last Sunday, I changed it out and changed the antifreeze. It's now getting up to regular temp, 180* - 190*. My milage was around 15.3 to 15.8. I think one time I got 16.3. I am running a Smarty set @ 9. I had taken a trip to Houston to see my son one weekend. I had set the Smarty to 0...... man that sucked. I didn't have any power at all ( ok, 0 is half power) but I figured that i'd get better milage at that setting. I got 17.3 . For the trip back, I set it back to 9, and got the same mileage. This was a year ago, when I went to get the dually rear axle for my build. Not a bad deal I think: rear end, 7 stock dually rims and tires ( 2 brand new) $700 , oh yeah, a new set of brake shoes too. Anyway. my mileage had been down since then. Now, since i've changed out the thermo, with the temps up, I should be getting better mpg's, right? ...... please post some pics of the set up with the resistors, or maybe a schematic drawing, so us plumbers can understand, please!!!!!!

[Mopar1973Man]

Anyone know where I can get connectors?

Right here...

http://www.casperselectronics.com/store2/

[Mopar1973Man]

Well once again the warm air wins the battle... Today I re-installed my winter fronts, up the IAT to 140*F like ISX suggested and ran for McCall, ID with morning temps as low as 17*F and my return trip was barely 30*F. Then got home for a short break and head to another job in Riggins, ID and then return home bucking a 10-20 MPH wind home... Hit the drive way with 21 MPG... High mark of the day at 23 MPG... Cruise set for 55 MPH... There is just no two ways about it warm air physically and logic hit better numbers all the way around... Sure gives new meaning to CAI's... They are not what there cracked up to be...

[Mopar1973Man]

my '01 is at 325,000 and was on the original thermostat. It was grunting to get to prob. 150*. I figured that it was stuck open, so last Sunday, I changed it out and changed the antifreeze. It's now getting up to regular temp, 180* - 190*. My milage was around 15.3 to 15.8. I think one time I got 16.3. I am running a Smarty set @ 9. I had taken a trip to Houston to see my son one weekend. I had set the Smarty to 0...... man that sucked. I didn't have any power at all ( ok, 0 is half power) but I figured that i'd get better milage at that setting. I got 17.3 . For the trip back, I set it back to 9, and got the same mileage. This was a year ago, when I went to get the dually rear axle for my build. Not a bad deal I think: rear end, 7 stock dually rims and tires ( 2 brand new) $700 , oh yeah, a new set of brake shoes too. Anyway. my mileage had been down since then. Now, since i've changed out the thermo, with the temps up, I should be getting better mpg's, right? ...... please post some pics of the set up with the resistors, or maybe a schematic drawing, so us plumbers can understand, please!!!!!!

Just unplug the IAT and stuff a resistor into the plug...

Simple enough that's all I'm doing...