Well gang... I've been playing with theories and ideas for long enough now its time to put them into a design and see if it actually works. We all know the 24V's seem to take a good tumble in MPG's as the winter sets in well ISX proved that with the 12V engines with static timing that MPG's don't change. Well if you look at it the only thing that could be tossing this out the window is the IAT sensor on the 24V is changing the VP44 performance. Most know that colder air produces better HP/TQ because colder air is denser and requires more fuel to keep balanced. Well if you reverse this and warm the air (in theory) the VP44 should retune and burn according to the manifold temp. So what I've done tonight is fished through my resistor pile and found 3 I'm going to use for test candidates. Orange - White - Red - Gold = 3.9K Ohm = 116*F IATRed - Violet - Red - Gold = 2.7K ohm = 132*F IATRed - Black - Red - Gold = 2.0K ohm = 148*F IAT So now tomorrow I'm going to pull 3 test runs on the same piece of highway... Seeing if the highier the IAT temp increases the MPG or not... I'll can give you something to think about... Grid heaters are NOT controlled directly by the IAT... With the 2.7K Ohm resistor in place before even starting the grid heater still where hitting as normal. So there is more to the grid heater that the IAT temps... ... On the cutting edge again...

Done it again...

Mild weather 30-40*F, No wind, Cruise Set @ 55 MPH, IAT 140*F (Forced), Winter front (installed) 22 MPG on 40 mile round trip.

I left today to get a couple gallons of paint for paint a room. So I headed to New Meadows, ID set my cruise for 55 MPH and took my time. On the way up canyon I was doubtful about numbers because I was watch 600-800*F EGT's but still 3-5 PSI boost. But once I made it ot the flats in Meadows Valley it fell 2-3 PSI of boost and floating 400-600*F. I was gain number rapidly. Once I hit New Meadows I had 16 MPG even after climbing the grade out. Now got my paint stopped in a friends place BS for a bit and came home set the cruise for 55 MPH home again. I'm all smileys because now I know the warmer air trapped under the hood is actually helping!

Sorry if I missed it but what resistor are you using Mike? I can plug the truck in overnight when it gets cold so it will start good in the morning and it was 65 here today so it should be fine during my daily travels. Also do it throw any codes? This is really amazing because my average is 16mpg.

Right now I'm running a rheostat plugged into the IAT plug. This allows me to adjust and try to fine tune the IAT temps to get the most. So after yackin' with ISX and talking theories I went back up with temp to try 140*F IAt and this time added the winter fronts to feed warm air at the engine. So if your going to follow along with this you would lose your grid heater in the morning. But it throws no codes because the IAT temp is legit number so the ECM assumes its true. But basically if you want a toggle switch design you would build the ECT fooler basically but use IAT plugs on it then use the proper resistor for the temp you want... (Look back at the first few posts)

I guess I will try the 2.7 and see if it helps.

I guess I will try the 2.7 and see if it helps.

Now remember driving style is 80% of this number... So if you think it give you ability to be heavy on the throttle it doesn't... I'll get the ohm value off mine rheostat in the morning...

I think this is really great. I was thinking toggle switch, like everyone else. I had the same concerns about the added wires through the firewall but the relay is an interesting bump forward. Like someone reflected, too bad one must remember to switch back if one wants the grid heaters for starting. (In other words, "not wife friendly!" (Unfortunately, wife subscribes to the plan that what is mine is mine and what is yours is mine also. If you don't think so, start messing in her underwear drawer! LOL! Or better yet, try to use HER Subaru.) Back to the original topic, You guys are way more clever than I am these days... what about using the correct IAT sensor to trigger the intake grids... When the intake grids shut off, triggers the IAT fooler. If it picked up 1 mpg in cold weather, every guy would have to have one. You can sell them & we'll split the royalities and we can all move to a location where the grid heaters never run!Russ

I think this is really great. I was thinking toggle switch, like everyone else. I had the same concerns about the added wires through the firewall but the relay is an interesting bump forward. Like someone reflected, too bad one must remember to switch back if one wants the grid heaters for starting. (In other words, "not wife friendly!" (Unfortunately, wife subscribes to the plan that what is mine is mine and what is yours is mine also. If you don't think so, start messing in her underwear drawer! LOL! Or better yet, try to use HER Subaru.) Back to the original topic, You guys are way more clever than I am these days... what about using the correct IAT sensor to trigger the intake grids... When the intake grids shut off, triggers the IAT fooler. If it picked up 1 mpg in cold weather, every guy would have to have one. You can sell them & we'll split the royalities and we can all move to a location where the grid heaters never run! Russ

I think I know a way to make it completely automatic.. All you would have to do is install it. It would also fix another problem with the grids running on a warm engine. I am sure you noticed if it is cold out and you go to a drive-thru and shut the truck off, it will run the grids when you restart. The grids would run like normal any time the engine is cold.

I think I know a way to make it completely automatic.. All you would have to do is install it. It would also fix another problem with the grids running on a warm engine. I am sure you noticed if it is cold out and you go to a drive-thru and shut the truck off, it will run the grids when you restart. The grids would run like normal any time the engine is cold.

So how are you going to do this? Sounds like a winner if you can make it work.

I'm think guys I'm thinking I trying to figure out different lead on the truck to trigger relays and such... I smell smoke... Oh I'm thinking hard...

Don't blow the brain up. We all need the input!

Now remember driving style is 80% of this number... So if you think it give you ability to be heavy on the throttle it doesn't... I'll get the ohm value off mine rheostat in the morning...

Mike, it doesnt seem to matter how I drive this thing I just cant get any kind of mileage. The best I ever got was 17.9 around Christmas and I dont know how it did it.

Mike, it doesnt seem to matter how I drive this thing I just cant get any kind of mileage. The best I ever got was 17.9 around Christmas and I dont know how it did it.

What kind of mods done to the truck?

I am working on getting a tripple disk torque convertor and I think/hope that will help alot. I have 150hp injectors, edge comp, fass 150, 4 inch exhaust and slipping convertor. I usually run on 3x5 but lately have been running on 5x5 trying different things. I run 265/70/17 bfg street tread tires and 3.54 gears.

I double checked your tire size and your right on for stock size (off by 1 rev/mile 0.1%). As for the torque converter that might just be part of what's biting you. Other than that its all about driving habits... :shrug:Might try the fooler and see how it works out. Shoot! I didn't get the ohm reading...

Don't blow the brain up.

We all need the input!

hahahaha - no kidding

--- Update to the previous post...

I am working on getting a tripple disk torque convertor and I think/hope that will help alot. I have 150hp injectors, edge comp, fass 150, 4 inch exhaust and slipping convertor. I usually run on 3x5 but lately have been running on 5x5 trying different things. I run 265/70/17 bfg street tread tires and 3.54 gears.

Don't think the 3x will help you much unless your slipping a lot now. Its a fluid coupling until lockup ..... so I think only adjusting the stator etc to a different stall will help slightly. Honestly ..... I'd try switchng out your injectors from 150 to stock .......... just to try ....... I would think it would be hard to control that.

Beyond that ..... smaller tires maybe ..... and you could try a different programmer ....... just for comparison - make sure your getting all the timing you want/need etc

But seriously ...... I'd look at the injectors as #1.

I just installed a 10k ohm potentiometer in the cab and ran wires out to the IAT plug. I have found the lowest I can fool the IAT is to only 77f with the 10k pot.. I should have went with a 20k pot. to get full temp range from -40 to + 300f. This will be a good start anyways. I won't have any hard data until the snow/salt is off the road, as I don't winter drive the truck, it's primarily my camper hauler. I'm excited to do some testing, it will be a long wait.

I just installed a 10k ohm potentiometer in the cab and ran wires out to the IAT plug. I have found the lowest I can fool the IAT is to only 77f with the 10k pot.. I should have went with a 20k pot. to get full temp range from -40 to + 300f. This will be a good start anyways. I won't have any hard data until the snow/salt is off the road, as I don't winter drive the truck, it's primarily my camper hauler. I'm excited to do some testing, it will be a long wait.

You don't want a colder temp, you want hotter. But you can only go to 200F, over that I think it throws a code. Ideally you want a 5K POT, as you will be able to dial in the temp easily. 10K is ok, 20k would be tough. Mike is using a 50K and can barely hit the temp he wants because the temp he is shooting for is in the 2K range which is very hard to hit on something with a 50K range, but something with a 5K range would make the 2K window much bigger and easier to hit. I don't know what the ohm for 200F would be, but I am thinking 1.5K.

Like ISX said you want it to see higher IAT temps. Also you need to use a winter front as much as possible. The actual warm air under the hood actually help the MPG numbers. Where colder air tends to degrade the out come...

I should have my fooler setup in a couple of weeks. Thanks to Mike I ordered a 12" IAT extension cable from Casper electronics. http://www.casperselectronics.com/store2/product_info.php?products_id=1503. Then I went to the local electronics store and found a double pole double throw miniature toggle, a 5K ohm potentiometer with knob., and a length of 3/c 18 AWG (0.824 MM2) type SVO cable. I am going to cut the + wire in the extension and connect it to one of the wires in the cable (white) and the other side of the cut wire in the extension to the second wire in the cable (green). Then connect the third wire in the cable (black) to the negative wire in the extension without cutting it. On the other end of the cable inside of the cab I will connect wire one (white) and three (black) to each of the two pols on one throw of the toggle (so I can use the IAT like normal). then on the toggle I will connect the + wire pole (white) of the normal throw to the first poll on the second (IAT fooler) throw (so one poll on each throw is connected to the + (white) wire). Then from the other poll of the second throw (green) I will connect to the potentiometer. The other connector of the pot will get connected to the third wire in the cable (black) that connects to the negative wire in the extension. With this setup I will have a T connector to connect to the IAT and the factory harness, A toggle in the cab to go between the IAT fooler and the normal IAT operation, and an adjustable potentiometer to set the IAT reading in fooler mode using my SG II IAT reading. I hope this will be a plug and play unit when I am done with it. When the extension comes in and I start to assemble this unit I will take pictures, make a wiring diagram, and keep a log so if anyone else wants to build one they can. Jim

Originally Posted by ISX You don't want a colder temp, you want hotter. But you can only go to 200F, over that I think it throws a code. Ideally you want a 5K POT, as you will be able to dial in the temp easily. 10K is ok, 20k would be tough. Mike is using a 50K and can barely hit the temp he wants because the temp he is shooting for is in the 2K range which is very hard to hit on something with a 50K range, but something with a 5K range would make the 2K window much bigger and easier to hit. I don't know what the ohm for 200F would be, but I am thinking 1.5K.

I want the truck to have the ability to start and run run in cold weather, so I need the IAT to see approx ambient temps. and I can't do that with even a 10k pot as I said earlier lowest temp the 10k pot can produce is only 77f , I suspect with a 5k pot the grid heaters may not even come on in cold weather. For testing I think I will start at 120f and then work my up. good to know that it may throw a code if I go to high. --- Update to the previous post...

Originally Posted by SASQCH I should have my fooler setup in a couple of weeks. Thanks to Mike I ordered a 12" IAT extension cable from Casper electronics. http://www.casperselectronics.com/st...oducts_id=1503. Then I went to the local electronics store and found a double pole double throw miniature toggle, a 5K ohm potentiometer with knob., and a length of 3/c 18 AWG (0.824 MM2) type SVO cable. I am going to cut the + wire in the extension and connect it to one of the wires in the cable (white) and the other side of the cut wire in the extension to the second wire in the cable (green). Then connect the third wire in the cable (black) to the negative wire in the extension without cutting it. On the other end of the cable inside of the cab I will connect wire one (white) and three (black) to each of the two pols on one throw of the toggle (so I can use the IAT like normal). then on the toggle I will connect the + wire pole (white) of the normal throw to the first poll on the second (IAT fooler) throw (so one poll on each throw is connected to the + (white) wire). Then from the other poll of the second throw (green) I will connect to the potentiometer. The other connector of the pot will get connected to the third wire in the cable (black) that connects to the negative wire in the extension. With this setup I will have a T connector to connect to the IAT and the factory harness, A toggle in the cab to go between the IAT fooler and the normal IAT operation, and an adjustable potentiometer to set the IAT reading in fooler mode using my SG II IAT reading. I hope this will be a plug and play unit when I am done with it. When the extension comes in and I start to assemble this unit I will take pictures, make a wiring diagram, and keep a log so if anyone else wants to build one they can. Jim

I like your idea about the toggle switch to make the IAT operate like factory mode. My 10k pot or likely ISX's 5k pot would work as well.