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...

What is the Casper part number for the extension harness, please?

www.casperselectronics.com MAT Air Temp Sensor Extension 12" Part # 109017 Jim

What is the Casper part number for the extension harness, please? I am confused about the resistor value desired. I'm looking at the chart: IAT Sensor Resistance Values Temperature Resistance 13°F 56K ohms 30ºF 40K ohms 32ºF 30K - 36K ohms 76ºF 13K ohms 77ºF 9K - 11K ohms 81ºF 6.87K ohms 122ºF 3K - 4K ohms 130ºF 4K ohms 167ºF 600 -675 ohms 212ºF 600 - 675 ohms http://mopar.mopar1973man.com/cummins/2ndgen24v/iat-sensor/iat-sensor.htm Am I missing something?

Those are rough values I got from another web site long ago... Here is a few I've test for sure... Orange - White - Red - Gold = 3.9K Ohm = 116*F IAT Red - Violet - Red - Gold = 2.7K ohm = 132*F IAT Red - Black - Red - Gold = 2.0K ohm = 148*F IAT

So have you noticed improved mpg's or am I the odd man out who didn't see any improvement?

Havn't driven it enough to get a mpg increase number. However, with the engine at operating temp in neutral at idle, the gph on my SG II shows 1.48 GPG using the factory IAT. When I switch it over to the IAT FOOLER and the pot is set to 140* IAT readout for the IAT, the gph drops to 1.33. That is a .15 GPH savings at idle. That is a hair over 10% gain. I'm hoping that holds true throughout the operating range. The couple of short runs I have done indicate that may hold true but it's difficult to get an accurate reading on the instant MPG readout on the SG II because it is always changing a little adjusting for the road and driving conditions. (slight grade, wind, other vehicle drafts, etc.) Jim

I will be travleing this weekend with the 2.2k resistor in and will get back with you on if it gained me any mileage or not.

Here you go... I did the testing of several common value resistors and got the IAT temp values for you.

I can tell you that the 3rd band will always be RED

And the first band should never be BLACK or BROWN

Values used for IAT Fooler in High Idle Design

13*F - 56K Ohms - Green/Blue/Orange

26*F - 39K Ohms - Orange/White/Orange

Tested Values for MPG Fooler

87*F - 7.4K Ohms - Violet/Green/Red

91*F - 6.8K Ohms - Blue/Grey/Red

100*F - 5.6K Ohms - Green/Blue/Red

107*F - 4.7K Ohms - Yellow/Violet/Red

112*F - 4.3K Ohms - Yellow/Orange/Red

119*F - 3.6K Ohms - Orange/Blue/Red

123*F - 3.3K Ohms - Orange/Orange/Red

127*F - 3.0K Ohms - Orange/Black/Red

132*F - 2.7K Ohms - Red/Violet/Red

143*F - 2.2K Ohms - Red/Red/Red <- Currently using

148*F - 2.0K Ohms - Red/Black/Red

Unsafe Values - Don't Use! - Documenting values for tesing purpose!

163*F - 1.5K Ohms - Brown/Green/Red

173*F - 1.2K Ohms - Brown/Red/Red

184*F - 1.0K Ohms - Brown/Black/Red

Also the IAT page was update with this information...

http://mopar.mopar1973man.com/cummins/2ndgen24v/iat-sensor/iat-sensor.htm

--- Update to the previous post...

HTML page created to give more exposure to the theory and hopefully bring ther into trying the idea...

http://mopar.mopar1973man.com/cummins/2ndgen24v/mpg-fooler/mpg-fooler.htm

This MPG fooler... could be huge benifit. My winter MPG drops so steeply... I'll bet I'm getting 15s compared to summer 18s to 19s. This could pay for itself quickly with the high (and rising) cost of fuel. I could not find that IAT harness on Caspers Electronics looking under Dodge. I entered that number & the harness came right up. I now have my IAT extension harness on order. Thankyou!!I have a DPDT switch, 2.2K resistors & an unused projects box waiting to be used...

Still holding good MPG numbers at 21 MPG on a 11*F day... Cruise set at 55 MPH...

Well it didnt work for me. My ultra gauge stays between 17.8 and 19.5 mpg this entire tank and it came out to 15.9. The weather has been between 45 adn 70 with mixed city and hwy driving and I just cant break that mark. I sure was hoping this 2.2k resistor helpedc but all it did was make my ultra gauge read off higher than usual.:banghead:

Well it didnt work for me. My ultra gauge stays between 17.8 and 19.5 mpg this entire tank and it came out to 15.9. The weather has been between 45 adn 70 with mixed city and hwy driving and I just cant break that mark. I sure was hoping this 2.2k resistor helpedc but all it did was make my ultra gauge read off higher than usual.:banghead:

There must be something to the fooler and the edge comp that makes it work, but not sure what. Stodg got results with his smarty. Mike, did you ever hand calculate it?

The $64,000 Question is whether this Fooler stands up at the fuel pump. All these electronic estimates can not replace the odometer & the fuel pump. I think we're on to something but we'll not know for sure until it is hand calculated over several tankfuls. Can you tell, I'm getting psyched?

There must be something to the fooler and the edge comp that makes it work, but not sure what. Stodg got results with his smarty. Mike, did you ever hand calculate it?

Can't afford to fill the tank... $20 here... $40 there... I'm still logging the fuel data but waiting for the money to fill up. I know my calibration was good as of the start of winter (Nov-Dec) and the only thing changed on the truck is the IAT... Like I've got to head to town soon in the next few days to put another 20-40 buck in it...

Can't afford to fill the tank... $20 here... $40 there... I'm still logging the fuel data but waiting for the money to fill up. I know my calibration was good as of the start of winter (Nov-Dec) and the only thing changed on the truck is the IAT... Like I've got to head to town soon in the next few days to put another 20-40 buck in it...

You're telling me you have been relying on the scan gauge all this time and have never hand calculated it?

Mike, what is this gauge? Brand?

[ATTACH=CONFIG]2322[/ATTACH]

Here you go... Now why would I try filling a tank here locally when the local diesel price is $4.089 in New Meadows, ID and $4.109 in McCall? Now in I nickle and dime time I make another trip down to Boise, ID its much less... Right now roughly figuring it would cost me $102.26 to fill up... I just don't have that much in my pockets...

Mike, what is this gauge? Brand?

[ATTACH=CONFIG]2322[/ATTACH]

Pana-Pacific - That particual gauge is no long made... They changed the design...

The whole part of this entire thing that I have been questioning is consistency. We have to get hand calculated numbers. It's hard enough knowing how a 24V operates without owning one, getting information that isn't solid just makes it even worse. I would do it myself but I obviously can't. I already have seen a lot of things that don't seem consistent to me in this thread that I have been trying to make sense of but it isn't easy to do. The only solid info I can believe right now is what whitelightning is saying. I think stodg hand calculated and saw a gain but I am not sure if he did that or not. It's inconsistent stuff like this that gets internet phenomenons started. For this thing to work, we have to get solid info to know for sure Here you go txplumbermaster. http://forum.mopar1973man.com/threads/1922-Temp-Gauge...?highlight=gauge

That's why I got trip to trip basis... Clearing the SGII and record for a single trip... Also my problem is my odometer is off by 0.5 of a MPH slow so my hand numbers typically come out a 0.2 ot 0.3 lower than SGII because of this small error. Then if I happen to haul a load of firewood for friend in New Meadows, ID again that would skew the entire tank (hand clac). Or if I happen to drive up in the mountain to a buddy's place 11 miles back. (Roughly 4-6 MPG the whole way up the 11 miles). So in order to keep clean data I've been using the same test route back and forth to McCall shopping. Because I drive the same way there and back everytime. It involves traveling from 2,800 ft elevation to 5,200 feet in McCall, ID speed zones ranging from 25 MPH in the cities, 45 MPH on the grades, 55 MPH on the highways (Posted 65 MPH).

Mine were hand calculated. I don't have the numbers in front of me right now, but when I get them, I will post them.

I remember your numbers Stodg. You got a gain out of it. Leads me to believe it does help but not everyone, possibly. If we knew what it did we would have a better idea. One thing I thought about last night was that my timing was at 16 or 17* (maybe even higher) and then I went back to 13.5 (stock) and I get the same mileage, which makes me think timing isn't that detrimental, though I do wonder if it is more detrimental on something with higher injection pressures.

Well there is a lot of variables... Like if I kick it up to 65 MPH from 55 MPH I can kill off all my gains to 18-19 MPG. So driving style has something to do with it. Also in my area of Idaho there is no traffic light just stop signs. So its not like I sit in stop and go traffic. Like some of the runs and things I didn't report because knowing I was in a hurry and drove like a bat out of hell and sucked the numbers down. Or happen to be towing at the time (firewood to New Meadows, ID) Still the #1 factor of all this is speed and driving style. Poor driving style can ruin a good MPG...